JPH0498371A - Picture processing system - Google Patents

Abstract

PURPOSE:To reduction-convert and smooth a binary picture by reading the value of picture elements in a small area in a previously decided processing unit, counting and adding the picture elements in the processing unit, which belong to the small area, only when all are not white or black. CONSTITUTION:A read means 13 reading the value of the picture elements in the small area in the previously decided processing unit at the time of counting the number of the black picture elements or that of the white picture elements in the small area in the binary picture and a deciding means 14 deciding whether the values of the picture elements in the processing unit are all white or black are provided. Then, a counting/addition means 15 counts the picture elements in the processing unit, which belong in the small area, only when all are not white or black. Thus, a problem that the number of the picture elements becomes enormous and the time required for the processing can be eliminated since all the picture elements are fetched one by one so as to add them. Thus, the number of the black or white picture elements in the binary picture can be counted at high speed and picture conversion can be executed.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention counts the number of black pixels or white pixels within a predetermined small area of a binary image, and performs image conversion based on the counted number. This relates to an image processing method that performs.

(Prior art 1: To reduce or smooth a binary image, count the number of black or white pixels in a small area consisting of a predetermined number of pixels, and output using the number of black or white pixels calculated by a coefficient. An example of such a method is the "Image Reduction Conversion Method" (Japanese Patent Application No. 17703/1993). The conversion processing method used here is shown in FIG.

Figure 5 shows the original image W at 1/m in the horizontal direction and 1/m in the vertical direction.
An example of reducing the number to /n is shown below. In order to calculate the number of black pixels in a small area of mxn and convert the added value to obtain an output value, after reading the pixel values into the shift register 2 in the adding means 1 in units of, for example, 8 pixels, The mask circuit 3 takes out the pixel values one by one, and the adder circuit 4 adds the black pixel value to 1" and the white pixel value to "0"', stores the added value in the added value memory 5, and performs the addition. A conversion output is obtained by the value conversion means 6.

[Problems to be Solved by the Invention] However, in such a conventional method, ``all pixels are taken out one by one and added, so as the number of pixels increases, the time required for processing also increases.'' was there.

An object of the present invention is to solve the above-mentioned problem that the processing time is enormous, and to provide an image processing method that performs image conversion by rapidly counting the number of black or white pixels in a binary image. .

[Means for Solving the Problems] The image processing method according to the present invention calculates the value of the pixel in the small area from a predetermined value when counting the number of black pixels or white pixels in a small area in a binary image. A reading means for reading in each processing unit and a determining means for determining whether all the pixel values in the processing unit are white or black are provided, and only when the values of the pixels in the processing unit belonging to the small area are not all white or black, the pixel values of the processing unit belonging to the small area are This is done by counting and adding means.

In addition, in the case of white areas, there is a white line skip method used in facsimiles as a method that does not perform any processing, but in this method, the pixel value is determined line by line, so even if there is only one pixel in one line, If there are black pixels, processing will not be skipped, and this method cannot be applied to a method that performs image processing based on the values of pixels in a small area. The white line skip method is different from the white line skip method in that it is provided with means for reading pixel values in smaller reading units than 1 line, and means for adding them for each partial area.

[Operation 1] In this invention, pixel values within a small area are read in a predetermined processing unit, and it is determined whether all pixel values within that processing unit are white or black. Only in this case, the pixels of the processing unit belonging to the small area are counted.

[Embodiment 1] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In this embodiment, in image conversion that reduces a binary image by 1/4 both vertically and horizontally, when the number of black pixels included in a small area consisting of 166 pixels (4×4) is 8 or more, the converted pixel is An example will be explained in which the converted pixel is made black and the converted pixel is made white when the number of black pixels is 7 or less. Further, an example will be explained based on an example in which the unit of reading image data is 8 pixels in the horizontal direction, and it is determined whether all the pixels of the read processing unit are white pixels, and if they are not, the number of black pixels is calculated.

Before explaining the embodiment shown in FIG. 1, image data will be explained with reference to FIG.

