JPH0879541A - Color image processing apparatus and color image processing method - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object of the present invention to provide a color image processing apparatus capable of performing accurate marker edit processing even for a document violating a marking rule and obtaining a desired image output. To do. [Structure] For a pixel of interest (history color, color, region) P1, a region is first determined by using left pixel storage data P2 in the main scanning direction. Next, the history code of the upper pixel P3 in the sub-scanning direction (coded a combination of history color, color, and area) is compared with the determined area, and when a certain condition is satisfied, the area of the upper pixel is selected. replace. At the beginning of the band, since there is no history code in the upward direction, the history code is retrieved from the connecting memory 62 and used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus such as a color copying machine for reading a color-marked original on a monochrome original and performing marker editing processing.

[0002]

2. Description of the Related Art Conventionally, in a marker editing process, a plurality of processes such as filling a closed section or changing a character color are automatically recognized and processed according to a marking method. When a monochrome original is colored with color markers and marker editing is performed, for example, outputs as shown in FIGS. 6A, 6B, and 6C are obtained.

(1) As shown in FIG. 6 (a), when it is desired to paint a predetermined closed section of a document, the inside of the closed section is marked to obtain an output in which the closed section is painted in color. be able to. (2) As shown in FIG. 6B, when it is desired to change the color of the black line of the original, marking is performed so as to include the black line, and the black line is replaced with the color of the marker. (3) As shown in FIG. 6 (c), when it is desired to perform both of the above cases (1) and (2), the closed section is filled with the composite form of (1) and (2) above. Then, the color of the portion included by the marker is replaced with the marker color.

In order to automatically distinguish and process the above (1), (2), and (3) simultaneously, a marking rule (marker coloring condition) as shown in FIGS. 7A and 7B is used. is necessary.

In the case of (1) (filling), the inside of the black frame line 101 is marked as shown in FIG. 7A (marking portion 102), but at that time, the black frame line 101 is marked.
The gap 103 formed on the inside of the gap or the protrusion 104 formed on the outside of the black frame line 101 is allowed within a predetermined range (for example, the width 103a of the gap 103 is within 1 mm,
The width 104a of the protrusion 104 is within 0.3 mm). In the case of the above (2) (color conversion), as shown in FIG.
As shown in (b), the periphery 106 is marked in such a manner as to include the black character 105. At this time, the periphery 106 must be filled over a predetermined range (for example, the protrusion 106a from the black character 105 is 1 mm or more). ).

In addition to this, the black 107 inside the closed section must be separated from the marking part 102 by a predetermined range or more (for example, the marking part 102 and the adjacent black line 107).
And the distance 107a is 1 mm or more). Further, the width 101a of the black frame line 101 serving as the boundary of the closed section needs to be a predetermined value (for example, 0.3 mm) or more, and the coating width of the marker (width of the marking portion 102) 102a is also a predetermined value (for example, 0.3 mm).
mm) or more is required.

Documents satisfying these conditions are subjected to accurate marker editing processing.

[0008]

However, since the marking is performed manually, it is possible that the marking rule is violated to some extent. In this case,
There was a problem that unintended output was obtained. This point will be specifically described with reference to FIGS.

Z1 shown in FIG. 8 (a) is a case where the marking portion 102 extends beyond the allowable range to the outside of the black frame line 101 at the entrance portion of the closed section in the case of performing the filling in (1). . Similarly, Z2 is a case where a gap is generated between the black frame line 101 and the marking portion 102 beyond the allowable range at the entrance portion of the closed section. The output in these cases is in a blank area as indicated by Z1 'and Z2' in FIG.

Z3 shown in FIG. 8B is a case where the marking portion 102 extends beyond the allowable range to the outside of the black frame line 101 at the exit portion of the closed section in the case of performing the filling in (1) above. . Similarly, Z4 is a case where a gap is generated between the black frame line 101 and the marking portion 102 at the exit of the closed section beyond the allowable range. The output in these cases will continue to print colors as indicated by Z3 'and Z4' in FIG.

