JPH10200733A - Image processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image processing unit by which a width of a contour is freely adjusted. SOLUTION: An image signal read from an image input section 30 is stored in an image storage section 60. Then the operator uses an operation section 10 to set and enter an entire magnification of the image and a width of a contour desired to be obtained. Then a magnification decision section 95 decides a magnification in a 2nd magnification conversion processing section 80 based on the width of the contour to be set and decides the magnification of the 1st magnification conversion processing section 70 based on the magnification and the entire magnification. Then magnification conversion processing by the 1st magnification conversion processing section 70, contour emphasis processing by an image processing section 90 and magnification conversion processing by the 2nd magnification conversion processing section 80 are executed for the image stored in the image storage section 60. In this case, each magnification conversion processing is executed according to the magnification decided by the magnification decision section 95.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus for performing predetermined image processing including contour enhancement processing and magnification conversion processing on an image.

[0002]

2. Description of the Related Art Generally, an image processing apparatus optically reads a document by an input scanner or the like, converts the read analog signal into a digital signal, and then performs predetermined image processing such as edge enhancement processing and noise removal processing. And output it as a film or plate from an output device to perform a series of image processing.

Here, the above-described contour emphasis processing is performed in order to emphasize a contour portion such as a picture in an image and to sharpen the picture or the like. FIG. 4 is a diagram for explaining the outline emphasis processing. In this figure, the horizontal axis indicates the pixel position, and the vertical axis indicates the level of the pixel signal.

[0004] As shown in the figure, the main signal S of an image has high and low levels, that is, shading, depending on the pixel position, and the boundary portion of the shading is the contour portion of the image. In the contour enhancement processing, first, the image is scanned with a filter composed of a local pixel group (for example, a 3 × 3 pixel matrix), and a weighted average of the signal values in the local pixel group is calculated. Obtain signal U. Then, from the main signal S to the unsharp signal U
Is subtracted to calculate an unsharp mask signal (SU) serving as a basic signal for contour enhancement. Thereafter, the unsharp mask signal (SU) is multiplied by an intensity coefficient k for contour enhancement to obtain a contour enhanced signal k (SU).
By adding (SU) to the original main signal S, an edge-enhanced signal (S + k (SU)) is obtained.

As a result of the above calculation, as shown in FIG. 4, the shading of the outline of the image is emphasized and sharpened. Here, the portion represented by the length “d” in the drawing is the width of the contour portion where the contour is emphasized (hereinafter, referred to as “edge width”).

[0006]

Incidentally, there is a case where it is desired to adjust the above-mentioned edge width to an optimum width in accordance with the type of the image or the background.

Conventionally, an image is often enlarged (expanded) and output. In such a case, the image is enlarged to an image having a desired magnification and then subjected to image processing such as contour enhancement. I have. When the image is enlarged in this manner, the appearance and the like of the original image are changed, and therefore, there is a case where the edge width needs to be changed as appropriate.

In such a case, conventionally, the edge width has been adjusted by changing the size of a filter to be scanned during the outline emphasis processing. That is, for example, by changing a 3 × 3 pixel matrix to a 5 × 5 pixel matrix, the edge width can be increased by about 5/3.

However, according to the above-described method, the edge width is adjusted according to the size ratio of the filter, so that the edge width cannot be finely adjusted. Furthermore, increasing the size of the filter has a significant effect on the quality of the image and also reduces the operation speed, so that it is extremely difficult to freely select the filter size ratio. For this reason, there has been a problem that the edge width cannot be appropriately adjusted.

The present invention has been made in consideration of the above problems, and has as its object to provide an image processing apparatus capable of freely adjusting the width of a contour portion.

[0011]

According to a first aspect of the present invention, there is provided an image processing apparatus for performing predetermined image processing including contour enhancement processing and magnification conversion processing on an image. a) First to perform magnification conversion processing on an image
Magnification conversion processing means, (b) image processing means for performing predetermined image processing including the contour enhancement processing on the image processed by the first magnification conversion means, (c) after the predetermined image processing Second magnification conversion processing means for performing a magnification conversion process on the image.

According to a second aspect of the present invention, there is provided the image processing apparatus according to the first aspect, wherein (d) a set value input for inputting a set value for a width of a contour portion in the image after the contour emphasis processing. Means, and (e) a magnification determining means for determining a magnification in the second magnification conversion processing section based on the set value.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an image processing apparatus 100 according to the present invention.
FIG. 2 is a block diagram showing an electrical configuration of the embodiment. The image processing apparatus 100 includes a control unit 50, an operation unit 10, a display unit 20
, An image input unit 30 and an image output unit 40.

