JPH10147009A - Image processing device - Google Patents

Abstract

(57) Abstract: The present invention provides an image processing apparatus that eliminates edges of an image while leaving a minimum pixel width suitable for the resolution of the image, improves image quality, and reduces the number of recording materials. An image processing circuit detects an upper and lower edge of a black region of an image of input image data by an edge detection unit, and outputs a detection result to an AND circuit. The connectivity when the edge pixels of the input image data are deleted with the minimum pixel width set by the width instruction key 30 is determined, and the determination result is output to the AND circuit 43. The AND circuit 43 calculates the logical product of the output of the edge detecting unit 41 and the connectivity determining unit 42 and outputs the logical product to the AND circuit 44. The AND circuit 44 calculates the logical product of the output of the AND circuit 43 and the input image data to obtain a line memory. 15 is output. That is,
If the input image data is a black pixel, the edge detection unit 41 determines that the pixel is an edge pixel, and the connectivity determination unit 42 determines that the pixel is a non-connection point, the image processing circuit 40 determines that the black pixel is a white pixel, Outputs the same image data as the data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus, and more particularly, to an image processing apparatus that reduces consumption of a recording material while suppressing deterioration of image quality and character readability.

[0002]

2. Description of the Related Art Most image processing apparatuses such as printers and facsimile apparatuses have a function of suppressing the consumption of recording materials (hereinafter referred to as an econo mode), and output received images from a facsimile apparatus and output from a printer. It is used to reduce the consumption of recording materials, for example, toner, in the output of a copying machine.

A conventional image processing apparatus equipped with such an econo mode is disclosed, for example, in Japanese Patent Application Laid-Open No. Hei 2-14457.
There is an electrophotographic printer device disclosed in Japanese Patent Application Publication No. 4 (1994) -107, and when the toner saving mode is designated, the printer device reduces the toner consumption by performing a thinning process of dot data of an image portion. ing.

Such a thinning process generally includes an image processing circuit 1 as shown in FIG.
A thinning processing unit 2, an edge detection unit 3, an OR circuit 4, and the like are provided. That is, input image data read by a scanner or the like is input to the thinning processing unit 2 and the edge detection unit 3 of the image processing circuit 1. When the input image data is a monochrome binary image, black is “1”, When white is a binary image of “0” and is a color or monochrome gray scale, the binary image is image-processed in advance.

The edge detecting section 3 and the thinning processing section 2 operate according to a timing signal giving the coordinates (x, y) of each pixel, and perform thinning processing by a bit pattern as shown in FIG. 33, for example.

[0006] For example, the thinning-out processing unit 2 calculates the coordinates (x1, y
When the coordinates of the pixel 1) are x1 = y1 = odd number or even number (in FIG. 33, x1 = y1 = 0, x1 = y1 =
In the case of 1, the signal of the black pixel "1" is output, and in the other cases, the signal of the white "0" is output to the OR circuit 4. The edge detection unit 3 outputs a signal of “1” to the OR circuit 4 if it is an edge, and outputs a signal of “0” if it is not an edge. The OR circuit 4 takes the logical sum of the output from the thinning processing unit 2 and the output from the edge detection unit 3 and outputs the result as output image data to an electrophotographic image forming process or the like. Therefore, the output circuit data is output from the OR circuit 4 while the pixels at the edge portions remain black and the black pixels other than the edge portions have a halftone dot pattern.

[0007]

However, in such a conventional image processing apparatus, in order to reduce toner consumption in the econo mode, the thinning process is performed on the black pixels. Readability (readability)
And the image quality of the copy output deteriorates. In particular, in a generation copy (a copy in which the output of the econo mode is a document), depending on the characteristics of the image forming process, dot thinning or missing dots of the thinning pattern occur, further deteriorating the image.

That is, when the toner reduction process is performed by the above-described conventional thinning process, for example, a thinning bit pattern shown in FIG. 33 is used for an input image as shown in FIG. Is performed, the thinning process is performed on the entire black region of the input image, and the output image becomes blurred as a whole as shown in FIG. 35, and the readability in the case of a character image deteriorates. There is a problem that image quality is deteriorated. In particular, the deterioration of the image quality also changes depending on the resolution of the image data to be processed, and there is a demand for a process of deleting input image data according to the resolution of the image data.

Therefore, the invention according to claim 1 detects an edge of a black area of an image, deletes the edge of the black area, and deletes the image of the minimum pixel width designated by the minimum pixel width designating means. If the minimum pixel width is specified according to the resolution of the image data by deleting the edges so that it remains in the image of the image, the minimum pixel width appropriate for the resolution of the image data can be specified without performing the conventional thinning processing of the black area To reduce the amount of recording material consumed while maintaining good readability and good image quality during copying, while maintaining good readability and good image quality during copying. It is an object of the present invention to provide an image processing apparatus capable of performing such processing.

According to a second aspect of the present invention, the edge of a black area of an image is detected, the edge of the black area is deleted, the resolution of the image data is detected, and the lowest pixel suitable for the resolution of the image data is detected. By deleting the edges so that the image of the width remains in the image after deletion, without performing the conventional black area thinning process, the generation automatically while leaving the minimum pixel width appropriate for the resolution of the image data An image processing device capable of reducing the consumption of recording material while maintaining good readability and good image quality at the time of copying by thinning characters without causing line breaks during copying. It is intended to provide.

According to a third aspect of the present invention, an edge of a black region of an image is detected, the edge of the black region is deleted, a communication recording mode for recording received image data, and image data of a document read are recorded. Of the conventional black recording area by detecting which mode is the copy recording mode to be used, and deleting the edges so that the image having the minimum pixel width suitable for the recording mode remains in the deleted image. Without processing, while automatically leaving the minimum pixel width appropriate for the resolution of the image data in the recording mode, the characters are thinned without line breaks during generation copy, and good readability and An object of the present invention is to provide an image processing apparatus capable of reducing the consumption of a recording material while maintaining good image quality at the time of copying.

According to a fourth aspect of the present invention, the image data is subjected to matrix processing to detect the edge of the black region of the image of the image data, so that the edge of the black region of the image can be appropriately detected with a simple circuit configuration. It is an object of the present invention to provide an inexpensive image processing apparatus which can detect and reduce the consumption of a recording material while maintaining good readability and good image quality at the time of copying.

[0013]

According to the first aspect of the present invention, when an image is recorded on recording paper using a predetermined recording material based on digital image data, a predetermined pixel is formed. In the image processing device that deletes the image and records the image, and saves the recording material, an edge detecting unit that detects an edge of a black region of the image of the image data,
An edge deletion unit that deletes an edge of the black region based on a detection result of the edge detection unit; and a pixel width of the image is smaller than a predetermined minimum pixel width when the edge of the black region is deleted by the edge deletion unit. Connectivity determining means for determining connectivity as to whether or not a pixel width, minimum pixel width instructing means for instructing the minimum pixel width determined by the connectivity determining means, and a determination result of the connectivity determining means The above object is achieved by providing a deletion control unit for controlling deletion of the edge by the edge deletion unit based on the deletion.

