JP5577783B2 - Image processing apparatus, image forming apparatus, and program - Google Patents

Description

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

  It is determined before reading out image data in the page memory whether the original of the read image data is color or monochrome, and color image data subjected to color image processing and monochrome image data subjected to monochrome image processing according to the determination result There is known an image forming apparatus that selects one of these and performs color image formation or monochrome image formation based on a determination result and selected image data (see Patent Document 1).

JP 2005-033489 A

  An object of the present invention is to provide an image processing apparatus, an image forming apparatus, and a program capable of suppressing a difference between a color determination result of a read image and an image formation result of an image forming unit.

According to the first aspect of the present invention, there is provided a first image processing means for performing color image processing on image data obtained by reading an image by a reading means, and a monochrome image for the image data obtained by reading. Second image processing means for performing the image processing, the size of the image represented by the image data obtained by the reading, the size of the recording medium on which the image is formed by the image forming means, and the reading obtained When a first determination unit that determines an image forming area of the image forming unit according to the content of image processing performed on the image data and an image represented by the read image data are divided into a plurality of images for each divided area of the image of the image forming region is used to determine whether a color or monochrome, and detecting means for detecting Ru information der showing a color-likeness of the image of the divided region color decision information, Based on the image forming area and the detection result of the detecting means, the image of the image forming area is used without using the detection result of the divided area where the image is not formed by the color image processing and the black and white image processing. Color determination information for divided areas including the image forming area, the color image processing, and the non-image forming area in which an image is not formed by the black and white image processing. a second determination means for image of the image forming region by using by multiplying the ratio of the area of the divided region of the area of the image forming area included in the divided areas to determine whether a color or monochrome, the second determination When the image is determined to be color, the image forming unit is configured to form a color image based on the image data that has been subjected to image processing by the first image processing unit. If the second determination means determines that the image is black and white, the image formation is performed so that a black and white image is formed based on the image data that has been subjected to image processing by the second image processing means. Control means for controlling the means.

According to a second aspect of the invention, in the image processing apparatus according to claim 1, wherein the color determination information, the image of the divided region is information indicating a color likeness of the image information or the divided region indicates a color or black-and-white first 1 information and second information indicating the position of the color area included in the image of the divided area in the divided area, and the second determination means is the detection result of the image forming area and the detection means. And a first determination process for determining whether each divided area is color or black and white for divided areas other than the divided areas in which an image is not formed by the color image processing and the monochrome image processing. And a second determination process for accumulating the results of the first determination process to determine whether the image in the image forming area is color or black and white. In the first determination process, the image forming area and the Kara A divided area including a non-image forming area in which an image is not formed by the image processing for black and white and the image processing for black and white is determined based on the first information and the second information. For a divided area that does not include an area other than the image forming area, it is determined whether it is color or black and white based on the first information.

According to a third aspect of the present invention, there is provided a reading unit that reads an image, a first image processing unit that performs color image processing on image data obtained by reading an image by the reading unit, and the reading unit. Second image processing means for performing monochrome image processing on the obtained image data, the size of the image represented by the read image data, and the size of the recording medium on which the image is formed by the image forming means And first determination means for determining an image forming area of the image forming means according to the content of image processing performed on the image data obtained by the reading, and the image data obtained by the reading image for each divided region when the divided into a plurality of representative images of the image forming region is used to determine whether a color or monochrome, Ru information der showing a color-likeness of the image of the divided region color Based on detection means for detecting constant information, and detection results of the divided areas where no image is formed by the color image processing and the monochrome image processing based on the image forming area and the detection result of the detection means. A division including determining whether an image in the image forming area is color or black and white without using the image forming area and the non-image forming area where the image is not formed by the color image processing and the black and white image processing for color determination information areas, the division of the area of the image forming area included in the area the divided image using by multiplying the ratio of the area of the image forming area of the region is the second to determine whether a color or monochrome When the color is determined by the determination unit and the second determination unit, a color image is formed based on the image data subjected to the image processing by the first image processing unit. The image forming unit is controlled so that when the second determining unit determines black and white, a black and white image is generated based on the image data that has been subjected to image processing by the second image processing unit. And an image processing apparatus that controls the image forming unit to be formed.

According to a fourth aspect of the present invention, there is provided an image forming unit that forms an image on a recording medium, a first image processing unit that performs color image processing on image data obtained by reading an image by a reading unit, An image is formed by the second image processing means for performing monochrome image processing on the image data obtained by reading, the size of the image represented by the image data obtained by reading, and the image forming means. A first determination unit that determines an image forming area of the image forming unit according to the size of the recording medium and the content of image processing performed on the image data obtained by the reading; image for each divided region when the divided into a plurality of representative image data that has been is employed to image the image forming area to determine whether a color or monochrome, information indicating the color likeness of the image of the divided region Detecting means for detecting an der Ru color determination information, on the basis of the image forming area and the detection result of said detecting means, image processing and the divided area where the image is not formed by the image processing of the black-and-white of the color A non-image forming area where it is determined whether the image in the image forming area is color or black and white without using the detection result of the image, and no image is formed by the image forming area, the color image processing, and the black and white image processing For the color determination information of the divided area including the above, the ratio of the area of the image forming area included in the divided area to the ratio of the area of the divided area is used to determine whether the image of the image forming area is color or black and white If the color is determined by the second determination unit and the second determination unit, the color is determined based on the image data subjected to the image processing by the first image processing unit. The image forming unit is controlled so that the first image is formed, and when the second determining unit determines that the image is black and white, the second image processing unit performs image processing on the basis of the image data. And a control unit that controls the image forming unit so that a monochrome image is formed.

