JP2011044919A - Image processing apparatus and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus and program, capable of reliably performing preservation concerning a specified color to be preserved in an image to be processed, so as to perform color reduction processing. <P>SOLUTION: A specified color information setter 2 sets the specified color, its color range, and a designation color first. When the image to be processed is given, a representative color generating part 1 extracts a representative color among the respective pixels of the image to be processed. A specified color replacement processing unit 3 performs replacement processing into the set designation color concerning the pixel with the color within a color range set by the specified color information setter 2 in the image to be processed. Then, finished replacement information is added to the replaced pixel. A color replacing part 4 performs replacement processing into the representative color extracted by the representative color generating part 1 with respect to the image to be processed after processing by the specified color replacement processing unit 3. In this case, no replacement processing into the representative color is performed concerning the pixel with the finished replacement information added thereto. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image processing apparatus and an image processing program.

  Conventionally, a color reduction process for reducing the number of colors used in an image has been performed. In the color reduction processing, for example, some representative colors are extracted from the processing target image, and the colors in the processing target image are replaced with one of the extracted representative colors. By this process, an image in which the colors used are limited to the number of representative colors is obtained. By this color reduction processing, various noises and unevenness included in the image, for example, when the image is a document image read by the image reading device, the document unevenness of printing, scan noise at the time of reading, handwriting When there is a portion, handwriting unevenness is reduced. Further, when compressing an image, the compression rate is improved by performing color separation.

  In general, a specific color such as a logo is required to be stored even when color reduction processing is performed. However, if a specific color is not extracted as a representative color, the specific color to be stored is not stored. For example, in Patent Document 1, a designated important color is added to a representative color to perform color reduction processing.

  When the processing target image is, for example, an image read by an image reading apparatus, the color may be shifted even in a portion where a specific color is used due to the characteristics of the apparatus or reading error. In addition, color unevenness or fluctuation may occur in the processing target image due to various factors. When such an image to be processed is replaced with a representative color including a specific color, even a portion where the specific color is used is not replaced with a specific color, but replaced with another representative color. There was a case where it was done.

JP 2003-288585 A

  An object of the present invention is to provide an image processing apparatus and an image processing program capable of reliably saving a specific color to be stored in a processing target image and performing a color reduction process.

  According to the first aspect of the present invention, a specific color replacement processing unit that replaces a specific color in a color range specified in advance in a processing target image with a corresponding specified color, and the specific color replacement in the processing target image An image processing apparatus comprising color replacement means for replacing an image area other than the image area to be replaced by the processing means with a representative color extracted from the processing target image.

  The invention according to claim 2 of the present application further includes specific color information setting means for setting the specific color, a color range centered on the specific color, and the designated color in the configuration of the invention according to claim 1 of the present application. An image processing apparatus comprising:

  The invention according to claim 3 of the present application is an image obtained by the image reading unit reading the document drawn by the specific color information setting unit in the invention according to claim 2 of the color to be the specific color. The image processing apparatus is characterized in that the specific color is set and the designation of the color range centered on the set specific color is received.

  An invention according to claim 4 of the present application is an image processing program for causing a computer to execute the function of the image processing apparatus according to any one of claims 1 to 3.

  According to the first aspect of the present invention, it is possible to reliably save the specific color of the processing target image and perform the color reduction process.

  According to the second aspect of the present invention, the specific color of the processing target image and the color range to be the specific color can be arbitrarily specified.

  According to the third aspect of the present invention, the specific color of the processing target image can be designated from the image drawn on the read original.

  According to the fourth aspect of the present invention, it is possible to reliably save the specific color of the processing target image and perform the color reduction process.

It is a block diagram which shows an example including one Embodiment of this invention. It is a flowchart which shows an example of the operation | movement in the structural example containing one Embodiment of this invention. It is a flowchart which shows an example of operation | movement of a specific color information setting part. It is explanatory drawing of an example of the original document drawn by the specific color. It is explanatory drawing of an example (before adjustment) of an adjustment screen. It is explanatory drawing of an example (after adjustment) of an adjustment screen. It is explanatory drawing of an example of a process target image. It is explanatory drawing of an example of the image substituted by the specific color replacement process part, and substituted information. It is explanatory drawing of an example of the image to which the color reduction process was performed. It is explanatory drawing of another example of a process target image. FIG. 3 is an explanatory diagram of an example of a computer program, a storage medium storing the computer program, and a computer when the function described in the embodiment of the present invention is realized by a computer program.