FIG. 2 shows an example of image data for explaining one embodiment of the present invention. In the example of image data in FIG. 2, the small areas of the original image W are Ql, Q2 . Q3,...+Q
This is an area consisting of 4×4 pixels indicated by n.

In addition, the reading unit is pH, PI3. PI3. PI3, PI3. P
I3. PI3. There are 8 pixels of PI3. At this time, the partial area of the reading unit corresponding to the small area is pH, PI3
．． PI3. A partial region of PI4, and a partial region of PI3. PI3. P.I.
3. These are two partial areas with the partial area of PI8. Note that codes are written only for important parts.

FIG. 1 is a block diagram for explaining a first embodiment of the present invention. In FIG. 1, 11 is an input device;
12 is an image memory for storing image data written from the input device 11; 13 is a reading unit for reading image data from the image memory 12 in predetermined reading units based on the number of pixels; 14 is this reading unit 1;
15 is a processing means, and a counting means 151 counts the number of black pixels in the partial area of the pixels received from the determination means 14; and counting buffer memories 153 and 15
4, an adding means 152 for adding the output from the counting buffer memory and the counting means 151, and a reading means 155 for reading out the contents of the counting buffer memory. 1
6 is a binarization means that outputs black as a converted pixel when the input is a predetermined value or more, and 17 is a converted image memory.

When the input device 11 writes all the image data to the image memory 12 via the signal line Sl, the input device 11 writes all the image data to the image memory 12 via the signal line Sl, and then writes the data to the counting buffer memory 153 . An instruction is given to initialize the contents of the counting buffer memory 154, and the reading means 13 is activated via the control line C1.

The reading means 13 receives activation from the input device 11 via the control line C1, and from the determining means 14 via the control line C1.
When a request signal is received via 4, the image memory 12 to 8
Image data of a pixel is read as a reading unit through a signal line S2, and output to the determination means 14 through a signal line S3. The reading means 13 also stores image data in four reading units for two small areas (in the first example in FIG. 2, Ql
and the pH corresponding to the Q2 part ~ P18. P21-P28.
P31-P38. P41 to P48) by the determining means 14
After receiving the request signal from the determining means 14 on the control line C4 or the request signal from the processing means 15 on the control line C5, it outputs a read control signal to the processing means 15 on the control line C3.

The determining means 14 reads the reading means 13 via the signal Pa53.
When image data is received from , it is determined whether the image data is all white or not, and if all the pixels are not white, the image data is outputted to the processing means 15 via the signal line S4. Further, when the image data from the reading means 13 are all white pixels, a request signal for the next image data is sent to the reading means 13 via the control line C4.

The processing means 15 converts the image data from the determining means 14 into a signal L.
9 When the output is received via S4, the number of black pixels for each partial area corresponding to the small area included in the output is counted by means 1.
51, the addition means 152 adds the values in the counting buffer memories 153 and 154, sends the result to the counting buffer memory again, and requests the next image data to the reading means 13 via the control line C5. Send a signal. Further, when the processing means 15 receives a read control signal from the reading means 13 through the control line C3, the reading means 155 reads out the contents of the counting buffer memory 153 and the counting buffer memory 154, and sends the contents to the binarizing means 16 via the signal line S5. After that, the contents of each counting buffer memory 153 and 154 are initialized. Further, when the control IS C2 receives a signal from the input device 11, the counting buffer memory 153. The contents of the counting buffer memory 154 are initialized.

The binarization means 16 converts the output from the processing means 15 into a signal line S5.
When the value is received, it is checked whether the value is 8 or more, and if it is 8" or more, a black pixel is output to the converted image memory 17, and if it is less than 8, a white pixel is output to the converted image memory 17.

The operation of the first embodiment of the present invention will be described below, taking as an example the case where the image data shown in FIG. 2 is written as the contents of the image memory 12.