According to a fifth aspect of the present invention, there is provided a reading unit for reading an image, an image forming unit for forming an image on a recording medium, and color image processing for image data obtained by reading the image by the reading unit. One image processing means, a second image processing means for performing monochrome image processing on the image data obtained by reading, the size of an image represented by the image data obtained by reading, the image The first image forming region is determined based on the size of the recording medium on which the image is formed by the forming unit and the content of image processing performed on the image data obtained by the reading. and determination means, for each divided each region when dividing the image represented by the image data obtained by reading the multiple images of the image forming region is used to determine whether a color or monochrome, divided territory Detecting means for detecting information der showing a color-likeness of the image Ru color determination information, on the basis of the detection result of said detecting means and the image forming region, the image processing and image processing of the black-and-white of the color It is determined whether the image of the image forming area is color or black and white without using the detection result of the divided area where the image is not formed by the image, and the image is formed by the image forming area and the color image processing and the black and white image processing. For the color determination information of the divided region including the non-image forming region where no image is formed, the ratio of the area of the image forming region included in the divided region to the area of the divided region is multiplied and used. a second determination unit which images to determine whether color or monochrome, wherein when it is determined that the color is the second judgment means, the image processing lines in the first image processing means The image forming unit is controlled so that a color image is formed based on the obtained image data. When the second determining unit determines black and white, the second image processing unit performs image processing. And a control unit that controls the image forming unit so that a black and white image is formed based on the image data subjected to.

According to a sixth aspect of the present invention, there is provided a first image processing means for performing color image processing on image data obtained by reading an image by a reading means on a computer, and the image data obtained by reading. Second image processing means for performing monochrome image processing, the size of the image represented by the image data obtained by reading, the size of the recording medium on which the image is formed by the image forming means, and the reading obtained In accordance with the content of the image processing performed on the image data, a first determination unit that determines an image forming area of the image forming unit and an image represented by the read image data are divided into a plurality of for each divided region when the image of the image forming region is used to determine whether a color or monochrome, and detects information der Ru color determination information indicating the color likeness of the image of the divided region Based on the output means, the image formation area and the detection result of the detection means, the image formation without using the detection result of the divided area where the image is not formed by the color image processing and the monochrome image processing. Color determination information of divided areas including whether the image in the area is color or black and white, and the image forming area, the image processing for color, and the non-image forming area where the image is not formed by the image processing for black and white the second determination means image of the divided areas the image forming region by using by multiplying the ratio of the area of the area of the image forming area included in the divided region to determine whether a color or monochrome, and the first When it is determined that the color is determined by the second determination unit, the color image is formed so that a color image is formed based on the image data subjected to the image processing by the first image processing unit. The forming unit is controlled so that when the second determining unit determines black and white, a black and white image is formed based on the image data subjected to image processing by the second image processing unit. It is a program for functioning as a control unit for controlling the image forming unit.

  According to the first aspect of the present invention, it is possible to suppress the color determination result of the read image from being different from the image formation result of the image forming unit as compared with the case where the present configuration is not provided. .

Further, according to the invention described in claim 1, as compared to the case where the present constitution is not provided, given the precision of the color determination of the image forming area.

According to the invention described in claim 2, compared to the case where the present constitution is not provided, given the precision of the color determination of the image forming area.

According to the third aspect of the present invention, it is possible to suppress the color determination result of the read image from being different from the image formation result of the image forming unit as compared with the case where the present configuration is not provided. .

According to the fourth aspect of the present invention, it is possible to suppress the color determination result of the read image from being different from the image formation result of the image forming unit as compared with the case where this configuration is not provided. .

According to the fifth aspect of the present invention, it is possible to suppress the color determination result of the read image from being different from the image formation result of the image forming unit as compared with the case where the present configuration is not provided. .

According to the sixth aspect of the present invention, it is possible to suppress the color determination result of the read image from being different from the image formation result of the image forming unit as compared with the case where the present configuration is not provided. .

1 is a diagram illustrating an example of a configuration of an image forming apparatus according to an embodiment. 1 is a diagram illustrating a functional configuration of an image forming apparatus according to an embodiment. It is a figure which shows the detailed structure of a color determination part. 6 is a flowchart showing a flow of copying processing executed in the image forming apparatus. It is a flowchart which shows the flow of the color determination process performed in a color determination part. It is a figure which shows typically an example of the determination result of an image formation area. When a document having a color image only at the positions shown on both the front and back sides is read by a mechanical reversal image reading unit to form an image, color determination is performed without using the color determination unit according to the embodiment. It is explanatory drawing explaining the color determination result and image formation result at the time of doing. Color determination without using the color determination unit according to the embodiment when a document having a color image only at the position shown on both the front and back sides is read by a double-sided simultaneous image reading unit to form an image. It is explanatory drawing explaining the color determination result and image formation result at the time of doing. FIG. 2 is a diagram illustrating a functional configuration of an image forming apparatus including a double-sided simultaneous image reading unit.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

  The printer according to the present embodiment forms an image using image data input from the outside via a communication interface (not shown) or image data obtained by reading an image of a document.

  FIG. 1 is a diagram illustrating an example of the configuration of the image forming apparatus 10.

  The image forming apparatus 10 includes a central processing unit (CPU) 11, a read only memory (ROM) 12, a random access memory (RAM) 13, a user interface (UI) 14, an image reading unit 15, an image processing unit 16, and image formation. Each of which is connected via a bus 18.

  The CPU 11 executes a program stored in the ROM 12 and controls the operation of the image forming apparatus 10. The ROM 12 stores programs executed by the CPU 11, data necessary for the processing of the CPU 11, and the like. The RAM 13 is used as a work memory.

  Note that the storage medium for storing the program executed by the CPU 11 is not limited to the ROM 12. For example, a flexible disk, a DVD disk, a magneto-optical disk, a USB (Universal Serial Bus) memory, or the like (not shown) may be used.

  The UI 14 includes, for example, a touch panel display in which a touch panel is superimposed on a display, operation buttons, and the like. Various information is displayed on the UI 14, and various information and settings are input by user operation.

  The image reading unit 15 has a function as a scanner for reading an image of a document. For example, a document placed on a platen glass (not shown) can be a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or the like. The image is read by the image sensor, or the document placed on the automatic document feeder is conveyed to the image sensor and read. Image data obtained by reading (for example, each color of RGB) is stored in the RAM 13.