  FIG. 1 is a block diagram showing an example including an embodiment of the present invention. In the figure, 1 is a representative color creation unit, 2 is a specific color information setting unit, 3 is a specific color replacement processing unit, and 4 is a color replacement unit. The processing target image may be any image, for example, an image read by an image reading device.

  The representative color creation unit 1 extracts a representative color from the processing target image. As a representative color extraction method, a conventionally used method may be used. For example, a representative color may be determined within a predetermined number of ranges by creating a color histogram from the colors of the pixels of the processing target image and integrating the colors whose frequency values show a peak. Note that the representative color may be determined in advance, and in this case, the representative color creating unit 1 may be omitted.

  The specific color information setting unit 2 sets, for example, a color to be output in a designated color, such as a logo of a company or a brand, as a specific color, sets a color range centering on the set specific color, and sets a specific color. Set the specified color to be replaced. The set specific color and color range and the corresponding designated color are stored. The setting of the specific color may be determined in advance or specified by the user. For example, a document drawn in a color that should be a specific color may be read by an image reading device, a color histogram may be created from the obtained image, and the specific color may be set based on a frequency value peak or the like. The specific color set in this way may be changed by the user.

  The color range can also be set in advance, set using a function determined by a specific color, or specified by the user. For example, the color range may be set from the distribution of frequency values of the color histogram created when setting the specific color. The user may also change the color range set in this way. When the color range is set, if the set specific color is set to be the center, even if a color change such as a color shift occurs, the specific color is replaced. Also, if the color range is expanded, the tolerance for color change increases.

  As the designated color, a specific color may be set, or for example, a color obtained by changing the specific color according to the reading characteristics of the image reading apparatus may be used as the designated color. For example, if an electronic value of a color is determined by a logo or the like, the value may be set as a designated color. The user may also set this designated color.

  The specific color replacement processing unit 3 follows the specific color set by the specific color information setting unit 2 and the color range centered on the specific color and the specified color in the color range centered on the specific color in the processing target image Is replaced with the specified color. Then, replacement information indicating that the replacement of the specific color has been performed is added with one or more replaced pixels as a unit.

  The color replacement unit 4 replaces an image region other than the image region to be replaced by the specific color replacement processing unit 3 in the processing target image with the representative color extracted from the processing target image by the representative color creation unit 1. Whether or not the specific color replacement processing unit 3 becomes a replacement target is determined by whether or not replacement information is added. For the pixels to which the replacement information is added, the color replacement unit 4 does not perform replacement with the representative color, and uses the color after replacement by the specific color replacement processing unit 3 as the output of the color replacement unit 4.

  Thus, the image output from the color replacement unit 4 is an image in which the colors used are limited to the representative color and the designated color. For example, in an image read by an image reading device or a handwritten image, there are more colors than the number of colors recognized by the user as a color in the image due to various factors such as reading error and blurring. A color reduction process is performed to reduce the number of colors used. Moreover, the specific color is replaced with the designated color regardless of the color extracted as the representative color.

  FIG. 2 is a flowchart showing an example of the operation in the configuration example including the embodiment of the present invention. First, in S51, the specific color, its color range, and specified color are set by the specific color information setting unit 2. A specific example of the setting method will be described later.

  When the processing target image is given, in S52, the representative color creating unit 1 creates a color histogram from the color of each pixel of the processing target image, and extracts a representative color within a predetermined number of ranges from the color histogram. .

  When these preparations are completed, or in parallel with the representative color extraction processing in S52, the specific color replacement processing unit 3 is set for the pixels of the color within the set color range in the processing target image in S53. Replace with the specified color. Then, replaced information is added to the replaced pixel. The pixel of the color outside the set color range is left as it is.