According to the above configuration, the edge of the black area of the image is detected, the edge of the black area is deleted, and the image having the minimum pixel width designated by the minimum pixel width designating means remains in the image after the deletion. When the minimum pixel width is specified according to the resolution of the image data, the minimum pixel width appropriate for the resolution of the image data can be left without performing the conventional thinning processing of the black area. In addition, characters can be thinned without line breaks during generation copying, maintaining good readability and good image quality during copying, and reducing recording material consumption. can do.

According to the image processing apparatus of the present invention, when an image is recorded on recording paper using a predetermined recording material based on digital image data, a predetermined pixel is deleted and the image is deleted. In an image processing apparatus that records and saves the recording material, an edge detection unit that detects an edge of a black region of the image of the image data, and an edge of the black region is deleted based on a detection result of the edge detection unit. Edge deleting means, a resolution detecting means for detecting the resolution of the image data, and a minimum pixel width to be left in the image based on the resolution detected by the resolution detecting means. A connectivity judgment is performed to determine whether the pixel width of the image becomes a pixel width smaller than the set minimum pixel width when the edge of the black area of the data is deleted. Means, by providing, a deletion control means for controlling deletion of said edge by the edge deletion unit based on the determination result of the connection determination means, have achieved the above objects.

According to the above arrangement, the edge of the black area of the image is detected, the edge of the black area is deleted, and the resolution of the image data is detected, and the minimum pixel width suitable for the resolution of the image data is detected. Since edges are deleted so that the image remains in the image after deletion, the minimum pixel width appropriate for the resolution of the image data can be automatically left without performing the conventional thinning processing of black areas, and generation Characters can be thinned without line breaks during copying, maintaining good readability and good image quality during copying, and reducing the consumption of recording materials. it can.

According to a third aspect of the present invention, there is provided an image processing apparatus comprising: a communication unit for communicating image data; a reading unit for reading an image of a document and outputting the image data; and a recording paper using a predetermined recording material. Recording means for recording an image on the
A communication recording mode for recording an image by the recording unit based on the image data received by the communication unit,
A copy recording mode for recording an image by the recording unit based on the image data read by the reading unit,
Having a recording of the image by the recording means,
In an image processing apparatus for recording the image by deleting a predetermined pixel to save the recording material, an edge detecting unit for detecting an edge of a black region of the image of the image data, Edge deletion means for deleting an edge of the black area based on a result, mode determination means for determining the communication recording mode and the copy recording mode,
When the minimum pixel width to be left of the image is set based on the determination result of the mode determination unit, and the edge of the black region of the image data is deleted by the edge deletion unit, the pixel width of the image is set to the minimum pixel. Connectivity determining means for determining connectivity as to whether or not the pixel width is smaller than the width,
The object is achieved by providing a deletion control unit that controls deletion of the edge by the edge deletion unit based on the determination result of the connectivity determination unit.

According to the above configuration, the edge of the black area of the image is detected, the edge of the black area is deleted, the communication recording mode for recording the received image data, and the copy for recording the image data obtained by reading the original. Detecting which of the recording modes, and deleting edges so that the image having the minimum pixel width suitable for the recording mode remains in the image after deletion, performs conventional thinning processing of a black area. Without leaving the minimum pixel width appropriate for the resolution of the image data in the recording mode, and at the time of the generation copy, the characters can be thinned without line breaks. Readability and good image quality at the time of copying can be maintained, and the consumption of the recording material can be reduced.

In each of the above cases, for example, as set forth in claim 2, the edge detecting means may detect an edge of a black area of the image by performing a matrix process on the image data. Good.

According to the above arrangement, the image data is subjected to the matrix processing to detect the edge of the black area of the image of the image data. Therefore, it is possible to appropriately detect the edge of the black area of the image with a simple circuit configuration. With a low-cost configuration, good readability and good image quality at the time of copying can be maintained, and the consumption of the recording material can be reduced.

[0021]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are preferred embodiments of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. The embodiments are not limited to these embodiments unless otherwise specified.

FIGS. 1 to 28 are diagrams showing a first embodiment of the image processing apparatus of the present invention. In this embodiment, the black area of the image data is changed according to the specified minimum pixel width. Is determined, and the edge shaving amount is controlled based on the determination result, and corresponds to claims 1 and 4.

FIG. 1 is a circuit block diagram of a facsimile apparatus 10 to which the first embodiment of the image processing apparatus according to the present invention is applied. In FIG. 1, the facsimile machine 10
A reading scanning unit 11, a reading processing unit 12, a recording scanning unit 13, a recording processing unit 14, a line memory 15, a line memory control unit 16, an information compression / decompression unit 17, a modem 18, a communication control unit 19, a network control unit 20, DMA controller 21, ROM
22, MPU23, RAM24, interface 2
5, a mechanism control unit 26, an interface 27, a panel unit 28, and the like. The above units are connected by a bus 29 including a data bus and an address bus.

The reading scanning section (reading means) 11 includes, for example,
A line image scanner or the like using a CCD (Charge Coupled Device) is used.
Operates under the control of the reading processing unit 12 to read an image of a document at a predetermined resolution and output it to the reading processing unit 12. The reading processing unit 12 operates under the control of the MPU 23 to control the driving of the reading scanning unit 11 and transfer the image data read by the reading scanning unit 11 to the line memory 15 via the bus 29.

The recording scanning section (recording means) 13 includes, for example,
An electrophotographic recording device or the like is used, and a recording processing unit 1 is used.
4 and the line memory 1 via the line memory controller 16.
5 to output a toner image on a recording sheet based on the image data transferred from the recording medium. The recording processing unit 14 is an MPU2
3 to control the drive of the recording processing unit 13;
The image is recorded and output on recording paper.

The line memory 15 stores the information compression / decompression unit 1
The image data encoded (encoded) or decoded (decoded) by the image scanning unit 7 or the image data read by the reading scanning unit 11 is stored for each line. The line memory control unit 16 operates under the control of the MPU 23 and controls writing of image data to the line memory 15 and reading of image data from the line memory 15.

The information compression / decompression unit 17 is for improving the efficiency of image data storage and shortening the transmission time, and encodes image data according to a predetermined encoding method.
Also, it decodes the encoded image data.

A line L, for example, a public telephone line or a dedicated line, is connected to the network control unit 20.
Automatically receives an incoming call from the line L, and performs an automatic call processing to the line L. The modem 18 is connected to the network control unit 2
0, and operates under the control of the MPU 23,
Modulates a transmission signal and demodulates a reception signal. The communication control unit 19 exchanges a facsimile control signal with a facsimile machine of the other party and executes a facsimile communication procedure. The modem 18, the communication control unit 19, and the network control unit 20 function as communication means as a whole.

A DMA (Direct Memory Access) controller 21 directly transfers data between an input / output device and a memory or between memories without passing through the MPU 23.