The operation unit 10 is a means for an operator to give an instruction to the image processing apparatus 100, and comprises a keyboard and a mouse. As will be described later, the operation unit 10 also has a function as a set value input unit for inputting a set value of the overall magnification and a set value of the edge width. The display unit 20 is a display on which an operator can confirm an image to be processed and a message from the control unit 50. Further, the image input unit 30
Is an input unit (such as an input scanner) for reading an image to be processed and inputting image data of the image to the image processing apparatus 100. The image output unit 40 outputs the processed image. Output means (output scanner, imagesetter, etc.).

In the above-described image processing apparatus 100, the operator gives an appropriate command to the control unit 50 via the operation unit 10 so that the image data of the image input from the image input unit 30 can be subjected to a magnification conversion described later. Processing and contour enhancement processing. And the operator
The processing result can be visually recognized on the display unit 20, and the final output result can be confirmed by outputting from the image output unit 40.

The control unit 50 is a main unit of the image processing apparatus 100 that performs a magnification conversion process, an outline emphasis process, and the like, and includes an image storage unit 60, a first magnification conversion processing unit 70, and a second magnification conversion processing unit 80. , An image processing unit 90, and a magnification determining unit 95. The image storage unit 60 is a RAM that stores an image processing program and image data. A magnetic disk or the like is connected to the image storage unit 60 in an auxiliary manner.
A program or data may be read from the magnetic disk.

The first magnification conversion processing section 70 and the second magnification conversion processing section 80 are processing sections for performing magnification conversion of an image, respectively, and the image processing section 90 performs contour enhancement processing and noise removal processing on the image. It is a processing unit. The magnification determining unit 95 is a processing unit that determines a conversion magnification executed in the first magnification conversion processing unit 70 and the second magnification conversion processing unit 80. The processing contents of each of these processing units will be further described later.

Next, an image processing procedure in the image processing apparatus 100 will be described. FIG. 2 is a flowchart for explaining an image processing procedure in the image processing apparatus 100. Here, enlargement processing and contour enhancement processing are performed on the image.

First, prior to image processing, a document of an image to be processed is read by the image input unit 30 and transferred to the control unit 50 (step S1). Then, the read image is stored in the image storage unit 60 as an image signal represented by a digital signal. At this time, it is not necessary for the image input unit 30 to read the document every time the image processing is performed, and an image signal that has been read in the past and previously stored on a magnetic disk or the like may be extracted.

Next, the flow advances to step S2 to set the overall magnification of the enlargement processing for the image. Here, the overall magnification is a final magnification for the original image, and the operator inputs the set value via the operation unit 10. In this example, the final magnification, that is, the total magnification is set to 10 times.

Next, the flow advances to step S3 to set an edge width. The edge width to be set here is the width of the contour part of the finally obtained image, that is, the width of the contour part suitable for the image after the final processing. An operator inputs the set value via the operation unit 10.

When the above setting input is completed, the magnification determining unit 95 determines the second magnification (step S4). The second magnification is a magnification applied in the second magnification conversion processing unit 80. Then, the second magnification is determined based on the set value of the edge width input in step S3. FIG. 3 is a diagram for explaining how the second magnification is determined based on the set value of the edge width. As shown
The second magnification is determined so as to be proportional to the set value of the edge width. This is because, as will be described later, the outline portion after the outline emphasis processing is subjected to magnification conversion according to the second magnification. In other words, the edge width of the finally obtained image is the second magnification. Because it is defined by To determine the second magnification, specifically, the magnification determining unit 95 is provided with a look-up table as shown in FIG. 3, and the magnification determining unit 95 refers to the lookup table and sets the edge width set value. Execute based on

Returning to FIG. 2, the process proceeds to step S5, in which the magnification determining section 95 determines the first magnification. The first magnification is a magnification applied in the first magnification conversion processing unit 70. Then, the first magnification is determined based on the overall magnification and the second magnification. That is, the result of dividing the overall magnification by the second magnification is determined as the first magnification. For example,
In this example, since the set value of the overall magnification is set to 10 times, when the second magnification is determined to be 4 times, the first magnification is determined to be 2.5 times and the second magnification is determined to be 2 times. In this case, the first magnification is determined to be 5 times.

After the first and second magnifications are determined as described above, the first magnification conversion processing unit 70 executes the magnification conversion processing on the image stored in the image storage unit 60. (Step S6). First magnification conversion processing unit 70
Executes a magnification conversion process on the image according to the first magnification determined in step S5. Here, the magnification conversion process is a process of enlarging or reducing the size of an image by increasing or decreasing the total number of pixels of the image. Specifically, in the case of the enlarging process, pixel conversion is performed by interpolating pixel signals. In the case of a reduction process, the number of pixels is reduced by thinning out pixel signals. For example, when the first magnification is 2.5, the number of pixels in the vertical and horizontal directions of the image is multiplied by 2.5, and the signal of the increased pixel is the signal of the pixel before enlargement. By interpolation.