  In the image reading unit 15 of the present embodiment, since the document placed on the automatic document feeder is conveyed to the image sensor and the surface of the document is read, the back side of the document is read mechanically. An automatic document reversing unit that reverses the document and re-transports it to the image sensor is also provided, and is configured to be able to read both sides of the document placed on the automatic document feeding unit. Here, the image reading unit 15 capable of reading on both sides has been described as an example, but the image reading unit 15 that reads on one side may be used.

  In the image reading unit 15, a plurality of optical sensors are provided on the transport path from the platen glass and the automatic document feeder to the image sensor, and when the document is read by the sensors, a reading target is read. The size of the original is detected. In the present embodiment, the detected size becomes the size of the reading area of the image reading unit 15.

  The image processing unit 16 receives image data input from the outside via a communication interface (not shown) or image data obtained by reading an image of a document by the image reading unit 15. The image data input to the image processing unit 16 is image data including the pixel value of each pixel constituting the image, and the image processing unit 16 performs various processing on each pixel value of the input image data. Perform image processing. The functional configuration of the image processing unit 16 will be described later.

  The image forming unit 17 is a print engine that forms an image based on the image data image-processed by the image processing unit 16, and has a Y (yellow) color from upstream to downstream along the process direction. Y image forming unit for forming an image, M image forming unit for forming an image of M (magenta) color, C image forming unit for forming an image of C (cyan) color, K image for forming an image of K (black) color The forming unit is arranged in tandem, and further includes an intermediate transfer belt, a primary transfer unit, a secondary transfer unit, and a fixing device. The Y image forming unit, the M image forming unit, the C image forming unit, and the K image forming unit are respectively a photoconductor, a charger that charges the surface of the photoconductor, and an image corresponding to the charged photoconductor. An exposure apparatus that forms an electrostatic latent image by exposure based on data, and a developing apparatus that develops by attaching toner of a color corresponding to each image forming unit on the surface of the photoreceptor on which the electrostatic latent image is formed And. Then, each toner image developed by the developing device of each image forming unit is transferred from each photoconductor to the intermediate transfer belt by the primary transfer unit provided for each image forming unit, and is superimposed. Further, the toner image on the intermediate transfer belt is electrically drawn by the secondary transfer unit and transferred to the recording paper. The toner image transferred to the recording paper is fixed on the recording paper by the fixing device.

  Here, the image forming unit using the intermediate transfer belt has been described as an example, but a toner image may be directly transferred to a recording sheet without using the intermediate transfer belt. Although the tandem type electrophotographic image forming unit is illustrated here, the image forming unit is not limited thereto, and may be, for example, an image forming unit provided with a rotary developing device. In other words, one photosensitive member, one charger, one exposure device, and a developing device that supplies toner of each color of YMCK are provided, and the electrostatic latent image based on image data for each color of YMCK is applied to the photosensitive member charged by the charger. By forming an image and developing it with toner, toner images of each color are formed in order and transferred sequentially to an intermediate transfer belt, and the toner images are transferred onto a recording sheet and fixed. In addition to the electrophotographic method, the image forming unit may be an ink jet method that performs printing while ejecting ink droplets for each color of YMCK according to image data for each color of YMCK from the recording head and transporting the recording paper. .

  FIG. 2 is a diagram illustrating a functional configuration of the image forming apparatus 10.

  As shown in FIG. 2, the image processing unit 16 includes a color determination unit 30, a color image processing unit 32, and a monochrome image processing unit 34.

  The color determination unit 30 reads an image of a document by the image reading unit 15 and forms an image of the document read by the image forming unit 17 (so-called copying). Before the image forming unit 17 forms an image, the image forming unit 17 determines whether the image in the area where the image is formed (hereinafter referred to as an image forming area) is color or monochrome. This color determination is performed in parallel with the image processing in the color image processing unit 32 and the monochrome image processing unit 34 described below. A reduction in productivity can be suppressed as compared with the case where the color determination is performed after image processing.

  The color image processing unit 32 performs color image processing on image data obtained by reading by the image reading unit 15 (hereinafter referred to as read image data). The black and white image processing unit 34 performs black and white image processing on the read image data.

  The control unit 20 is a function realized by the CPU 11 executing a program, and controls operations of the image reading unit 15, the image processing unit 16, and the image forming unit 17.

  The storage unit 24 is a storage area provided in the RAM 13, and stores image data after image processing by the color image processing unit 32 and image data after image processing by the monochrome image processing unit 34. The

  FIG. 3 is a diagram illustrating a detailed configuration of the color determination unit 30. The color determination unit 30 includes an area determination unit 40, a color determination information detection unit 42, a color determination information holding unit 44, and a color determination processing unit 46.

  The area determination unit 40 is an image forming area where an image is formed by the image forming unit 17 and a size of a divided area that is a detection unit when detecting color determination information described later (for example, α pixel × β pixel). , Expressed by the number of pixels).

  The color determination information detection unit 42 detects the color determination information for each divided area when the read image represented by the read image data is divided into a plurality of divided areas determined by the area determination unit 40.

  The color determination information is information used to determine whether the image of the image forming area is color, and the color determination information is information indicating whether the image of the divided area is color or black and white, and the image of the divided area At least one of information indicating the color likeness and position information indicating a position of the color area included in the image of the divided area in the divided area.

  When the color determination information detection unit 42 detects information indicating whether it is color or black and white, for example, if the number of color pixels equal to or greater than the threshold is included in the divided area, it is detected that the color is detected. Color determination information indicating color may be generated, and if the color pixel is less than the threshold, it may be detected that black and white is detected, and color determination information indicating black and white may be generated.