A ROM (Read Only Memory) 22 stores a basic processing program as the facsimile machine 10 and an image processing program described later.
System data and other various data necessary for executing each of these processing programs are stored in advance.

MPU (Micro Processing Unit) 23
Controls each unit of the facsimile machine 10 based on a program in the ROM 22 to execute basic processing as the facsimile machine 10 and execute image processing described later. In particular, the MPU 23 is provided with an econo mode for reducing the amount of toner consumed when recording the toner image by the recording scanning unit 13, and performs image processing in this econo mode, that is, edge detection processing of a black area of image data,
An edge deletion process based on the edge detection result, a black region connectivity determination process, an edge removal control process based on the black region connectivity determination process, and the like are performed to reduce the toner consumption in the recording scanning unit 13.

A RAM (Random Access Memory) 24 is
It is used as a reception buffer and a transmission buffer, and further as a work memory of the MPU 23, and temporarily stores received image data and transmitted image data, and temporarily stores calculation results of the MPU 23 and the like.

The mechanism control section 26 is a general term for various drivers, sensors, and the like, and is connected to the bus 29 via the interface 25. The panel unit 28 is a general term for an operation unit and a display unit including keys and switches of the facsimile machine 10.
7 and connected to the reading processing unit 12
It is connected to a bus 29 via an interface 25. The panel unit 28 includes a mode switching key for setting / cancelling the econo mode and a minimum pixel width instruction key (minimum pixel width instructing means) 30 (indicating a minimum pixel width of a black region to be left by edge deletion in the econo mode). A copy key for setting a copy recording mode in which an image of a document read by the reading operation unit 11 is recorded on recording paper by the recording operation unit 13 is provided. The MPU 23 operates a key setting of a mode switching key. The econo mode process or the normal mode process is performed according to the state, and the edge deletion process of the black area of the image data is performed in the econo mode while leaving the pixel width at least according to the instruction of the minimum pixel width instruction key 30. When the copy key is turned on, the copy recording is performed.

The MPU 23 includes, as shown in FIG.
The image processing circuit 40 is configured as software or hardware, and the image processing circuit 40 includes an edge detection unit 41, a connectivity determination unit 42, and two AND circuits 43 and 44. The connectivity determination unit 42 has a minimum pixel width instruction key 3 provided on the panel unit 28 of the facsimile device 40.
The minimum pixel width instruction data is input from 0, and the minimum pixel width instruction data is the minimum pixel width that must be left when deleting a thin character in the edge deletion processing. The operator of the facsimile machine 10 designates the minimum pixel width to be left in the shaving process of the edge portion of the black area of the input image data by using the minimum pixel width instruction key 30. As will be described later, for example, when one pixel width is designated as the minimum pixel width from the minimum pixel width instruction key 30, the connectivity determination unit 42 determines the connectivity of the black region with a minimum of one pixel width. The connectivity determination processing is performed so as to maintain the minimum pixel width.
In order to maintain the connectivity of the black area with the pixel width,
Perform connectivity determination processing.

The connectivity determination unit 4 of the image processing circuit 40
2. Image data (input image data) is input from the line memory 15 to the edge detector 44 and the AND circuit 44. In the input image data, black pixels are "1" and white pixels are "0". Is binary image data.

The AND circuit (edge deleting means) 44 includes:
The input image data is input, and the output of the AND circuit 43 is inverted, and the AND circuit 44 takes the logical product of the input image data and the inverted input of the AND circuit 43 and outputs the logical product as the output image data to the line memory 15. Output to

The AND circuit 43 (deletion control means) receives the output of the edge detection unit 41 and the inverted output of the judgment output of the connectivity judgment unit 42.
Takes the logical product of these and outputs the result to the AND circuit 44.

The edge detecting section (edge detecting means) 41
It is detected whether or not the input image data is an edge region of a black region. When the input image data is an edge portion,
“1” is output to the AND circuit 43 when it is a non-edge portion. The edge detection processing by the edge detection unit 41 may detect the edge of the black region by any method as long as it can appropriately detect the edge of the black region of the image of the image data. 41 performs an edge detection process using, for example, a 3 × 3 matrix as shown in FIG. That is, the edge detection unit 41
Of the nine matrix pixels in FIG. 3, the center pixel is set as a target pixel, and when the target pixel is a black pixel as indicated by ●, the image data of the eight surrounding pixels is checked. If there is one or more white pixels, the target pixel is determined to be an edge pixel.

FIG. 4 is a flowchart showing the edge detection processing by the edge detection unit 41. That is, the edge detection unit 41 performs a matrix process on the input image data sequentially input from the line memory 15 and checks whether the target pixel is a black pixel (step S1). If it is not a black pixel in step S1, the edge detection unit 41 determines that the pixel of interest is a non-edge pixel, outputs “0” to the AND circuit 43, and performs edge detection processing on the pixel of interest. The process ends (step S2).

If the pixel of interest is a black pixel in step S1, the edge detection unit 41 checks whether there are any white pixels in the surrounding eight pixels (step S3). If there is no white pixel, it is determined that the target pixel is a non-edge pixel, and “0” is output to the AND circuit 43, and the edge detection process for the target pixel is completed (step S2).

In step S3, when there are white pixels in the surrounding eight pixels, the edge detection circuit 41 determines that the target pixel is an edge pixel, and outputs "1" to the AND circuit 4.
3 to terminate the edge detection processing for the pixel of interest (step S4).

The connectivity determining section (connectivity determining means) 42
The minimum pixel width indicated by the minimum pixel width instruction key 30 is used to prevent characters and lines from being separated or lost when edges of the input image data detected by the edge detection unit 41 are deleted. Is determined. Specifically, the connectivity determination unit 42 maintains the connected pixels in the main scanning direction, maintains the connected pixels in the sub-scanning direction, maintains the connected pixels in the oblique direction,
In order to maintain the width of two pixels, maintain the width of three pixels, reduce the unevenness of a straight line, and maintain an isolated point of 2 × 2 or less, the target pixel of the input image data is a connected pixel in the main scanning direction, Connected pixels, diagonally connected pixels, pixels having a width of 2 pixels, 3
Pixels of pixel width, pixels required to reduce linear unevenness and 2 ×
It is determined whether connectivity is equal to or less than 2 isolated point pixels, and if deleted, maintenance of the connection pixels in the main scanning direction, maintenance of the connection pixels in the sub-scanning direction, maintenance of the connection pixels in the oblique direction, 2 pixels Maintain width, maintain 3 pixel width, reduce linear irregularities and 2 × 2
If it is determined that the connection point interferes with maintenance of the following isolated points, a determination output of “1” indicating the connection point is output to the AND circuit 43, and if it is determined that the connection point is not a connection point,
A determination output of “0” indicating a non-connection point is output to the AND circuit 43.