  In S <b> 54, the color replacement unit 4 performs a replacement process with the representative color extracted by the representative color creation unit 1 in S <b> 52 on the processing target image after the processing by the specific color replacement processing unit 3. At this time, the pixel to which the replacement information is added is not replaced with the representative color. Therefore, in the image after color reduction processing output from the color replacement unit 4, the pixels in the color range centered on the specific color are replaced with the designated color by the specific color replacement processing unit 3, and the pixels of the other colors Is replaced with one of the representative colors by the color replacement unit 4.

  The reduced color image may be formed on a medium by, for example, an image forming apparatus, or may be stored or transmitted after being compressed. A known method may be applied as the compression process. For example, an image may be separated for each designated color and representative color, binary compressed, and stored or transmitted together with color information.

  Hereinafter, an example of the above-described operation will be further described using a specific example. First, the specific color information setting unit 2 sets a specific color, its color range, and a specified color. FIG. 3 is a flowchart illustrating an example of the operation of the specific color information setting unit. Here, it is assumed that a document drawn in a specific color is read and set by the image reading device, and in S61, the image of the document is read by the image reading device. In S62, a color histogram is created from the color of each pixel of the image read in S61. A color that can be a specific color is extracted in S63 from the created color histogram, and a range of colors that can be the specific color is extracted in S64. For the color that can be the specific color, the peak color of the color histogram may be extracted. Further, a color range having a preset frequency or degree of frequency (%) including the extracted peak color may be set in S64. In this example, the color range is further expanded or narrowed according to a predetermined magnification in S65 to obtain a color range to be presented to the user. The color range is set around a color that can be a specific color. In this way, the color, color range, and designated color that can be the specific color set in S63 to S65 are temporarily registered in S66. At this time, a color that can be a specific color is set as the designated color. When there are a plurality of colors that can be specific colors, a color range is set for each color and registered.

  In S67, the information registered in S66 is presented to the user, and in S68, an adjustment instruction for the specific color, color range, and designated color is received from the user. In S69, it is determined whether or not the end of the adjustment is instructed, and the adjustment by the user in S68 is continued until the end of the adjustment is instructed.

  When the adjustment end instruction is received in S69, the specific instruction, the color range, and the specified color are re-registered in S70, reflecting the adjustment instruction received from the user so far. In S71, it is determined whether or not a color that can be another unadjusted specific color has been extracted, and if it exists, the process returns to S67 to adjust the color that can be another unadjusted specific color. In addition, when there is a color that is erroneously extracted among the colors that can be the specific color, the color may be deleted from the registration of the specific color in response to a deletion instruction from the user.

  When the adjustment for the extracted specific color is completed and the specific color, the color range, and the specified color are registered, it is determined whether or not to register from another document in S72. When registering from the original, the process returns to S61 and the above-described processing is repeated. If there is no registration from another document, the registration process of the specific color, the color range, and the designated color is ended.

  An example of the operation of the specific color information setting unit 2 described above will be further described using a specific example. FIG. 4 is an explanatory diagram of an example of a document drawn in a specific color, and FIGS. 5 and 6 are explanatory diagrams of an example of an adjustment screen. In the document shown in FIG. 4, “Green” and “LOGO” are drawn in a certain color. For the sake of illustration, the colored portion is shown with diagonal lines, but here it is assumed that it is drawn in green. When this original is read by an image reading apparatus and a color histogram is created, the frequency is concentrated on green and white, and green is extracted as a color that can be a specific color. Further, the read color also has a spread due to reading error, printing unevenness, etc., and the spread is obtained as a color range, and in the operation example shown in FIG. 3, the color range is widened or reduced by a predetermined magnification. is doing. The green color extracted in this way is registered as a color that can be a specific color and a designated color together with a color range.

  Based on this registration information, for example, the adjustment screen shown in FIG. 5 is presented to the user. In FIG. 5, 11 is a color space display section, 12 is a color range, 13, 14 and 15 are color range adjustment sections, 16 is a preview section, 17 is a designated color display section, and 18 is a missing section. In this example of the adjustment screen, the color space is shown two-dimensionally on the hue-saturation axis, and is also shown one-dimensionally in the lightness axis direction, and both display colors in three dimensions. For the convenience of illustration, an attempt is made to express the color difference by changing the oblique lines, but the actual color is not expressed.