After writing all the image data into the image memory 12, the input device 11 sets the contents of the counting buffer memory 153 and the counting buffer memory 154 of the processing means 15 to "O" using the control line C2, and also sets the contents of the counting buffer memory 153 and the counting buffer memory 154 of the processing means 15 to "O" through the control line C1. The reading means 13 is activated. In response to this activation, the reading means 13 starts reading image data from the image memory 12 in units of eight pixels. In the example in Figure 2, first,
Line pH, PI3. PI3. PI3. PI3, PI
3. PI3. The image data of the pixel of PI3 is shown in Figure 3 (a).
It is read as follows and output to the determination means 14. The determining means 14 determines the pH of the first line in the example of FIG. 2, PI3. PI3
．． PI3. PI5, PI3. PI3. Since all PI3 are white pixels, a request is made to the reading means 13 to perform the next reading through the control line C4.

Next, the second line P21. P22. P23゜P24.
P25. P26. P27. When P28 is read into the reading means 13 as image data as shown in FIG.
Since there are black pixels in 28, the image data is output to the processing means 15.

When the processing means 15 receives the output from the determination means 14, it first selects pixels P21, P22 . P2
3. Counting means 15 for counting the number of black pixels among the four pixels of P24
1, and addition means 152 adds the contents of the counting buffer memory 153 for the small area Ql. Second
In the example shown in the figure, the number of black pixels is 2, which is 1 in the counting buffer memory.
It is placed at 53. Furthermore, the processing means 15 further processes P25. P26. P27. The counting means 151 counts the number of black pixels among the four pixels of P28, and the adding means 1
At step 52, addition is made to the contents of the counting buffer memory 154 for the small area Q2.

In the example of FIG. 2, the number of black pixels, .degree.2.degree., is placed in the counting buffer memory 154. When the counting and addition of black pixels among the two sets of four pixels belonging to the small areas Ql and Q2 is completed, the processing means 15 issues a request signal for the next image data to the reading means 13 via the control line 5.

Hereinafter, when the reading means 13 receives a request signal from the determining means 14 or the processing means 15, the third line CP31 to P
38) Furthermore, the image data of the fourth line (P41 to P48) is read and output to the determination means 14. Second
Similarly to the line, the determination means 14 determines white pixels, and the processing means 1 when all pixels are not white pixels in the read unit.
When the counting and addition of black pixels in each of the small areas Q1 and 02 in step 5 is completed, and a request signal is output from either the determining means 14 or the processing means 15 to the reading means 13, the reading means 13 outputs the request signal to the processing means 15. A read control signal is output to the next small area Q3 through the control line C3. Start reading the image data of Q4.

When the processing means 15 receives a read control signal from the reading means 13, it outputs the contents of the counting buffer memory 153 and the contents of the counting buffer memory 154 to the binarizing means 16, and then outputs the contents of the counting buffer memory 153 and the counting buffer memory 154 to the binarizing means 16. Return the contents to °O”.

When the binarization means 16 receives the output from the processing means 15, it checks whether the value is greater than or equal to °8".
If it is above, a black pixel is output to the converted image memory 17, and if it is less than 8°, a white pixel is output to the converted image memory 17.

Through the above operations, the result of binarization based on the number of black pixels in each of the small areas Ql and Q2 is obtained by the binarization means 16.
, and stored in the converted image memory 17. Thereafter, in the same manner, the first lines P19 to P116 and the second lines P29 to P2, which are the image data of the small areas Q3 and Q4, are
16, 3rd line P39 to P316, 4th line P49
-P416 are sequentially read by the reading means 13, the determining means 14 determines whether the pixels are white, and if all pixels are not white, the processing means 15 selects the small area Q3. The number of each black pixel in Q4 is output, and the value of the converted pixel is determined by the binarization means 16 and stored in the converted image memory 17. Thereafter, by continuing similar processing, a reduced binary image based on the number of black pixels in each small area in the entire screen is stored in the converted image memory 17.

Since it operates in this way, the number of black pixels included in a small area can be counted without the originally unnecessary process of adding "°O", and image conversion can be speeded up.