That is, the connectivity judgment unit 42 calculates the 3 × 3
The connectivity between the target pixel and its surrounding pixels is determined using a 4 × 5 or 5 × 4 matrix. For example,
As shown in FIGS. 5A and 5B, the connectivity determination unit 42 determines that the center pixel of interest is a black pixel (indicated by a black circle), and that the left and right or upper and lower pixels of the pixel of interest are white pixels. (Shown by ○), one or more of the upper or left three pixels indicated by hatching are black pixels, and one or more of the lower or right three pixels are black pixels. In the case of a simple maintenance condition (hereinafter referred to as maintenance condition 1), the target pixel is determined to be one pixel connection point, and the target pixel is connected at the connection point so that the connection in the main scanning direction and the sub-scanning direction is not interrupted. It is determined that there is. In addition, the connectivity determination unit 42
As shown in (a) and FIG. 6 (b), the center pixel of interest is a black pixel (indicated by ●), and two pixels in the diagonal left or right direction of the pixel of interest are white pixels (indicated by ○). , A maintenance condition such that at least one of the remaining three diagonally lower pixels indicated by a hatched circle is a black pixel and at least one of the other three diagonally lower pixels is a black pixel ( In the case of the maintenance condition 2), it is determined that the line is a diagonal line surrounded by white pixels, and in order to prevent the connection of the line (diagonal line) sandwiched between the white pixels in the diagonal direction, The target pixel is determined to be a connection point. Further, the connectivity determination unit 42
As shown in FIGS. 7A, 7B, 7C, and 7D, 3
When the target pixel at the center of the × 3 matrix is a black pixel as indicated by a black circle and one of the pixels located in the oblique direction is a black pixel, one of the five pixels in the range indicated by hatched circles In the case of the maintenance condition in which the above is a black pixel (hereinafter, maintenance condition 3), it is determined that the pixel is a diagonal line, and in order to prevent disconnection in the diagonal direction, the target pixel is connected at the connection point. It is determined that there is.

Further, the connectivity judging section 42 performs the processing shown in FIGS.
As shown in (h), an L-shaped (regardless of the direction of the L-shaped) black pixel is adjacent to the target pixel at the center of the 3 × 3 matrix (hereinafter, referred to as a maintenance condition 4). )
Is determined to be a connection point, and the edge of the pixel of interest is not deleted. In addition, FIG.
In (h), a black pixel indicated by ● in the center of the 3 × 3 matrix is a target pixel, a pixel indicated by ● is a black pixel, a pixel indicated by ○ is a white pixel, and a pixel indicated by neither ○ nor ● is a white pixel And black pixels.

Further, the connectivity judging section 42 determines whether or not the
As shown in (h), a maintenance condition that a black pixel is adjacent to a target pixel at the center of a 3 × 3 matrix in a hook shape (regardless of the direction of the hook) (hereinafter referred to as maintenance condition 5). Is determined to be a connection point, and is not symmetrical to deletion. 9A to 9H, a black pixel indicated by ● in the center of the 3 × 3 matrix is a target pixel, a pixel indicated by ● is a black pixel, a pixel indicated by ○ is a white pixel, and both ○ and ● are shown. Pixels not shown are pixels that may be either white pixels or black pixels.

As described above, when the edges of the input image data detected by the edge detection unit 41 are deleted using the connectivity maintaining conditions 1 to 5, the minimum pixel width instruction key 3
The connectivity determination unit 42 appropriately determines whether or not the connectivity of the black image is maintained at the minimum pixel width designated by 0,
Edge deletion processing can be performed. For example, FIG.
When the edge is deleted from the input image data in which the hollow squares as shown in FIG. 11 are connected without determining the connectivity in the connectivity determination unit 42, as shown in FIG. Is deleted, and the connectivity is lost. However, the connectivity determination unit 42 determines that the maintenance condition 1 to the maintenance condition 5
When the connectivity determination is performed by using, and the pixel determined as the connection point is not set to be symmetrical for deletion, the edge can be deleted while the connectivity is maintained as shown in FIG.

However, only the above-mentioned maintenance conditions 1 to 5 cannot maintain the two-pixel width, and all thin straight lines are detected and held as edges. Therefore,
At 400 dpi, at least one pixel width remains, and 600 dpi
In the case of (1), the following maintenance conditions are required in order to leave at least two pixel widths. In this case, the line width for which a minimum of two pixel widths is to be left is always two or more pixels if the line width is four or more pixel widths. Therefore, the condition for maintaining connectivity when the input pixel has a width of 2 pixels and a width of 3 pixels will be described below.

First, when the input image data is a black image having a width of two pixels in the main scanning direction, that is, as shown in FIGS.
As shown in FIG. 3 (b), the target pixel indicated by a thick square is a black pixel indicated by ●, and one pixel on the right side or one pixel on the left side is a black pixel indicated by ●. In a maintenance condition in which one pixel adjacent to the black pixel on the opposite side is a white pixel as indicated by a circle (hereinafter, maintenance condition 6),
It is determined that the input pixel is two pixels wide in the main scanning direction and is a connection point, and the target pixel is not set as a deletion target. In this case, in order not to leave an end point, FIG.
The cases shown in FIGS. 14A to 14D are not included in the maintenance condition 6. In FIG. 14, the pixel at the position indicated by a thick square is the target pixel, the pixel indicated by ● is a black pixel, the pixel indicated by ○ is a white pixel, and the pixel indicated by neither ● nor 、 is The pixel may be either a white pixel or a black pixel.

Next, when the input image data is a black image having a width of two pixels in the sub-scanning direction, that is, as shown in FIGS.
As shown in FIG. 5 (b), a target pixel indicated by a thick square is a black pixel indicated by a black dot, and an upper pixel or a lower pixel is a black pixel indicated by a black dot. In a maintenance condition in which one pixel adjacent to the black pixel on the opposite side is a white pixel as indicated by a circle (hereinafter, maintenance condition 7),
It is determined that the input pixel is two pixels wide in the sub-scanning direction and is a connection point, and the target pixel is not set as a deletion target. In this case, in order not to leave an end point, FIG.
16A to 16D are not included in the maintenance condition 7. In FIG. 15, the pixel at the position indicated by a thick square is the target pixel, the pixel indicated by ● is a black pixel, the pixel indicated by ○ is a white pixel, and the pixel indicated by neither ● nor ○ is The pixel may be either a white pixel or a black pixel.

When the input image data is 3 in the main scanning direction.
In the case of a black image having a pixel width, that is, as shown in FIG. 17, a target pixel indicated by a thick square is a black pixel indicated by a black dot, and two consecutive pixels on the right side are black pixels indicated by a black dot. On the other hand, in a maintenance condition in which one pixel adjacent to the black pixel on the opposite side is a white pixel as indicated by a circle (hereinafter, maintenance condition 8), the input pixel has a width of three pixels in the main scanning direction, It is determined that it is a connection point, and the target pixel is not set as a deletion target. In this case, in order to avoid leaving an end point, in FIG. 18A and FIG. 18B, five consecutive upper pixels or five consecutive lower pixels are indicated by a circle. As described above, when the pixel is a white pixel, the pixel is not included in the maintenance condition 8 and is to be deleted.