In view of the above conventional problems, the present invention is capable of performing accurate marker edit processing even for a document that violates a marking rule and can obtain a desired image output. An object is to provide an image processing method.

[0012]

In order to achieve the above object, a color image processing apparatus according to a first aspect of the present invention includes a reading sensor for reading an original and outputting multi-valued data, and a color sensor for the multi-valued data. Coding means for classifying into a plurality of color codes to be expressed, storage means for storing the processing information of one line before the reading sensor, reading means for reading the stored contents of the storage means, and read by the reading means. Output code determining means for determining a plurality of output codes by synthesizing the output data of the encoding means with the output data of the encoding means, and a correcting means for correcting the output code of the output code determining means according to a predetermined correction condition, Storage control means for storing the correction information output from the correction means in the storage means as processing information of one line before, and output corrected by the correction means The over de is obtained an output converting means for converting the multi-value data.

According to a second aspect of the present invention, in the color image processing apparatus according to the first aspect of the present invention, the correction means has a generation means for generating processed information in a sensor alignment direction as the correction information. The output code determined by the output coding means using the processing information of one line before is corrected on the basis of the processed information of the sensor alignment direction.

According to a third aspect of the present invention, in the color image processing apparatus according to the second aspect of the invention, the correction means stores the correction information for one band before and the sensor alignment direction. At the head of the band where the processed information does not exist, there is provided an information retrieving means for retrieving the corresponding correction information from the correction information storage means, and the correction information retrieved by the information retrieving means is used as the correction information for the next band. It's something I remembered for.

In the color image processing method according to the fourth aspect of the present invention, a reading process of reading an original with a reading sensor and outputting multi-valued data, and the multi-valued data are classified into a plurality of color codes expressing colors. Coding processing, read processing for reading the stored contents of the storage means for storing the processing information of one line before the reading sensor, data read by the reading processing, and data coded by the coding processing. An output code determination process for synthesizing a plurality of output codes, a correction process for correcting the output code determined by the output code determination process according to a predetermined correction condition, and correction information in the correction process. A storage control process for storing in the storage means as process information of one line before, and an output code corrected by the correction process are stored in the multilevel data. In which an output conversion processing for converting to output the.

[0016]

According to the present invention having the above-described structure, the multi-valued data obtained by reading the original with the reading sensor is classified into a plurality of color codes, and the processing information one line before the reading sensor is stored in the storage means. . The output code determining means determines the plurality of output codes by combining the data in the storage means and the coded data, and the correcting means determines the output code of the output code determining means according to a predetermined correction condition. to correct. Then, the correction information output from the correction means is stored in the storage means as the processing information of one line before, and the output code corrected by the correction means is converted into multivalued data and output.

Thus, for the pixel of interest to be processed, for example, the already-processed pixel information immediately before in the main scanning direction and the pixel information immediately before in the sub-scanning direction are used to violate the marking rule. Can be corrected by surrounding pixels.

[0018]

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

FIG. 1 is a block diagram showing the schematic arrangement of a full-color copying machine according to an embodiment of a color image processing apparatus of the present invention.

In the figure, reference numeral 1 denotes a CCD line sensor for reading an original image image and outputting RGB data. An amplifier circuit 2 for amplifying the RGB data and an 8-bit digital signal for the amplified RGB data are provided on the output side. A / D converter 3 for quantizing the RGB value, a shading correction circuit 4 for shading correction of the quantized RGB data, a color shift correction circuit 5 for correcting the positional shift of the read RGB data, and the RGB data A black character detection circuit 6 for detecting a black character and generating a black character signal is sequentially connected to a marker editing circuit 7 for carrying out marker editing described later.