After the magnification conversion processing by the first magnification conversion processing section 70, the process proceeds to step S7, where the image processing section 90 executes an outline emphasis processing on the image after the magnification conversion processing. The details of the outline emphasis processing are as described with reference to FIG. 4. Here, the signal of the image on which the magnification conversion processing has been performed based on the first magnification is the main signal S. Note that the local pixel group forming the filter for obtaining the unsharp signal U may be fixed to a 3 × 3 pixel matrix as in the related art. Also,
In step S7, the image processing unit 90 may perform general image processing such as noise removal processing in addition to the outline enhancement processing.

As a result of the outline emphasis processing, an edge width corresponding to a filter composed of a 3 × 3 pixel matrix is formed.
Since this edge width is a value determined by the size of the filter, it is substantially constant as long as a filter composed of a 3 × 3 pixel matrix is used.

Next, proceeding to step S8, the second magnification conversion processing section 80 executes magnification conversion processing on the image signal after the outline enhancement processing. Here, the second magnification conversion processing unit 80
Performs a magnification conversion process on the image according to the second magnification determined in step S4. The contents of the magnification conversion processing are the same as described above. Thus, for example, the second
When the magnification is four times, the number of pixels in each of the vertical and horizontal directions of the image is quadrupled, and the signal of the increased pixel is
It is obtained by interpolating the signal of the pixel before enlargement.
Then, at this time, the edge width after the contour emphasis processing is also scaled according to the second scaling factor. If the second scaling factor is four times, the edge width is also quadrupled.

Then, finally, the process proceeds to step S9, and the image subjected to the image processing is output to a plate or a film by the image output unit 40, and a series of processes ends.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.
For example, in the above-described embodiment, the second magnification is determined by the magnification determining unit 95 based on the set value of the edge width. However, the second magnification is determined by the operator directly inputting the set value via the operation unit 10. It may be. In this case, since the second magnification is directly set, the processing speed is improved. However, according to the above-described embodiment, the edge width can be easily set even by a skilled operator.

Further, in the above embodiment, the image is enlarged by setting the overall magnification to 10 times. However, the present invention is not limited to this, and an arbitrary value can be set as the overall magnification. Therefore, for example, setting the overall magnification to 1x,
If the first and second magnifications are set to 0.25 times and 4 times, it is possible to increase only the edge width without enlarging the image. Furthermore, it is also possible to reduce the image and adjust the edge width.

Further, it is possible to set an arbitrary value for the edge width or the set value of the second magnification. For example, the total magnification is set to 5 times, the first magnification and the second magnification are set to 10 times,
If it is 0.5 times, the edge width can be reduced while enlarging the image.

[0033]

As described above, according to the first aspect of the present invention, the first magnification conversion processing unit for performing the magnification conversion processing on the image, and the image after the processing by the first magnification conversion unit are processed. Since the image processing unit includes an image processing unit that performs predetermined image processing including contour enhancement processing and a second magnification conversion processing unit that performs magnification conversion processing on the image after the predetermined image processing, The width of the outline part can be freely adjusted according to the conversion magnification in the second magnification conversion processing unit. Further, the overall magnification of the image is determined by a combination of the magnification conversion by the first magnification conversion processing unit and the magnification conversion by the second magnification conversion processing unit before the outline enhancement processing,
The overall magnification of the image can be changed independently of the adjustment of the width of the outline portion.

According to the second aspect of the present invention, the set value input means for inputting the set value for the width of the outline portion in the image after the outline enhancement processing, and the second magnification conversion processing based on the set value Since the image forming apparatus further includes a magnification determining means for determining a magnification in the portion, the width of the contour portion can be easily adjusted.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an electrical configuration of an image processing apparatus according to the present invention.

FIG. 2 is a flowchart illustrating an image processing procedure in the image processing apparatus of FIG. 1;

FIG. 3 is a diagram for explaining how a second magnification is determined based on a set value of an edge width.

FIG. 4 is a diagram for explaining contour enhancement processing.

[Explanation of symbols]

 Reference Signs List 10 operation unit 70 first magnification conversion processing unit 80 second magnification conversion processing unit 90 image processing unit 95 magnification determination unit 100 image processing device

Claims (2)

[Claims] An image processing apparatus for performing predetermined image processing including contour enhancement processing and magnification conversion processing on an image, comprising: (a) first magnification conversion processing means for performing magnification conversion processing on an image; b) image processing means for performing predetermined image processing including the contour emphasis processing on the image processed by the first magnification conversion means; and (c) magnification conversion processing on the image after the predetermined image processing. An image processing apparatus comprising: a second magnification conversion processing unit that performs the following. 2. The image processing apparatus according to claim 1, wherein: (d) a setting value input unit for inputting a setting value for a width of a contour portion in the image after the contour enhancement processing; and (e) the setting value. And a magnification determining unit for determining a magnification in the second magnification conversion processing unit based on the image processing apparatus.