When the input image data is a black image having a width of 3 pixels in the sub-scanning direction, that is, as shown in FIG.
A pixel of interest indicated by a thick square is a black pixel indicated by a black dot, two consecutive pixels on the upper side are black pixels as indicated by a dot, and one pixel adjacent to the target pixel on the opposite side to the black pixel is indicated by a circle. As shown, a maintenance condition of a white pixel (hereinafter, maintenance condition 9)
In, the input pixels are three pixels wide in the main scanning direction,
It is determined that it is a connection point, and the target pixel is not set as a deletion target. In this case, in order to avoid leaving an end point, in the case of FIGS. 20A and 20B,
When five consecutive pixels on the left side or five consecutive pixels on the right side are white pixels as indicated by a circle, they are not included in the maintenance condition 9 and are to be deleted.

However, if the above-mentioned maintenance conditions 8 and 9 are applied as they are, when the input image data is a black image having a width of 3 pixels in both the main scanning direction and the sub-scanning direction, as shown in FIG. An image having a width of 3 pixels in both the sub-scanning directions remains.

Therefore, as shown in FIG. 22, a target pixel indicated by a thick square is a black pixel indicated by a black dot, and three pixels continuing upward are black pixels as indicated by a black dot with respect to the target pixel.
When three consecutive pixels on the left side are black pixels as indicated by ●, the pixels are not included in the maintenance condition and are to be deleted.

If the input image data is not included in the maintenance conditions 8 and 9 that leave an edge in the case of FIG. 22 as described above, the input image data shown in FIG. As shown in the figure, an image having a 3-pixel width in both the main scanning direction and the sub-scanning direction does not remain, and appropriate edge deletion can be performed.

Further, in order to reduce as much as possible the unevenness of the linear portion caused by deleting the edge of the input image data, as shown in FIGS. 24 (a) and 24 (b), Black pixels indicated by ●, three pixels continuing to the left of the pixel of interest are black pixels as indicated by ●, and upper and lower and upper and lower left and right pixels are black pixels as indicated by ●, and The three consecutive pixels on the lower side are black pixels as indicated by ●, and the left and right and lower oblique left and right pixels are black pixels as indicated by 維持.
In 0), the target pixel is determined to be a connection point, and is not a deletion target.

Further, the black pixels of the input image data are 2 × 2
In order to prevent the isolated point from being deleted when it is a smaller isolated point, in the maintenance condition (hereinafter, maintenance condition 11) shown in FIGS. Judgment is not made and is not deleted. Note that FIG.
In 5, the pixel at the position indicated by the thick square is the pixel of interest.
The pixel indicated by is a black pixel, the pixel indicated by ○ is a white pixel, and
Pixels in which neither ● nor ○ are shown are pixels which may be either white pixels or black pixels.

Next, the operation of this embodiment will be described. In the facsimile apparatus 10, at the time of transmission, the MPU 23 controls the reading / scanning section 11 via the reading processing section 12, reads an image of a document, and reads the image data of the document into the reading processing section 12.
Through the line memory 15 once. MPU2
3 removes redundancy while reading image data from the line memory 15 according to the compression mode of the information compression / decompression unit 17, and temporarily stores the data in the RAM 24 via the bus 29. The facsimile apparatus 10 sequentially transfers the image data to the modem 18 via the communication control unit 19 while modulating the image data using the RAM 24 as a transmission buffer, modulates the image data with the modem 18, and then transmits the image data to the line L via the network control unit 20. Send out.
Further, at the time of reception, the facsimile device 10 uses the RAM 24 as a reception buffer via the network control unit 20 and the communication control unit 19 for the received image data, and performs information compression and reception.
The data is transferred to the decompression unit 17, decoded (decompressed) by the information compression / decompression unit 17, and temporarily stored in the line memory 15. The facsimile machine 10 transfers the image data in the line memory 15 to the MPU 23 as necessary, performs various image processing, and stores the image data in the line memory 15 again. Thereafter, the facsimile apparatus 10 transfers the image data from the line memory 15 to the recording processing unit 14, and causes the recording scanning unit 13 to record and output the toner image on recording paper.

The facsimile machine 10 is connected to the MPU 23
As one of the contents of the image processing in, when the econo mode is set by the mode switching key of the panel unit, the image processing for deleting the edge of the black region of the image of the image data is performed.

That is, in the MPU 23, as shown in FIG. 2, the image processing circuit 40 is configured as software or hardware, and the image processing circuit 40 includes the edge detection unit 41 and the connectivity. A determination unit 42 and two AND circuits 43 and 44 are provided. The edge detection unit 41, the connectivity determination unit 42, and the AND circuit 44
From the input image data, the edge detection unit 41
As described above, using a 3 × 3 matrix as shown in FIG. 3, the center pixel is set as a target pixel, and the target pixel is the left edge, the lower edge, and the right edge of the black region of the image of the input image data. An edge determination process as shown in FIG. 4 is performed to determine whether the pixel is an edge or an upper edge, and edge detection is performed. If the pixel of interest is an edge pixel, “1” is displayed.
Is output to the AND circuit 43 if the target pixel is a non-edge pixel.

The input image data from the line memory 15 is input to the connectivity judgment unit 42,
The minimum pixel width set by the operator is input from the minimum pixel width instruction key 30, and the connectivity determination unit 42 detects the input image detected by the edge detection unit 41 with the minimum pixel width indicated by the minimum pixel width instruction key 30. In order to prevent the characters and lines from being separated or lost when the edge pixels of the data are deleted, the connectivity of the characters and lines is determined. More specifically, the connectivity determination unit 42 determines whether or not the target pixel of the input image data has the minimum pixel width indicated by the minimum pixel width instruction key 30 based on the above-described maintenance conditions 1 to 11. It is determined whether the pixel of interest is a point or a non-connection point, and if it is determined that the pixel of interest is a connection point, a determination output of “1” indicating that the pixel is a connection point is output to the AND circuit 43, Is determined, the determination output of “0” indicating the non-connection point is output to the AND circuit 43. The determination output of the connectivity determination unit 42 is inverted and input to the AND circuit 43.

As described above, the edge detection output of the edge detection unit 41 is input to the AND circuit 43, and the output of the connectivity determination result is inverted from the connectivity determination unit 42, as described above. Take the logical product of these and
Output to the AND circuit 44. That is, the AND circuit 43
Is “1” indicating that the edge detection unit 41 is an edge.
Is output, and when the connectivity determination unit 42 outputs “0” indicating that it is a non-connection point, it outputs “1” to the AND circuit 44, and otherwise outputs “0” to the AND circuit 44. Output to

As described above, the AND output of the AND circuit 43 is inverted and input to the AND circuit 44, and the input image data is input to the AND circuit 44. The AND circuit 44 obtains the logical AND of these inputs and outputs the result. The image data is output to the line memory 15 as image data. That is, when the input image data is a black pixel, the edge detection unit 41 determines that the input image data is an edge pixel, and the connectivity determination unit 42 determines that the input image data is a non-connection point, the AND circuit 44 determines the black pixel. The output image data from which the edges have been deleted, that is, the output image data from which the edges have been deleted, is output to the line memory 15, and the other output image data that is the same as the input image data is output to the line memory 15.