  The information indicating the color likelihood is, for example, the ratio of the area of the color area included in the image of the divided area to the area of the divided area (more specifically, the divided area having the number of color pixels included in the divided area). Information indicating the ratio of the number of pixels included), information indicating the number of color pixels included in the image of the divided region, or information indicating the saturation of the image of the divided region. There may be. Note that the information indicating the saturation may be, for example, the average value of the saturation of each pixel included in the divided region, or the saturation existing in a plurality of preset sections in a range where saturation can be obtained. It may be a histogram in which the number of each pixel in the divided area having the number is counted.

  The position information may be, for example, information indicating which of the small divided areas when the color area is further divided into a plurality of divided areas. Further, information indicating any one of left side, right side, upper side, lower side, lower left side, upper left side, upper right side, lower right side, and the entire area with reference to the center of the divided area may be used. The position information may be included in the color determination information when the information indicating color or black and white indicates color, or when the information indicating color likelihood is not 0. However, the information indicating whether color or black and white and the color likelihood are included. It is possible to include only the position information in the color determination information without including the information indicating the color determination information. For example, if a color area exists in the divided area, position information indicating the position may be detected as color determination information, and if no color pixel exists in the divided area, position information cannot be detected. Therefore, for example, information indicating a specific identifier (for example, “0” or the like) may be generated as position information.

  The color determination information holding unit 44 is a memory that holds color determination information for each divided area detected by the color determination information detection unit 42.

  Based on the image formation area information indicating the image formation area determined by the area determination unit 40 and the color determination information for each divided area held in the color determination information holding unit 44, the color determination processing unit 46 It is determined whether the image of the formation area is color or black and white, and the determination result is output to the control unit 20.

  Next, a flow of copying processing including color determination processing performed in the image forming apparatus 10 according to the present embodiment will be described.

  FIG. 4 is a flowchart showing the flow of copying processing according to this embodiment.

  In step 100, the control unit 20 displays a screen on the UI 14 and causes the user to input setting information used for the copying process from the UI 14.

  The setting information includes reading conditions when the image reading unit 15 reads a document, image forming conditions when the image forming unit 17 forms an image, designation of image processing performed on the read image data, and an operation mode of the image forming apparatus 10 The specification of etc. is included.

  The reading conditions include, for example, the resolution at which the image reading unit 15 reads a document, and designation of whether to perform double-sided reading or single-sided reading.

  The image forming conditions include the size of the recording paper on which an image is formed (hereinafter referred to as output paper size).

  The designation of image processing includes, for example, an enlargement / reduction ratio in the case of enlarging / reducing the image data obtained by reading and area designation. When the enlargement / reduction ratio is designated, the color image processing unit 32 and the black and white image processing unit 34 perform processing for enlarging / reducing the image represented by the read image data according to the designated enlargement / reduction ratio.

  The area designation includes, for example, a frame erase designation, a middle erase designation, and an extraction designation.

  When frame erasure is specified, the image corresponding to the frame-shaped area at the peripheral edge of the recording paper is erased so that a margin of the width specified by the user is formed from the outer edge of the recording paper (replaced with white) Image processing is performed on the read image data.

  When the erase is designated, the image in the range is erased (replaced with white) so that an image in a predetermined range (or designated range) is not formed from the center of the image represented by the read image data. Image processing is performed on the read image data. For example, when an image is formed by reading an image of a document with a binding margin portion such as a book open, a shadow generated in the binding margin portion is also formed. If you specify to erase, this shaded part will be erased.

  When extraction is specified, image processing is performed such that the image of the area other than the extraction area is erased (replaced with white) so that only the image of the extraction area specified in the image represented by the read image data is formed. Is performed on the read image data.

  The operation mode includes a color determination operation mode (designation indicating whether color determination is performed with priority on speed, color determination with priority on accuracy, determination with priority on color, or determination with priority on black and white).

  The input setting information is output to the control unit 20 (see also (1) in FIG. 2).

  Upon receiving the setting information, the control unit 20 outputs the setting information to the color image processing unit 32 and the monochrome image processing unit 34 (see also (2) in FIG. 2).

  In step 102, the control unit 20 outputs the reading conditions included in the setting information to the image reading unit 15, and controls so that the image of the document is read under the reading conditions (also (3) in FIG. 2). reference.). The read image data obtained by reading the document by the image reading unit 15 and information indicating the size of the reading area (original) detected by the sensor at the time of reading (hereinafter referred to as reading area information) are the color determination unit 30, It is output to the color image processing unit 32 and the monochrome image processing unit 34 (see also FIG. 2 (4)).

  When the setting information is input from the control unit 20 and the read image data and the reading area information are input from the image reading unit 15, the color image processing unit 32 starts color image processing. In addition, when the setting information is input from the control unit 20 and the read image data and the reading area information are input from the image reading unit 15, the black and white image processing unit 34 starts monochrome image processing.

  The color image processing unit 32 performs image processing in accordance with the image processing designation included in the setting information, and performs color conversion processing for a predetermined color. The color conversion process for color refers to a conversion process for converting RGB read image data into color CMYK image data.

  The black and white image processing unit 34 performs image processing in accordance with the image processing designation included in the setting information, and also performs predetermined black and white color conversion processing. The monochrome color conversion process refers to a conversion process for converting RGB read image data into monochrome CMYK color image data, for example.

  In step 104, the control unit 20 outputs setting information to the color determination unit 30 to perform color determination (see also (5) in FIG. 2). Thus, the color determination unit 30 performs the color determination process shown in FIG.

  In step 200, the area determination unit 40 determines the size of the divided area based on the setting information.

  For example, it may be determined that the size of each divided region increases as the resolution of the reading condition increases, or the size of each divided region increases as the enlargement / reduction ratio specified in the setting information increases. Good.

  Furthermore, the size of each divided area may be varied according to the area designation (frame erase, center erase, etc.). For example, the size of a divided region close to a region where an image is not formed by frame erasing or middle erasing is reduced (high accuracy), and the size of a divided region far from a region where an image is not formed is increased (low). (Accuracy).