  The portion indicated by the bold line is the color range 12, and the center thereof is a color extracted as a color that can be a specific color. By moving the color range 12, the specific color as the center is adjusted.

  In the example shown in FIG. 5, a color range adjustment unit 13 for adjusting the color range in the saturation direction, a color range adjustment unit 14 for adjusting the color range in the hue direction, and a color range in the lightness direction. The color range adjustment unit 15 is provided. By changing each of these color range adjustment units 13, 14, and 15, the color range is widened or narrowed.

  Further, a preview unit 16 is provided for referring to a portion included in the currently set color range in the image read from the document, and the user determines whether the specific color or the color range is appropriate. To be used. Furthermore, the designated color and its color component are displayed on the designated color display unit 17. When the adjustment is started, a color that can be a specific color may be displayed as the designated color as it is. In this example, the designated color is adjusted by changing the value of the color component. Alternatively, the color of the color space display unit 11 may be selected.

  In the example shown in FIG. 5, the image displayed in the preview portion 16 does not have the “L” character that should exist in the missing portion 18. For example, the color may be partially different due to various factors such as a reading error of the image reading apparatus and printing unevenness of the document, and the missing portion 18 is a portion outside the set color range. If such a portion exists, the user may adjust the specific color or the color range.

  The example shown in FIG. 6 shows an example in which the color range in the saturation direction is adjusted in the example shown in FIG. When the color range adjustment unit 13 is operated to adjust the color range to expand, the color range 12 displayed on the color space display unit 11 expands in the saturation direction around the specific color. Accordingly, the preview unit 15 extracts and displays pixels of colors included in the adjusted color range. In this example, the missing “L” is included. In this example, the example of adjusting the color range in the saturation direction is shown, but of course, the color range in the hue direction and the brightness direction may be adjusted, or the specific color itself may be adjusted.

  In this way, the specific color and its color range are adjusted, the specified color displayed on the specified color display unit 17 is adjusted, and if the end button (not shown) is operated, the adjustment result up to that time is reflected. The specified specific color, color range, and designated color are registered. If such an adjustment is performed for each color drawn on the document, and if there are a plurality of documents, if each document is repeated, the specific color, the color range, and the specified color are registered. Become.

  Note that the display screens shown in FIGS. 5 and 6 are examples, and the display screen used for adjustment is not limited to this example, and adjustment may be performed using various known display forms. .

  The registration of the specific color, color range, and specified color described above is performed in advance. In the following specific example, it is assumed that green is registered as a specific color together with a color range and a designated color as in the above specific example.

  When a processing target image is given, representative colors are first extracted. FIG. 7 is an explanatory diagram of an example of the processing target image. Here, an image read by the image reading apparatus is set as a processing target image. In the example shown in FIG. 7, “G” in green, “R” in red, “B” in blue, and “K” in black are drawn in the image. Among these, “G” drawn in green is assumed to use the color drawn on the document used when registering the specific color. For convenience of illustration, the difference in color is indicated by hatching, and black is indicated by being filled.

  A representative color is extracted by a known method based on the color of each pixel of the processing target image. As an example, a color histogram may be created and a representative color may be extracted from a peak color or the like. In this example, it is assumed that five colors of green, red, blue, black, and white are extracted as representative colors. When an image read by the image reading apparatus is a processing target image, a different color is generated as a color in the color space, for example, an intermediate color exists at the boundary of each drawing figure due to a reading error of the image reading apparatus. There is a case. Even in such a case, the intermediate color of the boundary portion is not extracted because it is less frequent than the color inside the graphic, and the color inside the graphic is extracted as the representative color. For “G” drawn in green, the color used when registering the specific color is used as described above, but the specific color is extracted as a representative color due to color misalignment or the like. Not exclusively.