When the output image data is accumulated in the line memory 15 in this manner, the facsimile apparatus 10 transfers the image data from the line memory 15 to the recording processing unit 14 and records the toner image by the recording scanning unit 13. Record output on paper.

Therefore, according to the present embodiment, FIG.
When image data as shown in FIG. 6 is input, the input image data is converted to high-resolution image data, for example, 600
When the resolution is dpi, the operator designates a two-pixel width using the minimum-pixel-width instruction key 30. When the two-pixel width is specified by the minimum pixel width specification unit 30, the edge detection unit 4
1 performs edge detection processing and performs edge detection, and the connectivity determination unit 42 sequentially deletes the upper, lower, left, and right edge pixels while maintaining a proper connectivity while leaving at least a two-pixel width. I do. As shown in FIG. 27, the output image in this case is sharp while maintaining the connectivity, and the output image has good character readability and good image quality while reducing toner. .

For example, if the input image data shown in FIG. 26 is image data having a low resolution, for example, 200 dpi
Alternatively, when it is 400 dpi, the operator
One pixel width is designated by the minimum pixel width instruction key 30.
When one pixel width is designated by the minimum pixel width instruction key 30, the image processing circuit 40 performs edge detection processing and edge deletion processing while maintaining the connectivity as described above, and performs at least one pixel processing as shown in FIG. An output image having a pixel width can be obtained. Also in this case, as shown in FIG. 28, it is possible to obtain a clear, high-quality output image with good readability of characters. 26 to 28 are enlarged to show images of the same size, respectively.
This is a 5 point character.

FIGS. 29 and 30 are diagrams showing a second embodiment of the image processing apparatus according to the present invention. In this embodiment, the minimum pixel width after deletion according to the resolution of input image data is shown. Is automatically set, the connectivity of the black region of the image data is determined according to the minimum pixel width, and the edge shaving amount is controlled based on the determination result. Is what you do.

The present embodiment is applied to a facsimile apparatus similar to the facsimile apparatus 10 of the first embodiment, and in the description of the present embodiment, the same configuration as that of the first embodiment will be described. Parts will be described using the same reference numerals.

FIG. 29 is a main circuit block diagram of a facsimile apparatus 50 of the present embodiment. Although not shown, the facsimile apparatus 50 has the same configuration as the facsimile apparatus 10 of the first embodiment. Yes, its MPU2
3 is a software or hardware image processing circuit 5
1 is formed.

The image processing circuit 51 includes an edge detector 41,
A connectivity determination unit (connectivity determination means) 52 and two AND circuits 43 and 44 are provided. The connectivity determining unit 52 includes:
Resolution information of input image data is input from a resolution information acquisition unit (resolution detection unit) 53, and the resolution information acquisition unit 53
Detects the resolution of the input image data and outputs resolution information indicating the detected resolution to the connectivity determination unit 52. That is, for example, when the input image data is received image data, the resolution information acquisition unit 53 acquires the resolution of the input image data from the resolution of the image data notified by the protocol from the partner facsimile machine, and reads the input image data. When the image data is copy image data read by the scanning unit 11, the resolution of the read image data of the scanning unit 11 is known in advance.
The connectivity determination unit 5 determines the resolution information of the acquired input image data.
Output to 2.

The connectivity judging section 52 includes a resolution information acquiring section 5
3, the minimum pixel width is determined based on the resolution information input from Step 3, and the connectivity determination processing is performed on the determined minimum pixel width in the same manner as in the connectivity determination unit 52 of the first embodiment. .

That is, when the resolution information is input from the resolution information acquisition unit 53, the connectivity judgment unit 52 sets the resolution of the input image data indicated by the resolution information to a predetermined value as shown in FIG. Resolution, eg, 400d
Check whether it is higher or lower than pi (step P1), 4
If it is not more than 00 dpi, the minimum pixel width is set to one pixel width, and the process proceeds to the next pixel check (step P2). If the resolution of the input image data exceeds 400 dpi in step P1, the connectivity determining unit 52 sets the minimum pixel width to 2 pixels (step P3), and proceeds to check the next pixel. Then, the connectivity determination unit 52 uses the determined minimum pixel width to prevent characters and lines from being separated or lost when edge pixels of the input image data detected by the edge detection unit 41 are deleted. To determine the connectivity of characters and lines. Specifically, the connectivity determination unit 52 determines that the target pixel of the input image data is one of the above-mentioned maintenance conditions 1 to 11
Is determined as a connection point or a non-connection point on the basis of, and if it is determined that the pixel of interest is a connection point, a determination output of “1” indicating the connection point is output to the AND circuit 43. If it is determined that the point is not a connection point, a determination output of “0” indicating a non-connection point is output to the AND circuit 43.

The connectivity judgment unit 5 of the image processing circuit 51
2. Input image data is input to the edge detection unit 41 and the AND circuit 44 from the line memory 15, and the input image data includes black pixels as in the above-described embodiment.
“1” indicates that the white pixel is binary image data “0”.

Therefore, the facsimile apparatus 50 of the present embodiment automatically determines the resolution of the input image data, sets the minimum pixel width suitable for the resolution of the input image data, and sets the minimum pixel width based on the set minimum pixel width. Thus, it is possible to appropriately determine the connectivity of the image at the time of edge deletion. As a result, without having to input the minimum pixel width each time, it is possible to set the minimum pixel width suitable for the resolution of the input image data and determine the connectivity of the image, and maintain a clear output while maintaining the connectivity. Images can be obtained. As a result, it is possible to easily obtain an output image with good character readability and good image quality while reducing toner.

FIG. 31 is a diagram showing a third embodiment of the image processing apparatus according to the present invention. In the present embodiment, the image processing apparatus according to the third embodiment performs the minimum mode after deletion according to the mode switching operation between the fax mode and the copy mode. By setting the pixel width, according to the minimum pixel width, to determine the connectivity of the black region of the image data, and to control the amount of edge shaving based on the determination result,
This corresponds to claim 3.

This embodiment is applied to a facsimile apparatus similar to the facsimile apparatus 10 of the first embodiment, and in the description of the present embodiment, the same facsimile apparatus as that of the first embodiment will be described. The components will be described using the same reference numerals.

FIG. 31 is a main circuit block diagram of the facsimile apparatus 60 of the present embodiment. Although not shown, the facsimile apparatus 60 has the same configuration as the facsimile apparatus 10 of the first embodiment. Yes, its MPU2
3 is an image processing circuit 6 in software or hardware.
1 is formed.