  Further, when the accuracy (fineness) is also designated by the area designation, the size of the divided area may be determined according to the resolution and the area designation accuracy. For example, when it is specified to delete an area such as eraser with 1 mm accuracy, when the specified resolution is 600 dpi, the size is 24 pixels × 24 pixels, and when the specified resolution is 400 dpi, 16 pixels × 16 pixel size, etc.

  In addition, if the mode for determining the color with speed priority is specified as the operation mode, the size of the divided area is increased, and if the mode for determining the color with priority for accuracy is specified, the size of the divided area is set with the speed priority. It may be made smaller than the case.

  Here, the example in which the size of the divided area is determined according to the setting information has been described. However, the present invention is not limited to this, and the step 200 may be omitted without being limited to the setting information.

  In step 202, the color determination information detection unit 42 detects color determination information for each divided area when the image represented by the read image data is divided by the determined size, and stores the result in the color determination information holding unit 44. Let In this embodiment, the number of color pixels included in the divided area is detected as the color determination information.

  In step 204, the area determination unit 40 reads the reading area information input from the image reading unit 15, the setting information input from the control unit 20 (the output paper size included in the image forming conditions, and the image processing such as area specification). Content), an image forming area in which an image is formed by the image forming unit 17 is determined.

  FIG. 6 schematically shows an example of the determination result of the image forming area. Here, when the size of the reading area indicated by the reading area information is equal to the output paper size (for example, when the output paper size is designated as the same as the read original, or when the size of the reading area and the designated output paper size are The case where they are equal is included as an example. As shown in FIG. 6, when the contents of the image processing specified by the setting information include frame erasing or middle erasing, a frame erasing area where no image is formed by the image forming unit 17 with respect to the reading area. A region excluding the erased region (shaded region) is determined as an image forming region. If the size of the reading area is different from the output paper size, the frame removal area in the image represented by the read image data differs depending on the output paper size. Therefore, the image forming area is determined in consideration of the output paper size.

  In step 206, the color determination processing unit 46 selects one divided region from the divided regions including the image forming region as the target divided region, and reads the color determination information of the target divided region from the color determination information holding unit 44.

  For example, in the example shown in FIG. 6, the divided area that does not include the image forming area has the horizontal position as the X coordinate, the vertical position as the Y coordinate, and the coordinates of the upper left divided area of the reading area as (0, 0). If the position of each divided area is determined as), the divided areas having X coordinates of 0 and 9 respectively, the divided areas having Y coordinates of 0 and 5 and divided areas of coordinates (2, 5) are obtained. The color determination information of these divided areas is not read in step 206 and is not used for color determination of the image forming area.

  In step 208, the color determination processing unit 46 determines whether or not the target divided area is a boundary divided area.

  Here, the boundary divided region refers to a divided region in which the image forming region and the non-image forming region where no image is formed are included in the divided region. In the example shown in FIG. 6, in the divided area including the image forming area, each of the divided areas having the X coordinate of 1 and 4, the divided areas of the Y coordinate of 1 and 8, and the coordinates (4, 2), ( 6 and 2) is the boundary divided region. Hereinafter, a divided area that is not a boundary divided area is referred to as a non-boundary divided area.

If a negative determination is made in step 208, the process proceeds to step 212. In step 212, the color determination processing unit 46 performs monochrome determination processing for the non-boundary divided area. Here, compares the threshold value TH ₁ with a predetermined color determination information, if the color decision information threshold TH ₁ or more, the image of the object divided region is determined to be a color, there is less than the threshold value TH ₁ For example, it is determined that the image of the target divided region is black and white.

Incidentally, the threshold value TH _1, may be changed depending on the operation mode included in the setting information (color priority or monochrome priority). For example, if the color preference, so as to reduce the threshold value TH _1, when the monochrome priority, modified to increase the threshold value TH ₁ than the case of the color preference.

  On the other hand, if an affirmative determination is made in step 208, the process proceeds to step 210. In step 210, the color determination processing unit 46 performs a color / monochrome determination process for the boundary divided region.

Here, first, the ratio of the area of the image forming area to the area of the divided area in the target divided area (that is, “the number of pixels in the image forming area / the number of pixels in the divided area”, hereinafter referred to as the area ratio) is obtained. . Then, the value of the area ratio obtained by multiplying the color determination information, is compared with a threshold value TH _1. If the color determination information × area ratio of the target divided area is equal to or greater than the threshold TH ₁ , it is determined that the image of the target divided area is color, and if it is less than the threshold TH ₁ , the image of the target divided area is black and white. judge.

  In step 214, the color determination processing unit 46 accumulates the number of divided areas determined to be color and the number of divided areas determined to be black and white according to the determination result of step 210 or step 212.

  In step 216, the color determination processing unit 46 determines whether or not the target divided area is the final divided area. If a negative determination is made in step 216, the process returns to step 206 with the next divided area as the target divided area, assuming that processing has not been completed for all of the divided areas including the image forming area. If the determination in step 216 is affirmative, the process proceeds to step 218, assuming that the processing has been completed for all of the divided areas including the image forming area.

In step 218, the color determination processing unit 46 determines the color of the image in the image forming area from the accumulation result in step 214, and outputs it to the control unit 20 (see also (6) in FIG. 2). For example, if the number of divided areas determined to be color is larger than the number of divided areas determined to be black and white, it is determined that the image in the image forming area is color, and the number of divided areas determined to be color is black and white. If it is less than the determined number of divided areas, it may be determined as black and white. Further, if the ratio of the number of divided areas is determined to be a color to the number of the divided region including the image forming region threshold TH ₂ or more predetermined image in the image formation region is determined to be color, the threshold value if it is less than TH _2, it may be determined black and white. If the number of divided areas determined to be color is equal to or greater than a predetermined threshold TH ₃ , it is determined that the image in the image forming area is color, and if it is less than the threshold TH ₃ , it is determined to be black and white. May be.

  Upon receiving the image formation color determination result from the color determination processing unit 46, the control unit 20 determines whether or not the image formation color determination result is color in step 106 of FIG.