A second embodiment of the invention will now be described. In the second embodiment, in order to count the number of black pixels faster than in the first embodiment, the reading unit is divided and divided when all the pixel values in the reading unit of image data are not white. It is further determined for each pixel whether all pixels are white, and counting processing is performed only when all pixels are not white. below,
The unit of reading image data is 8 pixels in the horizontal direction,
A second embodiment of the present invention will be described based on the block diagram of FIG. 4, taking as an example a case in which, after determining a white pixel, the pixel is further divided into two parts of four pixels for determination.

In FIG. 4, the input device 119, the image memory 12, the reading means 131, the determining means 14, the binarizing means 16, and the converted image memory 17 are the same as those in the first embodiment.

Reference numeral 141 denotes a secondary judgment means which divides the image data outputted from the judgment means 14 into two parts of 4 pixels each and judges whether all the values of the divided image data are white. When image data is received from the determining means 14 via the image forming apparatus 4, the image data is divided into image data 1 in units of 4 pixels.
and image data 2, and it is determined whether all the pixels are white in the divided unit.If the image data l are not all white pixels, image data 1 is output to the processing means 150 through the signal 1as41, and the control line C41 transmits the image data type l to the processing means 150, and waits for a processing end signal from the processing means 150. Upon receiving this, the process moves to the determination processing of image data 2.

When all of the image data 1 are white pixels, the process moves to the determination process for image data 2. When image data 2 is not all white pixels,
The image data 2 is output to the processing means 150 through the signal line S41, and the image data type 2 is transmitted to the processing means 150 through the control line C41.
It waits for a processing end signal from 0, and upon receiving it, sends a next image data request to the reading means 13 via the control line C5. When all of the image data 2 are white pixels, a request for the next image data is sent to the reading means 13 via the control line C5.

150 is a processing means that counts the number of black pixels in a partial area of pixels received from the secondary determination means 141 and adds them for each small area, and transmits the image data from the secondary determination means 141 to a signal line. When the reception is received via S41, the number of black pixels included in the output is counted by the counting means 151, and if the image data type signal on the control line C41 from the secondary determination means 141 is image data type 1, The adding means 152 adds the value stored in the counting buffer memory 153, stores the result again in the counting buffer memory 153, and sends a processing end signal to the secondary determining means 141 via the control line C42, and outputs an image data type signal. If the image data type is 2, the adding means 152 adds it to the value in the counting buffer memory 154, and the result is added to the counting buffer memory 15 again.
4 and sends a processing end signal to the secondary determination means 141 via the control C line 42.

Further, when the counting means 151 receives a readout control signal from the reading means 13 through the control line C3, the counting means 151
55 reads out the contents of the counting buffer memories 153 and 154 and outputs them to the binarizing means 16 through the signal line S5, and then initializes the contents of each counting buffer memory 153 and 154. In addition, control 1ic from input device 11
2, when the signal is received, the counting buffer memory 15
3. Initialize the contents of 154.

The operation of the second embodiment of the present invention will be described below, taking as an example the case where the image data shown in FIG. 2 is written as the contents of the image memory 12.

The input device 11 writes all the image data to the image memory 12, and the reading means 13 reads it and determines the judgment means 1.
The operations up to step 4 in which white pixels are determined and, if all pixels are not white, image data is output via the signal line S4, are exactly the same as in the first embodiment.

Since the first line of the small areas Ql and Q2 in FIG.
41. The secondary determination means 141 performs P21. P2
2. ......, when the image data of P28 is received via the signal line S4, image data 1 and P2 of P21 to P24 are received.
First, image data 1 is divided into image data 2 from 5 to P28, and a white pixel is determined. In the example of Ward 2, P2
Since black pixels exist in the image data 1 of 1 to P24, the image data type 1 is output to the processing means 150 through the image data 1 and the control line C41, and a processing end signal from the processing means 150 is awaited.