Further, on the output side of the marker editing circuit 7, a scaling circuit 8 for scaling the scaling and a control signal for generating a control signal used in a spatial filter circuit 13 and a binarization circuit 15 which will be described later. A generation circuit 9; a LOG conversion circuit 10 that performs LOG conversion according to a LOG table;
Minimum value extraction circuit 11 for extracting the minimum value in the converted CMY (cyan, magenta, yellow) data, and masking / UCR for performing masking and UCR by matrix calculation
A circuit 12, a spatial filter circuit 13 that performs edge enhancement or smoothing processing, a gamma conversion circuit 14 that performs gamma conversion according to a gamma table, and a binarization circuit 15 that binarizes 8-bit multivalued data by a dither method or the like. , CM
A head timing adjustment circuit 16 for adjusting the heads for the four YK (cyan, magenta, yellow, black) colors;
A head driver circuit 17 that drives the adjusted head is sequentially connected, and a four-color (CMYK) BJ ink head 18 is connected to the output side of the head driver circuit 17.

Next, the marker editing circuit 7 will be described in detail with reference to FIG.

The RGB data read by the CCD line sensor 1 is subjected to processing such as LOG conversion, and 1
It is input to the marker editing circuit 7 as CMY data in pixel units. This data has a value of 8 bits (0 to 255). However, when performing marker edit processing, LOG
The conversion circuit 10 and the masking / UCR circuit 12 perform no processing.

The marker editing circuit 7 comprises a marker color discriminating circuit 20, a sub-scanning direction noise removing circuit 30, a main scanning direction noise removing circuit 40, a region determining circuit 50, a region error determination correcting circuit 60, and an output converting circuit 70. Has been done.

The CMY data is input to the black / white judging circuit 21 and the color judging circuit 22 in the marker color judging circuit 20 of FIG. In the black-and-white determination circuit 21, if the minimum value of CMY is above a certain value, it is black, and if the maximum value is below a certain value, it is white. The color determination circuit 22 determines the color by the ratio of the remaining two components after subtracting the minimum value of CMY from each value. The white, black and colors determined by these are converted into color codes corresponding to the following Table 1 by the encoding circuit 23, and the output of the color determination circuit 22 is input to the noise removal circuit.

[0026]

[Table 1] In addition, since halftone output is performed for black, the black density generation circuit 24 determines the density from the black signal indicating whether the black is output from the black and white determination circuit 21 and the color determination circuit 22 and the CMY raw data. produce.

The color code is the subscanning direction noise removal circuit 3
If the number of consecutive pixels of the same color is less than or equal to a certain value, it is determined to be noise and removed. Delay circuit 32
Is a circuit for synchronizing the black density with a delay caused by the processing of the sub-scanning direction noise removal circuit 31.

The main-scanning-direction noise elimination circuit calculates the continuity of pixels of the same color by the logic circuit 41 using the input data and the data delayed by one line by the FIFO, and the FIF
Store in O42. Further, the data of the FIFO 42 is used to determine which of the input data and the output data of the FIFO 43 is to be output as a color code.

Next, the area determination circuit 51 will be described.

This circuit 51 determines which one of the four areas each pixel of the image is. These four areas are (1) normal area, (2) paint area,
(3) line area and (4) in-paint line area.

The normal area is an area that does nothing,
The initial value is set in this area. The paint area is
This is a region where the closed section is painted over. However, the normal area is set on the black line at the boundary. Further, the line area is an area in which black is replaced with a marker color. The in-paint line area is a composite type of the paint area and the line area, and is a line area in the paint area.

As shown in FIG. 3, the area determination circuit 51 has 128 pixels of sensors and each pixel (target pixel P1).
The read data and the storage data of the pixel P2 immediately before in the main scanning direction are stored in the FIFO memory 52.

The memory data stores the paint-determined color that determines the color in the paint area, the line-determined color that determines the color in the line or in-paint line area, the area, and the distance from the black pixel in the main scanning direction. Horizontal black counter, horizontal color white counter that stores the distance from the color or white pixel, the previous color that is the color of the pixel read one line before, and the current color that has changed from the main scanning direction There is a history color that remembers whether or not the color has changed.

The print color is determined by logical synthesis of these data and the read data. The details are shown in Tables 2 and 3 below.