  If an affirmative determination is made in step 106, image forming color mode information for forming an image based on the image data processed by the color image processing unit 32 is output to the image forming unit 17 in step 108. In addition, the image forming conditions included in the setting information are output (see also (7) in FIG. 2). As a result, the image forming unit 17 reads the image data processed by the color image processing unit 32 from the storage unit 24, and forms an image based on the read image data under the image forming conditions of the setting information.

  If the determination in step 106 is negative, in step 110, image forming color mode information for causing the image forming unit 17 to form an image based on the image data processed by the monochrome image processing unit 34. And the image forming conditions included in the setting information (see also (7) in FIG. 2). As a result, the image forming unit 17 reads out the image data image-processed by the monochrome image processing unit 34 from the storage unit 24, and forms an image under the image forming conditions of the setting information based on the read-out image data.

  In steps 108 and 110, the control unit 20 may read image data corresponding to the color determination result from the storage unit 24 and output the image data to the image forming unit 17.

Note that the determination method of the color determination processing unit 46 is not limited to the above. For example, when the color determination information is information indicating whether the image of the divided area is color or black and white, among the divided areas including the image forming area, the number of divided areas where the color determination information indicates color is accumulated, and the color is determined. if the number of divided areas threshold TH ₄ or showing an image of the image formation area determined to color, otherwise it may be determined that the black and white.

  In the above embodiment, the example in which the color determination information of the image formation area is also determined using the color determination information of the boundary division area is described. However, the color determination of the image formation area is performed without using the color determination information of the boundary division area. You may make it perform. Further, when the operation mode is speed priority, the color determination of the image forming area may be performed without using the color determination information of the boundary divided area.

Also, among the boundary divided regions, the color determination of the image forming area without the color determination information of the boundary divided regions ratio of the number of pixels of the image formation area is the threshold value TH ₅ following a predetermined relative divided region number of pixels You may make it perform.

  If the position information is included in the color determination information, in step 210, the position of the image formation area in the boundary division area corresponds to the position indicated by the position information of the color determination information. If so, the color may be determined, and the other color may be determined as black and white. For example, in the example shown in FIG. 6, the image forming area of the boundary division area at the coordinate (1,1) is located on the lower right side. If the position information of the color determination information of the boundary division area indicates “lower right”, the boundary division area is determined to be color, and if other position information is indicated, it is determined to be black and white. .

When the color determination information includes information indicating color likelihood and position information, information indicating the color likelihood (or a value obtained by multiplying the area ratio) by the threshold value TH is used for the boundary divided region. _{If it is 1} or more and the position of the image forming area in the boundary division area corresponds to the position indicated by the position information of the color determination information, the color may be determined. In addition, when the color determination information includes information indicating the likelihood of color and position information, the information indicating whether the color is black or white indicates the color for the boundary division area, and the boundary division area If the position of the image forming area in FIG. 6 corresponds to the position indicated by the position information of the color determination information, the color may be determined.

  Further, as color determination information, information indicating whether the color is black or white and information indicating color likelihood are detected for each divided area, and information indicating color likelihood is used for boundary divided areas in step 210 using information indicating color likelihood. For the non-boundary divided region, the color may be determined in step 212 using information indicating whether it is color or black and white and accumulated in step 214.

  In the above embodiment, after reading the front side, the image reading unit 15 (hereinafter referred to as mechanical reversing type) that can read both sides of the document by mechanically inverting the document by the automatic document inverting unit and reading the back side. The image reading unit 15 is described as an example. However, the front surface image sensor and the back surface image sensor are separately provided in the document conveyance path, and both sides of the document can be read without inverting the document. The image reading unit 15 (hereinafter referred to as a double-sided simultaneous image reading unit 15) may be used.

  If color determination is performed by a method for determining color based on read image data before image processing without providing the color determination unit 30 (hereinafter referred to as a conventional color determination method for convenience), the color is determined. The determination result may be different from the image formation result.

  This will be described by comparing the case where an image is formed by reading both sides with the mechanical reversal type image reading unit 15 and the case where an image is formed by reading both sides with the double-sided simultaneous image reading unit 15. Here, an example will be described in which an original having a size slightly larger than the standard size in the sub-scanning direction is scanned on both sides.

  As described above, the image reading unit 15 is provided with a sensor in the document transport path in addition to the image sensor that reads the document. When the document is read, the size of the document to be read is read by the sensor. In the case of a document having a size slightly larger than the standard size in the sub-scanning direction (document transport direction), depending on the apparatus, it is detected as a standard size closest to the actual size and is actually read. Although the area is a little larger than the standard size, only the standard size area is used for color determination, and if the “output paper size” is specified as the same as the scanned document in the setting information, or the standard size is specified. In this case, the recording paper on which the image is formed may have a fixed size.

  As shown in FIG. 7, when a document having a color image only at positions shown on both the front and back sides is read by the mechanical reversal type image reading unit 15 to form an image, both the front and back sides are formed. Thus, the sub-scanning reading direction (conveying direction at the time of document reading) and the image forming direction (conveying direction of the recording paper) are the same. When color determination is processed at a standard size (see the color determination area in FIG. 7), the color determination result is color on the front surface and black and white on the back surface, and the image formation result is also a color image formed on the front surface. Then, a black and white image is formed on the back surface, and the color determination result matches the image formation result.

  In addition, as shown in FIG. 8, when an image is formed by reading a document having a color image only at the positions illustrated on both the front surface and the back surface with the double-sided simultaneous image reading unit 15, The sub-scanning reading direction and the image forming direction are the same, but on the back side, the sub-scanning reading direction and the image forming direction are reversed.

  Since the double-sided simultaneous type reads the back side without inverting the original, the sub-scanning reading direction on the back side is different from the mechanical reverse type. However, the mechanical reversal type image reading unit 15 is more prevalent than the double-sided simultaneous image reading unit 15, and the user is accustomed to the mechanical reversal type copying or document reading. For this reason, in the double-sided simultaneous type apparatus, when the read image data on the back side is stored in the page memory, the image forming direction is the same as that of the mechanical inversion type by reading from the reverse of the storage order. It is more important that the processing is adapted to the method familiar to the user so that the copying can be easily performed without the user being aware of the reading method of the image reading unit 15.