Upon receiving the output from the secondary determination means 141, the processing means 150 determines P21. P22. P23. The number of black pixels among the four pixels of P24 is counted by the counting means 151, and the control line C41
Since the image data type signal from is image data type 1, the adding means 152 adds the contents of the counting buffer memory 153 for the small area Ql and writes the result to the counting buffer memory 153. Then, the secondary determination means 141 is notified of the end of the process via the control line C42. When the secondary determination means 141 receives the end of processing through the control line C42, it determines whether the image data 2 of P25 to P28 is a white pixel, and since there is a black pixel in the image data 2 of P25 to P28, the processing means 150 Image data type 2 is output to the processing means 1 through the image data 2 and control line C41.
Wait for a processing end signal from 50.

When the processing means 150 receives the output from the secondary determination means 141, it operates in the same manner as described above, and since the image data type signal from the control line C41 is image data type 2, the small area Q
The result of counting and addition is written into the counting buffer memory 154 for 2, and the completion of the process is notified to the secondary determining means 141. When the secondary determination means 141 receives the completion of processing through control 19C42, it issues a request signal for the next image data to the reading means 13. Thereby, the process moves to the third line.

In the example of the third line of the small areas Ql and Q2 in FIG.
Since black pixels are included in pixels 1 to P38, the image data is output to the secondary determination means 141. Secondary determination means 141
, since black pixels are included in P31 to P34, image data 1 is sent to the processing means 150, where black pixels are counted and added in the same way as the operation in the example of the second line, and processing is performed from the control line C42. You will be notified of the termination. Secondary determination means 14
1 receives this and determines white pixels P35 to P38. In the example of FIG. 2, since all pixels are white, image data 2 is not output to the processing means 150, and a request signal for the next image data is sent to the reading circuit 13. Thereafter, the processing of the fourth line is performed in the same manner as above, and when this is completed, the addition value is read out in the processing means 150, and the binarization and conversion is performed in the binarization means 16, as in the first embodiment. Writing is performed in the image memory 17, and processing moves on to the next small area.

In this way, the unit of reading is further divided, and when the divided image data is all white, no processing is performed, so it is possible to add °0" more effectively than in the first embodiment. The number of black pixels included in a small area can be counted without unnecessary processing, and image conversion can be speeded up.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a reading means for reading pixel values in a small area in a predetermined processing unit, and a determination as to whether all pixel values in the processing unit are white or black. Since it is equipped with a judgment means that counts and adds up the pixels of a processing unit belonging to a small area only when the pixels are not all white or black, it is possible to replace the conventional method of adding 0゛. Since processing can be omitted, the number of black or white pixels can be counted at high speed, and high-speed conversion and smoothing of binary images that handle a large amount of image data can be realized.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing an example of original image data for explaining this invention, and FIG. 3 is a block diagram showing an example of original image data in the first embodiment. A diagram showing an example of image data when read in units, FIG. 4 is a block diagram showing a second embodiment of the present invention, and FIG. 5 is a block diagram showing an example of a conventional image processing method. . In the figure, 11 is an input device, 12 is an image memory, 13 is a reading means, 14 is a determining means, 15 is a processing means, and 16 is a 2
Value converting means, 17 a converted image memory, 141 a secondary determination means, 150 a processing means, 151 a counting means, 152 an adding means, 153 and 154 a counting buffer memory, 1
55 is a reading means, pH, PI3.・・・・・・P
21. P22,..., P31. P32. ...
..., P41. P42, ..., are input pixels,
Ql, Q2. ...Qn is a small area. Figure 3 pH I2 I3 pH1

Claims (1)

[Claims] In a method of image processing by counting the number of black pixels or white pixels included in a small area of the original image, there is a reading means for reading the value of the original pixel in a predetermined reading unit, and a pixel read by this reading means. determining means for determining whether the values of the read pixels are all white or black, and when the values of the read pixels are not all white or black, the values of the read pixels are black or white pixels for each partial area corresponding to the small area. An image processing method comprising: an addition means for calculating and adding the number of images.