[0035]

[Table 2]

[0036]

[Table 3] In Tables 2 and 3, YBK1: clear with black (clearance pixel number comparator), YBK2: clear with black (extruded pixel number comparator), YIROWHH: clear condition is changed depending on the area (normal: clear with color, (Painting: Clear with color, other than: No clear), N: Paint color, * 1: Processing in parentheses in line only mode, black, color, and white counters are always 1
Set to (Full).

As a simple example, using Tables 2 and 3, when the previous color is white in the paint area and the current color, which is the input data, is the marker color, the vertical and horizontal black distance counters are checked, If it is determined that the color is closer to black, the area becomes the paint area, the current color is printed, and the current color is set as the paint-determined color.

A point to be noted in the above Tables 2 and 3 is that a counter is used, whereby the marking is adjacent to black as long as it is within a certain condition even if the marking is not strictly adjacent to black. It can be treated as if it were. The reason for adopting the allowance of a gap instead of the protrusion as the marking condition is that the protrusion cannot be colored with respect to a pie chart, and the gap can be corrected.

Further, since the counter only looks at the vertical and horizontal directions, even if the marker color is adjacent to black in the diagonal direction, it cannot be detected by the vertical and horizontal counters. In this case, since a malfunction occurs, a tailing process as shown in FIG. 4 is added to the area determination circuit 51 to avoid it. This method replaces the pixel of interest P1 with the previous color if the pixel of interest P1 is white, the previous color is a marker color and is a paint area, and either the vertical or horizontal direction is closer to black. That is, if any of the distances A, B, and C from the black pixel is within 1 mm and the above condition is satisfied, the pixel of interest P1
The white of is the color pixel of the previous line. As a result, the white gap between black and the marker color is processed as if it were the marker color, and it is possible to deal with the gap in the diagonal direction.

Further, the reason why the stored data does not include the vertical distance counter is that it is not necessary to store it because it can be calculated in the sensor currently being read. After the area determination, the color code is input to the area determination correction circuit 61, which is a feature of the present invention. The area determination correction circuit 61 compares the area determination result of the area determination circuit 51 with surrounding pixels and corrects the surrounding pixels when it is determined that the area is included in an incorrect area (details will be described later). ). Further, the connection memory (SRAM) 62 is a memory for storing original data for correcting the previous band due to band crossing.

The color code after the above processing is input to the output conversion circuit 70. This data can be switched to a color code such as data before area determination or data before noise removal by the selector 71, and is input to the print color determination circuit 72.

The print color judging circuit 72 is a circuit for converting a 4-bit color code into CMYK data by using a preset table. As for black, the density is generated by the density generation circuit 73 using the black density generated by the marker color discrimination circuit 20 in order to realize halftone.

The output conversion circuit 70 has three output modes: (1) standard back mode, (2) standard blue back mode, and (3) special blue back mode. The standard back mode is a mode in which the color code generated by the area determination circuit 51 is converted by the CMYK output table shown in Table 4 below and output. In the standard blue back mode, the pixels whose output is determined to be white in the standard back mode are converted into blue and the pixels whose output is determined to be black are converted into white, and are output. can do. The special blue back mode is almost the same as the standard blue back mode, but only the black in the paint area is output as it is.

[0044]

[Table 4] The CMYK data that has undergone the above processing is subjected to processing such as scaling, masking, and binarization shown in FIG. 1 and printed by the printer unit.

Next, the correction circuit 61 will be described in detail.

As described above, when a document that violates the marking rule shown in FIG. 7 is processed, the output shown in FIG. 8 is obtained.

Explaining in detail with reference to Tables 2 and 3, Z1 is accidentally entered into the line area at the entrance of the paint area. When the color changes from white in the normal area to black, there is no black in the surrounding area, so the area enters the line area. Further, the line area is continued in the order of color → black → color, and when the color → white is changed, the normal area is restored.

Therefore, only a part of the paint area is returned to the normal area, and a blank area is produced as indicated by Z1 '.
Similarly, in the case of Z2, there is a blank area as indicated by Z2 '.

Z3 is a problem at the exit of the paint area. When the color of the paint changes to black, it returns to the normal area. However, since it changes from normal black to color again, it enters the paint area. After that, since the paint end condition does not exist, the color is continuously printed. Z4
Since the white gap is too wide when the color of the paint changes to black, it is judged to be black in the paint area and the paint area is continued. Continue printing.