The image processing circuit 61 includes an edge detector 41,
A connectivity determination unit (connectivity determination means) 62 and two AND circuits 43 and 44 are provided. In the connectivity determination unit 62,
Fax / copy switching instruction section (mode discriminating means) 63
And a mode signal of a fax mode (communication recording mode) and a copy mode (copy recording mode) are input from the CPU. The fax / copy switching instruction unit 63 reads whether the input image data to the image processing circuit 61 is received image data. It is determined whether or not the read image data is read by the scanning unit 11. If the input image data is received image data, a mode signal indicating a fax mode is set. If the input image data is read image data, a mode signal indicating a copy mode is set. Is output to the connectivity determination unit 62. Note that, for example, the connectivity determination unit 62
When the copy key of the panel unit 28 is pressed, it is determined that the input image data is read image data.

The connectivity determining unit 62 determines the minimum pixel width based on the mode signal input from the fax / copy switching instruction unit 63, and determines the minimum pixel width with respect to the determined minimum pixel width.
The connectivity determination processing is performed in the same manner as the connectivity determination section 52 of the first embodiment.

That is, the resolution of an image received by facsimile is usually 8 lines / mm in the main scanning direction and 7.7 lines / mm, 3.85 lines / mm or 1 in the sub-scanning direction.
Although it is 5.4 lines / mm, the resolution of the image in the copy mode is higher than the resolution of the image in the fax mode, and recently, it is often 600 dpi or more. Therefore,
When the mode signal indicating the fax mode is input from the fax / copy switching instruction unit 63, the connectivity determination unit 62 sets one pixel width, which is the minimum pixel width when the resolution is low, as the minimum pixel width, and sets the copy mode. Is input from the fax / copy switching instructing unit 63, the minimum pixel width, which is the minimum pixel width when the resolution is high, is set as the minimum pixel width. Then, the connectivity determination unit 62
In order to prevent the characters and lines from being separated or lost when the edge pixels of the input image data detected by the edge detection unit 41 are deleted at the determined minimum pixel width, the connectivity of the characters and lines is Is determined. Specifically, the connectivity determination unit 6
2 is that the target pixel of the input image data is the above maintenance condition 1
Based on the maintenance condition 11, it is determined whether the pixel is a connection point or a non-connection point. If it is determined that the pixel of interest is a connection point, a determination output of “1” indicating the connection point is output to an AND circuit. 43, and if it is determined that it is not a connection point, a determination output of “0” indicating a non-connection point is output to the AND circuit 43.
Output to

The connectivity determination unit 6 of the image processing circuit 61
2. Input image data is input to the edge detection unit 41 and the AND circuit 44 from the line memory 15, and the input image data includes black pixels as in the above-described embodiment.
“1” indicates that the white pixel is binary image data “0”.

Therefore, in the facsimile apparatus 60 of the present embodiment, the resolution of the input image data is automatically determined according to whether the mode is the facsimile mode or the copy mode, and is suitable for the resolution of the input image data. By setting the minimum pixel width, it is possible to appropriately determine the connectivity of the image at the time of edge deletion based on the set minimum pixel width.
As a result, without inputting the minimum pixel width each time, the minimum pixel width suitable for the resolution of the input image data is set according to whether the mode is the fax mode or the copy mode, and the connectivity of the image is determined. And a clear output image can be obtained while maintaining connectivity. As a result, it is possible to easily obtain an output image with good character readability and good image quality while reducing toner.

Although the invention made by the present inventors has been specifically described based on the preferred embodiments, the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the gist of the invention. It goes without saying that it is possible.

For example, in each of the above embodiments, the present invention is applied to the case where recording is performed by an electrophotographic recording apparatus using toner as a recording material. However, the recording material is not limited to toner. The same applies to ink or the like of an ink jet recording apparatus.

In each of the above embodiments, the case where the minimum pixel width is one pixel width and two pixel widths has been described. However, it goes without saying that the minimum pixel width is not limited to the above case. .

[0085]

According to the image processing apparatus of the present invention, the edge of the black area of the image is detected, the edge of the black area is deleted, and the minimum pixel specified by the minimum pixel width specifying means is detected. Since the edges are deleted so that the image of the width remains in the image after deletion, if the minimum pixel width is specified according to the resolution of the image data, the resolution of the image data can be reduced without performing the thinning process of the conventional black area. A suitable minimum pixel width can be left, and characters can be thinned without line breaks during generation copy, maintaining good readability and good image quality when copying. It is possible to reduce the consumption of the recording material.

According to the image processing apparatus of the present invention, the edge of the black area of the image is detected, the edge of the black area is deleted, and the resolution of the image data is detected. Edges are deleted so that the image with the minimum pixel width suitable for the resolution remains in the image after deletion, so the minimum pixel width appropriate for the resolution of the image data is automatically set without performing the conventional black area thinning process. In addition to being able to leave characters on the recording material, it is possible to make characters thin without generating line breaks during generation copying, maintain good readability and good image quality during copying, and Consumption can be reduced.

According to the image processing apparatus of the present invention, the edge of the black area of the image is detected, the edge of the black area is deleted, and the communication recording mode for recording the received image data and the original are set. The edge is deleted so that the image having the minimum pixel width suitable for the recording mode remains in the image after the deletion by detecting which mode is the copy recording mode for recording the read image data. The minimum pixel width appropriate for the resolution of the image data in the recording mode can be automatically left without performing the thinning process of the black area, and the characters can be thinned without generating line breaks during generation copy. This makes it possible to maintain good readability and good image quality at the time of copying, and reduce the consumption of the recording material.

According to the image processing apparatus of the present invention, the image data is subjected to the matrix processing to detect the edge of the black area of the image of the image data. It is possible to detect the edge of the black area, maintain good readability and good image quality at the time of copying with an inexpensive configuration, and reduce the consumption of the recording material.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a facsimile apparatus to which an image processing apparatus according to a first embodiment of the present invention is applied.

FIG. 2 is a circuit diagram of an image processing circuit formed in the MPU of FIG.

FIG. 3 is a diagram illustrating an example of a matrix used in the edge detection unit in FIG. 2;

FIG. 4 is a flowchart illustrating an edge detection process performed by the edge detection unit in FIG. 2;

FIG. 5 is a matrix diagram showing a condition 1 for maintaining connectivity in the sub-scanning direction and the main scanning direction by the connectivity determining unit in FIG. 2;

FIG. 6 is a matrix diagram showing a condition 2 for maintaining connectivity of an oblique line sandwiched between white pixels in an oblique direction by the connectivity determination unit of FIG. 2;

FIG. 7 is a matrix diagram showing a condition 3 for maintaining connectivity of oblique lines by the connectivity determination unit of FIG. 2;

FIG. 8 is a matrix diagram showing a condition 4 for maintaining connectivity determination by the connectivity determination unit of FIG. 2;

FIG. 9 is a matrix diagram showing a condition 5 for maintaining connectivity determination by the connectivity determination unit of FIG. 2;

FIG. 10 is a diagram illustrating an example of an input image in which a plurality of images are in contact in a diagonal direction and are continuous.

11 is a diagram illustrating the input image shown in FIG.
FIG. 6 is a diagram showing an example of an output image from which edges have been deleted without determining connectivity.