  When the representative color is extracted, the process target image is reduced. First, the specific color replacement processing unit 3 replaces a pixel having a color in the color range centered on the specific color set by the specific color information setting unit 2 with a specified color. FIG. 8 is an explanatory diagram of an example of an image replaced by the specific color replacement processing unit and replaced information. Among the processing target images shown in FIG. 7, the color of the pixel constituting “G” drawn in green in this example, with a color in the color range centered on the specific color set by the specific color information setting unit 2 Is replaced with a designated color registered in association with the specific color. FIG. 8A shows an image obtained by replacing the color in the color range centered on the specific color with the specified color by the specific color replacement processing unit 3. The diagonal line of “G” is changed to indicate that it is after processing. As for the intermediate color existing in the boundary portion, the pixel whose color falls within the color range is replaced with the designated color. Even if there is a difference in color due to noise or the like existing in the figure “G”, if it falls within the color range, it will be replaced with a designated single color.

  In addition, replacement information is added to the pixel replaced with the designated color. Here, for example, it is shown that the replaced information is added to the pixel of the part shown in black in FIG. The image after the replacement with the designated color and the replaced information are passed to the color replacement unit 4. The replacement of the specific color with the designated color may be performed in parallel with the representative color extraction process.

  The color replacement unit 4 performs replacement with the representative color for the image that has been replaced with the designated color by the representative color replacement processing unit 3. At this time, the pixel to which the replacement information is added is not replaced. In this specific example, the red, blue, and black graphic portions are replaced with the representative colors red, blue, and black, respectively, and the background is also replaced with white. However, the green graphic is not replaced because the specific color replacement processing unit 3 has already performed the replacement processing. Thus, for example, when a specific color is used for the processing target image, a color different from the specific color is extracted as the representative color, or the specific color is represented by the frequency of use of the color in the entire processing target image. Even if not extracted, the specific color replacement processing unit 3 replaces the specific color portion with the designated color and outputs it as it is. The intermediate color existing at the boundary portion of each graphic is replaced with either the graphic color or the background color by the replacement by the color replacement unit 4 with the representative color, and the color of the color due to noise or the like existing in each graphic and the background is changed. The difference is also replaced with a single representative color.

  FIG. 9 is an explanatory diagram of an example of an image that has been subjected to color reduction processing. The processing target image shown in FIG. 7 is replaced with the image shown in FIG. 9A by the above-described color reduction processing. The intermediate colors that existed at the boundaries of each figure disappear, and specific colors are converted to designated colors.

  When the replaced image is decomposed into each color image as shown in FIG. 9B, for example, each decomposed image can be handled as a binary image (+ color value). However, the amount of data decreases compared to the case of handling a color image as it is.

  FIG. 10 is an explanatory diagram of another example of the processing target image. In the example of the processing target image shown in FIG. 10, a yellow-green figure is drawn together with red and black figures, and the green figure is drawn smaller than the other figures. In such a processing countermeasure figure, when representative colors are extracted, red, black, yellowish green, and white may be extracted, and green may not be extracted as a representative color. In this case, if the replacement process in the representative color replacement processing unit 3 is not performed, the color replacement unit 4 replaces the green figure with yellowish green, which is one of the representative colors, and the color changes.

  In such a case, for example, if green is registered as the specific color, for example, green (designated color) can be obtained even if green is not extracted as the representative color by the replacement processing in the representative color replacement processing unit 3. ). The green color (designated color) is stored without being replaced by the color replacing unit 4. As described above, even when a representative color is not extracted or when a similar color is extracted as a representative color, the color in the color range centered on the specific color is replaced with the designated color. It will be saved even after processing. For example, for a graphic such as a logo that stores the color as it is, if the color is registered as a representative color, the color will not be changed by the color reduction process.

  FIG. 11 is an explanatory diagram of an example of a computer program, a storage medium storing the computer program, and a computer when the functions described in the embodiment of the present invention are realized by a computer program. In the figure, 21 is a program, 22 is a computer, 31 is a magneto-optical disk, 32 is an optical disk, 33 is a magnetic disk, 34 is a memory, 41 is a CPU, 42 is an internal memory, 43 is a reading unit, 44 is a hard disk, 45 is An interface 46 is a communication unit.