  For these reasons, as shown in FIG. 8, on the back side, the sub-scan reading direction and the image forming direction are reversed, and when an image is formed in a standard size, the color determination result and the image forming result are different. End up.

  Even if the system that detects the document size is configured to detect the actual document size instead of the standard size, the output paper size is specified as the standard size. In the example of the document shown in FIGS. 7 and 8, the color determination result and the image formation result are different in both the mechanical reversal method and the double-sided simultaneous method.

  Whatever reading method the image reading unit 15 uses, if the color determination of the image forming area is performed as described above so that the difference between the color determination result and the image formation result is suppressed. Good.

  Note that in the case of the image forming apparatus 10 having the double-sided simultaneous image reading unit 15, image processing is performed in parallel on the read image data on both sides, and therefore the front and back color determination units are provided. .

  As shown in FIG. 9, the image processing unit 16 of the double-sided simultaneous image forming apparatus 10 includes a front color determination unit 30a, a front color image processing unit 32a, a front black and white image processing unit 34a, and a back color determination unit. 30b, a back color image processing unit 32b, and a back monochrome image processing unit 34b. The setting information is input to each of the front and back surfaces except for the condition that the front and back surfaces are common, such as the operation mode and the output paper size.

  The setting information, the read image data on the front surface, and the read area information on the front surface are input to the color determination unit 30a. The color determination unit 30a in the table performs color determination by determining the image forming area on the surface based on the input information, similarly to the color determination unit 30 of the above embodiment.

  Setting information, back side scanned image data, and back side scanning area information are input to the back color determination unit 30b. Based on the input information, the back color determination unit 30b determines the image forming area on the back side and performs color determination in the same manner as the color determination unit 30 of the above embodiment.

  The control unit 20 receives the color determination result for the front surface and the color determination result for the back surface. The control unit 20 generates and outputs image formation color mode information corresponding to the color determination result on the front surface and the color determination result on the back surface, and outputs the image formation conditions included in the setting information. The image forming unit 17 forms front and back images according to the image forming color mode information and setting information.

  In the above description, the image processing unit 16 includes the region determination unit 40, the color determination information detection unit 42, the color determination information holding unit 44, and the color determination processing unit 46, and the image processing unit 16 performs color determination to the end. Although an example was described, it is not limited to such a form. For example, the image processing unit 16 includes an area determination unit 40, a color determination information detection unit 42, and a color determination information holding unit 44, and a program for executing the function of the color determination processing unit 46 is stored in a storage unit such as the ROM 12. The function of the color determination processing unit 46 may be executed by the CPU 11 executing the program. The same applies to the double-sided simultaneous type.

  Further, the RAM 13 may be provided with an area for the color determination information holding unit 44, and the functions of the area determination unit 40, the color determination information detection unit 42, and the color determination processing unit 46 may be realized by the CPU 11 executing a program.

  Further, the image reading unit 15 and the image forming unit 17 are not provided, and the image processing unit 16 is provided with the function of the image processing unit 16. The image forming unit includes the image reading unit 15 and the image forming unit 17. It may be connected to a device. That is, an image reading or image formation may be performed by an external device. In this case, the read image data and the reading area information are received from the reading device provided with the image reading unit 15, color determination is performed, and the image forming device provided with the image forming unit 17 responds to the color determination result. Image formation is performed based on the image data subjected to image processing and setting information.

  Similarly, the image forming unit 17 may be provided without the image forming unit 17, and the image reading unit 15 and the image processing unit 16 may be provided, and image formation may be performed by an external device. 15 may be configured as an image forming apparatus provided with the image processing unit 16 and the image forming unit 17, and image reading may be performed by an external device.

10 Image forming apparatus 11 CPU
12 ROM
13 RAM
14 UI
15 Image reading unit 16 Image processing unit 17 Image forming unit 18 Bus 20 Control unit 24 Storage unit 30 Color determination unit 30a Color determination unit 30b on the back Color determination unit 32 on the back Color image processing unit 32a Color image processing unit 32b on the back Color image processing unit 34 Monochrome image processing unit 34a Black / white image processing unit 34b Front / rear black and white image processing unit 40 Area determination unit 42 Color determination information detection unit 44 Color determination information holding unit 46 Color determination processing unit

Claims (6)

First image processing means for performing image processing for color on image data obtained by reading an image by a reading means;
Second image processing means for performing monochrome image processing on the image data obtained by the reading;
Depending on the size of the image represented by the image data obtained by reading, the size of the recording medium on which the image is formed by the image forming means, and the content of image processing performed on the image data obtained by reading First determining means for determining an image forming area of the image forming means;
Used to determine whether the image in the image forming area is color or black and white for each divided area when the image represented by the image data obtained by reading is divided into a plurality of areas. detecting means for detecting information der Ru color determination information indicating,
Based on the image forming area and the detection result of the detecting means, the image of the image forming area is not used without using the detection result of the divided area where the image is not formed by the color image processing and the black and white image processing. Color determination information for divided areas including the image forming area, the color image processing, and the non-image forming area in which an image is not formed by the black and white image processing. a second determination means for image of the image forming region by using by multiplying the ratio of the area of the divided region of the area of the image forming area included in the divided areas to determine whether a color or monochrome,
If the color is determined by the second determination unit, the image forming unit is controlled so that a color image is formed based on the image data subjected to the image processing by the first image processing unit. When the second determination unit determines that the image is black and white, the image forming unit forms a monochrome image based on the image data that has been subjected to image processing by the second image processing unit. Control means for controlling
An image processing apparatus. The color determination information includes first information which is information indicating whether the image of the divided area is color or monochrome, or information indicating the color quality of the image of the divided area, and the division of the color area included in the image of the divided area. Second information indicating a position in the region,
The second determination unit is configured to determine a divided region other than the divided region in which an image is not formed by the color image processing and the black and white image processing based on the image forming region and the detection result of the detection unit. A first determination process for determining whether each divided area is color or black and white, and a second determination for accumulating the results of the first determination process to determine whether the image in the image forming area is color or black and white In the first determination process, for the divided area including the image forming area and the non-image forming area in which an image is not formed by the color image processing and the black and white image processing, Based on the first information and the second information, it is determined whether it is color or black and white. For a divided area that does not include an area other than the image forming area, color or white is determined based on the first information. The image processing apparatus according to claim 1 determines. Reading means for reading an image;
First image processing means for performing color image processing on image data obtained by reading an image by the reading means;
Second image processing means for performing monochrome image processing on the image data obtained by the reading;
Depending on the size of the image represented by the image data obtained by reading, the size of the recording medium on which the image is formed by the image forming means, and the content of image processing performed on the image data obtained by reading First determining means for determining an image forming area of the image forming means;
Used to determine whether the image in the image forming area is color or black and white for each divided area when the image represented by the image data obtained by reading is divided into a plurality of areas. detecting means for detecting information der Ru color determination information indicating,
Based on the image forming area and the detection result of the detecting means, the image of the image forming area is not used without using the detection result of the divided area where the image is not formed by the color image processing and the black and white image processing. Color determination information for divided areas including the image forming area, the color image processing, and the non-image forming area in which an image is not formed by the black and white image processing. a second determination means for image of the image forming region by using by multiplying the ratio of the area of the divided region of the area of the image forming area included in the divided areas to determine whether a color or monochrome,
If the color is determined by the second determination unit, the image forming unit is controlled so that a color image is formed based on the image data subjected to the image processing by the first image processing unit. When the second determination unit determines that the image is black and white, the image forming unit forms a monochrome image based on the image data that has been subjected to image processing by the second image processing unit. Control means for controlling
An image processing apparatus. Image forming means for forming an image on a recording medium;
First image processing means for performing image processing for color on image data obtained by reading an image by a reading means;
Second image processing means for performing monochrome image processing on the image data obtained by the reading;
The size of the image represented by the image data obtained by reading, the size of the recording medium on which the image is formed by the image forming unit, and the contents of image processing performed on the image data obtained by reading. In response, a first determination unit that determines an image forming area of the image forming unit;
Used to determine whether the image in the image forming area is color or black and white for each divided area when the image represented by the image data obtained by reading is divided into a plurality of areas. detecting means for detecting information der Ru color determination information indicating,
Based on the image forming area and the detection result of the detecting means, the image of the image forming area is not used without using the detection result of the divided area where the image is not formed by the color image processing and the black and white image processing. Color determination information for divided areas including the image forming area, the color image processing, and the non-image forming area in which an image is not formed by the black and white image processing. a second determination means for image of the image forming region by using by multiplying the ratio of the area of the divided region of the area of the image forming area included in the divided areas to determine whether a color or monochrome,
If the color is determined by the second determination unit, the image forming unit is controlled so that a color image is formed based on the image data subjected to the image processing by the first image processing unit. When the second determination unit determines that the image is black and white, the image forming unit forms a monochrome image based on the image data that has been subjected to image processing by the second image processing unit. Control means for controlling
An image forming apparatus. Reading means for reading an image;
Image forming means for forming an image on a recording medium;
First image processing means for performing color image processing on image data obtained by reading an image by the reading means;
Second image processing means for performing monochrome image processing on the image data obtained by the reading;
The size of the image represented by the image data obtained by reading, the size of the recording medium on which the image is formed by the image forming unit, and the contents of image processing performed on the image data obtained by reading. In response, a first determination unit that determines an image forming area of the image forming unit;
Used to determine whether the image in the image forming area is color or black and white for each divided area when the image represented by the image data obtained by reading is divided into a plurality of areas. detecting means for detecting information der Ru color determination information indicating,
Based on the image forming area and the detection result of the detecting means, the image of the image forming area is not used without using the detection result of the divided area where the image is not formed by the color image processing and the black and white image processing. Color determination information for divided areas including the image forming area, the color image processing, and the non-image forming area in which an image is not formed by the black and white image processing. a second determination means for image of the image forming region by using by multiplying the ratio of the area of the divided region of the area of the image forming area included in the divided areas to determine whether a color or monochrome,
If the color is determined by the second determination unit, the image forming unit is controlled so that a color image is formed based on the image data subjected to the image processing by the first image processing unit. When the second determination unit determines that the image is black and white, the image forming unit forms a monochrome image based on the image data that has been subjected to image processing by the second image processing unit. Control means for controlling
An image forming apparatus. Computer
First image processing means for performing color image processing on image data obtained by reading an image by a reading means;
A second image processing means for performing monochrome image processing on the image data obtained by the reading;
Depending on the size of the image represented by the image data obtained by reading, the size of the recording medium on which the image is formed by the image forming means, and the content of image processing performed on the image data obtained by reading First determining means for determining an image forming area of the image forming means;
Used to determine whether the image in the image forming area is color or black and white for each divided area when the image represented by the image data obtained by reading is divided into a plurality of areas. detecting means for detecting information der Ru color determination information indicating,
Based on the image forming area and the detection result of the detecting means, the image of the image forming area is not used without using the detection result of the divided area where the image is not formed by the color image processing and the black and white image processing. Color determination information for divided areas including the image forming area, the color image processing, and the non-image forming area in which an image is not formed by the black and white image processing. second judging means for image of the image forming region by using by multiplying the ratio of the area of the divided region of the area of the image forming area included in the divided areas to determine whether a color or monochrome, and the second determination The image forming unit is configured to form a color image based on the image data subjected to the image processing by the first image processing unit when the color is determined by the unit. And when the second determination means determines that the image is monochrome, the image is so formed that a monochrome image is formed based on the image data subjected to image processing by the second image processing means. Control means for controlling the forming means;
Program to function as.

Images