12 is a diagram illustrating the input image of FIG.
FIG. 6 is a diagram showing an example of an output image in which connectivity is determined and edges are deleted in FIG.

FIG. 13 is a matrix diagram showing a maintenance condition 6 for connectivity determination for maintaining a two-pixel width in the main scanning direction by the connectivity determination unit of FIG. 2;

FIG. 14 is a matrix diagram showing an exclusion condition for not leaving an end point under the maintenance condition 6 in FIG. 13;

FIG. 15 is a matrix diagram showing a maintenance condition 7 for connectivity determination for maintaining a two-pixel width in the sub-scanning direction by the connectivity determination unit of FIG. 2;

FIG. 16 is a matrix diagram showing an exclusion condition for not leaving an end point in the maintenance condition 7 of FIG.

FIG. 17 is a matrix diagram showing a maintenance condition 8 of connectivity determination for maintaining a 3-pixel width in the main scanning direction by the connectivity determination unit of FIG. 2;

FIG. 18 is a matrix diagram showing an exclusion condition for not leaving an end point in the maintenance condition 8 of FIG. 17;

FIG. 19 is a matrix diagram showing maintenance conditions 9 for connectivity determination for maintaining a three-pixel width in the sub-scanning direction by the connectivity determination unit of FIG. 2;

FIG. 20 is a matrix diagram showing an exclusion condition for not leaving an end point under the maintenance condition 9 of FIG. 19;

FIG. 21 is a diagram showing an example of an output image in which an input image formed of a hollow square with black pixels having a width of 3 dots and made of hollow squares is subjected to connectivity determination under conditions 1 to 9 and edges are deleted.

FIG. 22 is a matrix diagram showing exclusion conditions for maintaining three pixel widths in the main scanning direction in maintenance conditions 1 to 9;

23 is a diagram illustrating an example of an output image in which the same input image as in FIG. 21 is subjected to connectivity determination by adding the exclusion condition of FIG.

FIG. 24 is a matrix diagram showing maintenance conditions 10 of connectivity determination for reducing the unevenness of a straight line by the connectivity determination unit of FIG. 2;

FIG. 25 is a matrix diagram showing maintenance conditions 11 for connectivity determination for leaving isolated points smaller than 2 × 2 by the connectivity determination unit of FIG. 2;

FIG. 26 is a view showing an example of an input image whose edges are deleted by the facsimile apparatus of FIG. 1 in the econo mode.

27 is a diagram showing an example of an output image in which the edge of the input image shown in FIG. 26 is deleted under the condition that the minimum pixel width is 2 pixels in the econo mode by the facsimile apparatus shown in FIG. 1;

28 is a diagram showing an example of an output image in which the edge of the input image of FIG. 26 is deleted under the condition that the minimum pixel width is 1 pixel width in the econo mode by the facsimile apparatus of FIG. 1;

FIG. 29 is a main part circuit block diagram of a facsimile apparatus to which the second embodiment of the image processing apparatus of the present invention is applied.

30 is a flowchart showing a minimum pixel width determination process by the connectivity determination unit of FIG. 29;

FIG. 31 is a main part circuit block diagram of a facsimile apparatus to which the third embodiment of the image processing apparatus of the present invention is applied.

FIG. 32 is a diagram illustrating an example of an image processing circuit that reduces toner by a conventional thinning process.

FIG. 33 is a diagram showing a bit pattern used for thinning processing in the image processing circuit of FIG. 32;

FIG. 34 is a diagram showing an example of an input image input to the conventional image processing circuit of FIG. 32;

FIG. 35 is a diagram showing an example of an output image obtained by thinning out the input image of FIG. 34 by the conventional image processing circuit of FIG. 32;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Facsimile apparatus 11 Reading scanning part 12 Reading processing part 13 Recording scanning part 14 Recording processing part 15 Line memory 16 Line memory control part 17 Information compression / decompression part 18 Modem 19 Communication control part 20 Network control part 21 DMA controller 22 ROM 23 MPU 24 RAM 25 Interface 26 Mechanism control unit 27 Interface 28 Panel unit 29 Bus 30 Minimum pixel width instruction key 40 Image processing circuit 41 Edge detection unit 42 Connectivity judgment unit 43, 44 AND circuit 50, 60 Facsimile device 51, 61 Image processing circuit 52, 62 Connectivity determination unit 53 Resolution information acquisition unit 63 Fax / copy switching instruction unit

Claims (4)

[Claims] When recording an image on recording paper using a predetermined recording material based on digital image data,
In an image processing apparatus that records the image by deleting predetermined pixels and saves the recording material, an edge detection unit that detects an edge of a black region of the image of the image data, and a detection result of the edge detection unit Edge deletion means for deleting the edge of the black area based on the following formula: and whether or not the pixel width of the image becomes a pixel width smaller than a predetermined minimum pixel width when the edge of the black area is deleted by the edge deletion means A connectivity judging means for judging the connectivity of the pixels, a minimum pixel width instructing means for instructing the minimum pixel width judged by the connectivity judging means, and the edge deleting means based on the judgment result of the connectivity judging means. An image processing apparatus comprising: a deletion control unit configured to control deletion of the edge. 2. A method for recording an image on a recording sheet using a predetermined recording material based on digital image data.
In an image processing apparatus that records the image by deleting predetermined pixels and saves the recording material, an edge detection unit that detects an edge of a black region of the image of the image data, and a detection result of the edge detection unit Edge deletion means for deleting the edge of the black area based on the resolution detection means for detecting the resolution of the image data, the minimum pixel width to be left in the image based on the resolution detected by the resolution detection means Setting, and determining whether the pixel width of the image becomes a pixel width smaller than the set minimum pixel width when the edge of the black area of the image data is deleted by the edge deletion unit. A determination unit; and a deletion control unit that controls deletion of the edge by the edge deletion unit based on a determination result of the connectivity determination unit. Image processing apparatus. 3. Communication means for communicating image data, reading means for reading an image of a document and outputting image data,
A recording unit for recording an image on recording paper using a predetermined recording material, a communication recording mode for recording an image by the recording unit based on the image data received by the communication unit, and the reading unit A copy recording mode for recording an image by the recording unit based on the read image data, and, when recording the image by the recording unit, recording the image by deleting predetermined pixels, In the image processing apparatus that saves the recording material, an edge detection unit that detects an edge of a black region of the image of the image data, and an edge deletion that deletes an edge of the black region based on a detection result of the edge detection unit Means, a mode discriminating means for discriminating between the communication recording mode and the copy recording mode, and leaving the image based on a discrimination result of the mode discriminating means. Setting the minimum pixel width, and deleting the edge of the black area of the image data by the edge deleting means, to determine whether the pixel width of the image is a pixel width smaller than the set minimum pixel width. An image processing apparatus comprising: a connectivity determining unit that determines whether the edge is deleted by the edge removing unit based on a determination result of the connectivity determining unit. 4. The image according to claim 1, wherein said edge detecting means detects an edge of a black area of said image by performing a matrix process on said image data. Processing equipment.