  You may implement | achieve by the program 21 which can be executed by a computer all or part of the function of each part demonstrated by one Embodiment of this invention mentioned above. In that case, the program 21 and the data used by the program may be stored in a computer-readable storage medium. The storage medium refers to the reading unit 43 provided in the hardware resource of the computer, causing a change state of energy such as magnetism, light, electricity, etc. according to the description content of the program, and corresponding signals. In this format, the description content of the program is transmitted to the reading unit 43. For example, there are a magneto-optical disk 31, an optical disk 32 (including a CD and a DVD), a magnetic disk 33, a memory 34 (including an IC card, a memory card, and the like). Of course, these storage media are not limited to portable types.

  The program 21 is stored in these storage media, and the program 21 is read from the computer and stored in the internal memory 42 or the hard disk 44 by, for example, mounting these storage media on the reading unit 43 or the interface 45 of the computer 22. By executing the program 21 by the CPU 41, all or part of the functions described in the above-described embodiment of the present invention is realized. Alternatively, the program 21 is transferred to the computer 22 via the communication path, and the computer 22 receives the program 21 by the communication unit 46 and stores it in the internal memory 42 or the hard disk 44, and the CPU 21 executes the program 21. May be.

  In addition, the computer 22 may be connected to various devices via an interface 45. For example, display means for displaying information, reception means for receiving information from the user, and the like may be connected. The user may adjust the specific color, the color range, and the designated color received by the specific color information setting unit 2 using these. Further, for example, an image reading apparatus is connected via the interface 45, and an image read by the image reading apparatus is registered as a processing target image and subjected to color reduction processing and stored in the hard disk 44 or the communication unit 46. You may comprise so that it may transmit outside through. Alternatively, an image forming apparatus as an output device may be connected via the interface 45 so that a reduced color image is formed by the image forming apparatus. Alternatively, the image reading apparatus and the image forming apparatus may be connected to the interface 45, and the image read by the image reading apparatus may be subjected to color reduction processing and formed by the image forming apparatus.

  Of course, it may be partially configured by hardware, or all may be configured by hardware. Or you may comprise as a program which included all or one part of the function demonstrated by one Embodiment of this invention with the other structure. For example, an apparatus including an image reading apparatus such as a copying machine or an image forming apparatus is configured as one program together with a control program, or an apparatus including an image reading apparatus such as a scanner or an apparatus including an image forming apparatus such as a printer together with a control program. You may comprise as one program. Of course, when applied to other purposes, it may be integrated with the program for that purpose.

  DESCRIPTION OF SYMBOLS 1 ... Representative color creation part, 2 ... Specific color information setting part, 3 ... Specific color replacement process part, 4 ... Color replacement part, 11 ... Color space display part, 12 ... Color range, 13, 14, 15 ... Color range adjustment , 16 ... Preview part, 17 ... Designated color display part, 18 ... Missing part, 21 ... Program, 22 ... Computer, 31 ... Magneto-optical disk, 32 ... Optical disk, 33 ... Magnetic disk, 34 ... Memory, 41 ... CPU, 42 ... Internal memory, 43 ... Reading unit, 44 ... Hard disk, 45 ... Interface, 46 ... Communication unit.

Claims (4)

  A specific color replacement processing unit that replaces a specific color in a color range designated in advance in the processing target image with a corresponding specified color, and an image region that is a replacement target by the specific color replacement processing unit in the processing target image An image processing apparatus comprising color replacement means for replacing an image area other than the representative color extracted from the processing target image.   The image processing apparatus according to claim 1, further comprising: a specific color information setting unit configured to set the specific color, a color range centered on the specific color, and the specified color.   The specific color information setting means sets the specific color from an image obtained by reading an original drawn with the color to be the specific color by an image reading means, and a color centered on the set specific color. The image processing apparatus according to claim 2, wherein a designation of a range is received.   An image processing program for causing a computer to execute the function of the image processing apparatus according to any one of claims 1 to 3.

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