The problem with this approach is that the area information is processed only in the main scan direction and is completely independent of the sub scan direction. For this reason, even though the input data of the adjacent two are the same white, one is the paint area and the other is the normal area, which is not the actual state.

Therefore, the area processed by the area determination circuit 50 only in the main scanning direction is corrected in the sub scanning direction by the correction circuit 60.

As shown in FIG. 5, the pixel of interest (history color, color,
Region P1 for the left pixel P in the main scanning direction
The area is determined using the stored data of 2. The stored data is the information shown in FIG. Next, the upper pixel P in the sub-scanning direction
The history code of No. 3 (coded a combination of history color, color, and area) is compared with the determined area, and when a certain condition is satisfied, the area is replaced with the area of the upper pixel.

At the beginning of the band, since there is no history code in the upward direction, the history code is retrieved from the connecting memory 62 and used. By performing such processing, there is an effect that a region is two-dimensionally determined.

Here, the history code will be described using the history code determination conditions shown in Table 5 below.

[0055]

[Table 5] The history code is 3 bits and takes a value from 0 to 5. The reading color of the pixel of interest (current color in Table 5) is white and the area is normal,
When the history color in the processed storage data in the main scanning direction is black, the history code of that pixel is "0". This code is used as the upper pixel history code shown in the correction condition of the following Table 6 when performing the area correction of the pixel one below.
Hereinafter, history codes 1 to 5 are assigned under the conditions shown in Table 5.

[0056]

[Table 6] Next, the correction conditions will be described.

From the left side of Table 6, the history color of the target pixel, the current color which is the color of the read target pixel, the area determined by the area determination in the main scanning direction, and the sub-scan already determined by the history code determination condition. 4 of the history code of the previous upper pixel in the direction
The area is corrected using one of the conditions, and the history code of the pixel of interest is changed.

In Table 6, only the case where the correction is applied will be described. When no correction is applied, it means that the area is correctly determined.

When it is determined that the history color is black, the pixel of interest is white, and the area is a paint area in the main scanning direction, and the upper history code is "0", the area of interest is too large for the area of interest to correctly paint the area. It corresponds when it cannot be completed. That is, it is unlikely that the pixel one above is white and is in the normal region, but the pixel below it is not in the paint region, so the pixel is corrected to the normal region.

Next, when it is determined that the history color is the marker color, the target pixel is white, and the normal region is in the main scanning direction, and the upper history code is "1", the target pixel correctly enters the paint region. If you can't do it. In other words, if the pixel one level above is in the paint area with white as the history color and is in the paint area, the pixel below it cannot be the normal area, so the pixel is corrected to the paint area.

Next, in the case where it is determined that the history color is the marker color, the target pixel is white, and the area is the paint area in the main scanning direction, and the upper history code is "0", the paint end marker protrudes too much. It corresponds to the case where the paint area cannot be finished. That is, it is not possible that the pixel above is white and is a normal area, but the pixel below it is a paint area, so the pixel is corrected to a normal area.

Finally, when the pixel of interest is in the line area in the marker color and the upper history code is 3, the line area and the paint area are adjacent to each other. to correct.

By performing the processing as described above, a gap or protrusion exceeding the allowable amount as described with reference to FIG. 8 is temporarily in an erroneous area, but is corrected after that to obtain a correct image. Output is possible.

The correction conditions of the above embodiment can be changed. Specifically, when the current color in Table 6 is the marker color and is in the line area, even if the upper history code is 3, the area is not corrected to the paint area. This is because there are cases where the effect of the correction in Table 6 appears depending on the document that violates the rule, and cases where it does not.

[0065]

As described in detail above, according to the color image processing apparatus of the first invention, the output code of the output code determining means is corrected in accordance with a predetermined correction condition. Even a document that violates the rule can be subjected to accurate marker editing processing, and a desired image output can be obtained.

According to the color image processing apparatus of the second invention, in the above-mentioned first invention, the correction means has a generation means for generating processed information in the sensor alignment direction as the correction information. Since the output code determined by the output coding means using the processing information of one line before the reading sensor is corrected based on the processed information of the sensor alignment direction, the document violating the marking rule is corrected. It can be corrected easily and accurately.

According to the color image processing apparatus of the third invention, in the second invention, the correction means is a correction information storage means for storing the correction information of one band before, and the sensor array. At the beginning of the band in which the processed information of the direction does not exist, there is provided an information extracting means for extracting the correction information corresponding to this from the correction information storing means, and the correction information extracted by the information extracting means is stored in the next band. Since the information is stored for the correction information, it is possible to correct the document that violates the marking rule more accurately.

In the color image processing method according to the fourth aspect of the invention, the reading process, the coding process, the reading process,
Output code determination processing, correction processing, storage control processing,
Since the output conversion process is sequentially executed, it is possible to perform the accurate marker editing process even for a document that violates the marking rule with a simple image processing method, and it is possible to obtain a desired image output.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a full-color copying machine according to an embodiment of a color image processing apparatus of the present invention.

FIG. 2 is a diagram showing an internal configuration of a marker editing circuit 7.

FIG. 3 is a diagram showing stored data at the time of area determination.

FIG. 4 is a diagram illustrating a tailing process.

FIG. 5 is a diagram illustrating a correction method.

FIG. 6 is a diagram showing a marker editing specification.

FIG. 7 is a diagram illustrating a marking rule.

FIG. 8 is a diagram illustrating a conventional problem.

[Explanation of symbols]

 1 CCD line sensor 7 Marker editing circuit 21 Black-and-white judgment circuit 22 Color judgment circuit 23 Coding circuit 24 Black density generation circuit 51 Area judgment circuit 52 FIFO memory 61 Area judgment correction circuit 62 Connection memory 72 Print color judgment circuit 73 Density generation circuit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kiyohisa Sugishima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masayuki Hirose 3-30-2 Shimomaruko, Ota-ku, Tokyo Kya Non-Incorporated (72) Inventor Shigeo Yamagata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Koji Arai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshio Hayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. A reading sensor for reading a document and outputting multi-valued data, a coding means for classifying the multi-valued data into a plurality of color codes expressing colors, and a process one line before the reading sensor. A storage unit that stores information, a reading unit that reads out the stored contents of the storage unit, an output that determines a plurality of output codes by combining the data read by the reading unit and the output data of the encoding unit Code determining means, correcting means for correcting the output code of the output code determining means according to a predetermined correction condition, and correction information output from the correcting means is stored in the storage means as processing information of one line before. Storage control means and output conversion means for converting the output code corrected by the correction means into multi-valued data and outputting the multi-valued data. The color image processing apparatus. 2. The correction means has a generation means for generating processed information in the sensor alignment direction as the correction information, and is determined by the output encoding means using the processing information of one line before the reading sensor. Output code
The color image processing apparatus according to claim 1, wherein the color image processing apparatus is configured to perform correction based on processed information of the sensor alignment direction. 3. The correction means includes: correction information storage means for storing the correction information of one band before; and correction information storage means at the head of the band where the processed information of the sensor arrangement direction does not exist. 3. The color image processing according to claim 2, further comprising: information extracting means for extracting the correction information corresponding to the correction information, wherein the correction information extracted by the information extracting means is stored for the correction information of the next band. apparatus. 4. A reading process of reading a document using a reading sensor to output multi-valued data, an encoding process of classifying the multi-valued data into a plurality of color codes representing colors, and a reading process of the reading sensor. A read process for reading the stored contents of the storage means for storing the process information of one line before, and the data read by the read process and the data coded by the coding process are combined to generate a plurality of output codes. Output code determination processing for determining, correction processing for correcting the output code determined by the output code determination processing according to a predetermined correction condition, and correction information in the correction processing as processing information of one line before the storage means And a storage control process for storing the output code corrected by the correction process into multivalued data and outputting the converted output code. A method for processing a color image, which comprises: