JP5090969B2 - Image processing device - Google Patents

Description

  The present invention relates to an image processing apparatus for executing image processing on digital image data in a digital multi-function peripheral having functions such as a copying machine, a facsimile, a printer, and a scanner.

  2. Description of the Related Art Conventionally, with the development of a reading device using a line sensor composed of a CCD photoelectric conversion element and a toner writing device by laser irradiation, a digital copying machine that creates a copy with image data digitized from an analog copying machine has appeared. Since becoming a digital copier, compatibility with other devices that handle digital image data has increased, and not only functions as a copier, but also functions such as a facsimile function, printer function, scanner function, etc. Instead of just a digital copier, it has come to be called a digital color multifunction peripheral (MFP).

  High capacity and low cost of memory such as HDD (Hard Disk Drive), high-speed and widespread communication technology such as network, improvement of CPU (Central Processing Unit) processing capability, technology related to digital image data (compression technology, etc.) Etc.) With the evolution of technology related to MFP, the functions installed in MFP are also becoming more and more diverse. On the other hand, the way in which MFPs are used has become diverse and diverse. For example, a small MFP that is installed next to a PC in pairs and allows operators to easily use the functions of copiers, facsimiles, printers, and scanners. Medium-sized MFPs that can use functions such as sorting, punching, and stapling, departments that focus on copy-related work in a company, or companies that work in the copy-related work itself are highly productive, high-quality, and many A large functional MFP is used.

  Although MFPs have been diversified from small to large, there are functions that can be shared across classes, but there are also functions that are strongly required for each class. For example, large MFPs require post-processing of paper after plotting, such as punching, stapling, and paper folding, and electronic filing at the same time as copying operations, while small MFPs require Internet FAX (facsimile devices) and PCs (personal computers). -For high-quality faxes and personal use, high-quality image printing on dedicated paper is required. In this way, various new functions have been provided, and MFPs that handle digital image data, which is a part of digital data, have been desired to provide new functions and fuse, but MFPs that are becoming more diverse In the past, a system with a set of functions required for each class was constructed, sold, and provided to the market.

  The importance of information value in business is already recognized, and it is required not only to convey information quickly, accurately and reliably, but also to convey it in an easy-to-understand and effective manner. With the speeding up / spreading of communication technology, memory capacity increase / cost reduction / miniaturization, and high performance of PCs, new functions for efficiently handling information using digital data have been provided. The provision and integration of new functions is also desired for MFPs that handle digital image data that is part of digital data. As new functions are provided and integrated in this way, it is important for digital color multifunction peripherals (MFPs) equipped with various color image input / output devices to minimize output costs and obtain output images with little image quality degradation. It becomes.

  In order to solve this problem, in Patent Document 1, the input image data and the image area separation data generated by the image area separation means are compressed and stored, and output when the image data is expanded and output. Image processing based on image attributes and image area separation data is performed.

  Further, in Patent Document 2, a feature signal generated by performing a predetermined logical operation on the information described in the page description language based on the type, kind, and attribute of the image is generated, and the feature signal is The image processing is performed for each pixel, and image quality deterioration with respect to input image data from an external I / F device or the like can be reduced. In Patent Document 3, when an image file described in a predetermined format is interpreted and developed into image data, tag data indicating an attribute is also generated and compressed and stored in units of pixels. The reading opportunity is variably controlled. Also, in Patent Document 4, after image processing that is unified with predetermined characteristics by the first image data processing device is performed and stored in the memory device, the image output destination is output to the image data by the second image data processing device. Image processing according to the image processing unit or its processing mode is performed.

  On the other hand, a digital color multifunction peripheral (MFP) can improve the reusability of an input image and efficiently cope with a change in a user request for an image processing unit serving as an image output destination or its processing mode. When the color image data handled in the system is unified with predetermined characteristics, the definition of the color space affects the cost and the image quality. In Patent Document 5, an extended color gamut digital image is represented by a restricted color gamut digital image and one or more associated remaining images that represent the difference between the extended color gamut digital image and the restricted color gamut digital image. For normal input images, it is highly reusable and handled by converting to a digital image compatible with a standard color space with a limited color gamut for handling various types of image processing. For extended color gamut digital images that cannot be represented by the digital image data, the color information deterioration can be suppressed by leaving a difference from the limited color gamut digital image.

Japanese Patent No. 3134756 Japanese Patent No. 3368143 Japanese Patent No. 3695498 JP 2007-88783 A JP 2000-115564 A

  However, in the conventional technology as described above, in a digital color multi-function peripheral (MFP) equipped with various color image input / output devices, an output image with less image quality degradation is generated while minimizing cost increase. It is fundamental to do. In order to obtain a high-quality output image, the technique disclosed in Patent Document 1 is applied to a paper original, and the technique disclosed in Patent Document 2 is applied to an image file sent from a PC or a network. It is necessary to handle incidental information that represents the characteristics of the input image together with the image data. In that case, it is actually necessary to compress and accumulate the input image data and the image area separation data generated by the image area separation means as in Patent Document 1, but in order to suppress the deterioration of the image quality as much as possible, The image area separation data representing the characteristics of each pixel is preferably reversible, and if all the image attributes and image area separation data detected by the image area separation means are accumulated, there is a problem that the cost increases greatly. .

  On the other hand, as in Patent Document 4, in order to provide image processing suitable for various connected input / output devices, the properties of image data handled in the apparatus are unified (specified R (red), G ( When converting to a green (B) (blue) color space), the color reproduction range of the unified color space may be a problem. In particular, when dealing with various input sources, color clipping occurs when the color space is too narrow, and conversely, when it is too large, the number of gradations is reduced and the hardware scale is increased. In addition, as in Patent Document 5, even when a digital image stored in a color space having a color gamut limited by holding the extended color gamut information is changed, the extended color gamut information is held. This will cause a cost increase.

  The present invention has been made in view of the above, and includes not only an image acquired by a scanner but also an image received from an external I / F device in a digital color multifunction peripheral having a color image input / output device. An object of the present invention is to obtain a high-quality output image while minimizing cost increase when outputting image data stored and stored in the MFP by the user.

In order to solve the above-described problems and achieve the object, the invention according to claim 1 is an image reading apparatus for obtaining image data obtained by reading a document and digitizing it, and an image for printing image data after image processing on a recording sheet. and forming device, a memory device for storing the image area separation information of said image data and the image data, an external I / F device for transmitting and receiving image area separation information of said image data and the image data to an external device, the image A first image data processing device for processing image data read by a reading device ; a second image data processing device for processing image data received from the external device; and reading and processing image data stored in the memory device A third image data processing device, and a bus control device connecting the devices, the first image data processing device and the second image data processing. Location, the unified nature of the image data input from the image reading apparatus and an external device, and when the unified nature, in accordance with the image input condition, the image area separation of view containing unit to the image data co Predetermined bits of information are stored in the memory device instead of extended color information used for extending color information, and the third image data processing device is suitable for output to the image forming device and external I / F device when converting the image data of the property of the input color space, and performs image processing based on the extended color information accumulated before Symbol memory device.

The invention according to claim 2 is that the unification of the properties of the image data is conversion into a specified RGB color space, and the specified RGB color is determined according to image area separation information of the image data. without changing the nature of the space, and changes the specifications for extended color space for each of RGB planes with the image area separation information.

  The invention according to claim 3 is characterized in that the expansion of the color space uses image area separation information as upper bits of a color value.

  The invention according to claim 4 is characterized in that it includes at least a color space definition, and changes specifications relating to color space expansion for each RGB plane using image area separation information in accordance with the properties of the input color space. To do.

The invention according to claim 5, when the image data is input from the image reading apparatus, the image area separation information of said image data includes the type of at least read the document, the depending on the type of read original The specification concerning the expansion of the color space for each RGB plane using the image area separation information is changed.

In the invention according to claim 6, when the image data is an input from the external I / F device, the image area separation information of the image data includes at least a photographing condition added to the image data, and changes the specifications for extended color space for each of RGB planes with the image area separation information in accordance with the shooting conditions.

  The invention according to claim 7 further includes an I / F device that allows an operator to set a mode of whether or not to perform color expansion and color expansion specifications for each RGB plane using the image area separation information. To do.

In the image processing apparatus according to the present invention, when the first image data processing apparatus and the second image data processing apparatus unify the properties of the image data input from the image reading device or the external device, in accordance with the image input condition, accumulated in memory device instead a predetermined bit of the image area separation information picture element units in the image data co the extended color information used to extend the color information, third image performing data processing apparatus, when converting the image data of the property of the input color space suitable for output to the image forming apparatus and the external I / F device, an image processing based on the extended color information accumulated before Symbol memory device Therefore, it is possible to provide an image processing apparatus capable of converting an output image with little deterioration in image quality while minimizing cost increase in a digital color multifunction peripheral (MFP) equipped with various color image input / output devices. An effect that can be.

  Exemplary embodiments of an image processing apparatus according to the present invention will be explained below in detail with reference to the accompanying drawings.

(Embodiment)
FIG. 1 shows the overall system configuration of a digital color multifunction peripheral (MFP) according to the present invention. The digital color multifunction peripheral is hereinafter referred to as MFP. In FIG. 1, reference numeral 1 is a reading device, reference numeral 2 is a first image data processing apparatus, reference numeral 3 is a bus control apparatus, reference numeral 4 is a second image data processing apparatus, reference numeral 5 is an HDD (hard disk drive), reference numeral 6 is a CPU, 7 is a memory, 8 is a plotter I / F device, 9 is a plotter device, 10 is an operation display device, 11 is a line I / F device, 12 is an external I / F device, 13 is S.H. B. (South Bridge), 14 is a ROM, 15 is a facsimile machine, and 16 is a personal computer.

  The reading device 1 includes a line sensor composed of a CCD photoelectric conversion element, an A / D converter, and a drive circuit thereof, and digital image data of 8 bits for each of RGB from the density information of the original obtained by scanning the set original. Is generated and output. The image data processing device 2 performs a process for unifying the digital image data from the reading device 1 to a predetermined characteristic and outputs it.

  FIG. 2 shows a detailed configuration of the image data processing apparatus 1. In FIG. 2, a scanner correction processing unit 30 corrects reading unevenness or the like that occurs on the mechanism of the reading device (scanner) (such as illuminance distortion), such as shading, with respect to the digital image data from the reading device in FIG. The filter processing unit 32 corrects the MFF (Modulation Transfer Function) characteristics of the scanner and changes the frequency characteristics of the read image to make the image clearer and smoother in order to prevent moire. Basically, the image data whose characteristics are unified by the processing in the γ conversion section 31 and the color conversion section 33 is stored in the MFP, and when it is reused, it is converted into an image signal suitable for the characteristics of the output destination. Details thereof will be described later.

  The image area separation unit 35 extracts a characteristic area of the document. For example, extraction of halftone dots formed by general printing, extraction of edge portions such as characters, determination of chromatic / achromatic of the image data, determination of white background whether the background image is white, etc. In the separation, the code unit 36 decodes the image area separation signal from the image area separation unit 35 into an information amount necessary for subsequent processing in the image data processing apparatus 2 in FIG.

For example, from the 7-bit image area separation signal as shown below from the image area separation unit 35,
CH2: Character (1) / Non-character (0)
CHR: Character / (1) / Non-character (0)
HT: High line number halftone dot (1) / Non-high line number halftone dot (0)
CW: Aya (1) / Non Aya <Aya> (0)
WS: White (1) / Non-white (0)
LHT: Low line number halftone dot (1) / Non-low line number halftone dot (0)
T: tracking pattern (1) / non-tracking pattern (0)
Each state of {black character, color character, character, halftone dot character, high line number dot, low line number dot, photo, tracking pattern} is 3 bits or {black character, color character, character, non Each state of character} is decoded so that it can be expressed by 2 bits.

  The bus control device 3 is a data bus control device that exchanges various data such as image data and control commands required in the digital color multifunction peripheral, and also has a bridge function between a plurality of types of bus standards. In this embodiment, the image data processing device 2, the image data processing device 4, and the CPU 6 are connected to each other by a PCI-Express bus and the HDD 5 by an ATA bus to form an ASIC.

  The image data processing unit 4 outputs an output designated by the user with respect to digital image data whose characteristics predetermined by the image data processing device 2 are unified and incidental information (decoded image area separation signal in the present embodiment). Appropriate image processing is performed and output. Details thereof will be described later. The HDD 5 is a large-sized storage device for storing electronic data that is also used in a desktop personal computer, and mainly stores digital image data and accompanying information of the digital image data in the digital color multifunction peripheral. In this embodiment, an ATA bus connection hard disk standardized by expanding IDE is used.

  The CPU 6 is a microprocessor that controls the entire control of the digital color multifunction peripheral. In the present embodiment, an Integrated-CPU in which a + α function is added to a single CPU core that has been widespread in recent years is used. In the present embodiment, a PMC RM1100 uses a CPU integrated with a connection function with a general-purpose standard I / F and a bus connection function using a crossbar switch.

  The memory 7 stores data to be temporarily exchanged in order to absorb a speed difference when bridging between a plurality of types of bus standards and a processing speed difference of the connected components themselves. This is a volatile memory that temporarily stores programs and intermediate processing data when controlling the multifunction peripheral. Since the CPU 6 is required to perform high-speed processing, the system is activated by a boot program stored in the ROM at the normal activation, and thereafter, the processing is performed by a program developed in the memory 7 that can be accessed at high speed. In this embodiment, a DIMM that is standardized and used in a personal computer is used.

  The plotter I / F device 8 receives digital image data composed of C (cyan), M (magenta), Y (yellow), and K (black) sent via a general-purpose standard I / F integrated with the CPU 6. Then, a bus bridge process for outputting to the dedicated I / F of the plotter device 9 is performed. The general-purpose standard I / F used in the present embodiment is a PCI-Express bus. When the plotter device 9 receives the digital image data composed of CMYK, the plotter device 9 outputs the received image data to the transfer paper using an electrophotographic process using a laser beam. S. B. Reference numeral 13 denotes one of chip sets used for a personal computer, which is a general-purpose electronic device called South Bridge. A bus bridge function often used in constructing a CPU system mainly including a PCI-Express and an ISA bridge is formed as a general-purpose circuit. In this embodiment, the bus is bridged with the ROM 14. The ROM 14 is a memory for storing a program (including boot) when the CPU 6 controls the digital color multifunction peripheral.

  The operation display device 10 is a part that performs an interface between the MFP and a user. The operation display device 10 includes an LCD (liquid crystal display device) and a key switch, displays various states and operation methods of the device on the LCD, and receives a key switch input from the user. Detect. In the present embodiment, the CPU 6 is connected via a PCI-Express bus. The line I / F device 11 is a device that connects a PCI-Express bus and a telephone line. This apparatus enables the MFP to exchange various data via the telephone line.

  A FAX 15 is a normal facsimile machine that exchanges image data with the digital color multifunction peripheral via a telephone line. The external I / F device 12 is a device that connects a PCI-Express bus and an external device, and this device enables the MFP to exchange various data with the external device. In this embodiment, a network (Ethernet (registered trademark)) is used for the connection I / F. That is, the MFP is connected to the network via the external I / F device 12. The PC 16 is a so-called personal computer, and the user performs various controls and input / output of image data with respect to the MFP via application software and drivers installed in the personal computer.

  Note that the image data sent from the image data processing device 2 and the external I / F device 12 and the accompanying information such as image data and image area separation signal are all encoded in the CPU 6 and then stored in the HDD 5 to obtain the image. When processing is performed by the data processing apparatus 4 and later, the conversion processing is performed after decoding. Here, the image data (RGB) whose characteristics are unified is processed at a high compression rate by irreversible JPEG (Joint Photographic Experts Group) encoding, and the incidental information such as the image area separation signal is processed by reversible K8 encoding. By doing this, image quality degradation is minimized.

(Copy operation)
The user sets a document on the reading device 1 and inputs a setting of a desired image quality mode or the like and a copy start input to the operation display device 10. The operation display device 10 converts the information input from the user into control command data inside the device and issues it. The issued control command data is notified to the CPU 6 via the PCI-Express bus. The CPU 6 executes a copy operation process program in accordance with the copy start control command data, and sequentially performs settings and operations necessary for the copy operation. The operation process is described below in order.

  The RGB 8-bit digital image data obtained by scanning the document with the reading device 1 is converted into the above-described scanner correction processing unit 30, γ in FIG. 2 in the image data processing device 2 regardless of the set image quality mode. After passing through the conversion unit 31, the filter processing unit 32, and the color conversion unit 32, they are unified into RGB signals having predetermined characteristics such as sRGB and ROMM-RGB and sent to the bus control device 3.

  Further, the code unit 36 separates the 7-bit image area separation signal generated in the image area separation unit 35 of the image data processing device 2 according to the set image quality mode, and performs subsequent processing in the image data processing device 2. It decodes and outputs to the information necessary for

For example, a 7-bit image area separation signal output from the image area separation unit 35 as shown below is used.
CH2: Character (1) / Non-character (0)
CHR: Character / (1) / Non-character (0)
HT: High line number halftone dot (1) / Non-high line number halftone dot (0)
CW: Aya (1) / Non Aya <Aya> (0)
WS: White (1) / Non-white (0)
LHT: Low line number halftone dot (1) / Non-low line number halftone dot (0)
T: tracking pattern (1) / non-tracking pattern (0)
In the separation, the code unit 36 decodes into 2-bit attribute information (image region separation signal) as shown below according to the set image quality mode.

Text original mode: Black text, color text, text, non-character Text and photo mixed original mode: text / non-character, chromatic / achromatic Photo original mode: chromatic / achromatic, white / non-white Copy original mode: black text, Colored characters, white background, non-characters

  When the bus control device 3 receives the unified RGB image data from the image data processing device 2 and the attribute information (image area separation signal) having different attributes according to the set image mode, the bus control device 3 encodes it via the CPU 6 and then stores it in the memory. 7. Accumulate in HDD5. Next, the RGB image data and the attribute information for each pixel stored in the memory 7 and the HDD 5 are decoded by the CPU 6 and then sent to the image data processing device 4 through the bus control device 3. Based on the received RGB image data and attribute information for each pixel, the image data processing device 4 converts the image data into CMYK image data for plotter output and outputs it. When the bus control device 3 receives the CMYK image data from the image data processing device 4, it stores it in the memory 7 via the CPU 6. Next, the CMYK image data stored in the memory 7 is sent to the plotter device 9 via the CPU 6 and the plotter I / F device 8. The plotter device 9 outputs the received CMYK image data to transfer paper, and a copy of the document is generated.

  Here, FIG. 3 shows a processing block diagram of the image data processing device 4, and the operation at this time will be described. The filter processing unit 50 corrects the sharpness of the unified RGB image data so that the reproducibility when output to the plotter device 9 is improved. Specifically, sharpening / smoothing processing is performed according to the attribute information (image region separation signal) decoded according to the set image quality mode. For example, in the character original mode, sharpening processing is performed to make the characters clear / clear, and in the photo mode, smoothing processing is performed to smoothly express gradation.

  When the color conversion unit 51 receives the unified RGB data of 8 bits each, it converts them into 8 bits each of C (cyan), M (magenta), Y (yellow), and K (black) which are color spaces for the plotter device. . Even at this time. Optimal color adjustment is performed according to the attribute information (image area separation signal) decoded according to the set image quality mode information. The scaling processing unit 52 converts the size (resolution) of the CMYK image data according to the reproduction performance of the plotter device 9. In the present embodiment, since the performance (recording density) of the plotter device 9 is 600 dpi output, no particular conversion is performed. When the gradation processing unit 53 receives 8 bits for each of CMYK, it performs gradation number conversion processing according to the gradation processing capability of the plotter device 9. In this embodiment, for example, conversion into 2 bits for each CMYK is performed using an error diffusion method which is one of pseudo halftone processing.

(Facsimile transmission operation)
The user sets a document on the reading device 1 and performs setting of a desired mode and the like and input of fax start on the operation display device 10. The operation display device 10 converts the information input from the user into control command data inside the device and issues it. The issued control command data is notified to the CPU 6 via the PCI-Express bus. The CPU 6 executes a fax transmission operation process program in accordance with the control command data for starting fax transmission, and sequentially performs settings and operations necessary for the fax transmission operation. The operation process is described below in order.

  RGB 8-bit digital image data obtained by scanning a document with the reading device 1 is converted into RGB values unified with predetermined characteristics by the image data processing device 2 and sent to the bus control device 3. When receiving the RGB image data from the image data processing device 2, the bus control device 3 accumulates it in the memory 7 via the CPU 6. Next, the unified RGB image data stored in the memory 7 is sent to the image data processing device 4 via the CPU 6 and the bus control device 3. The image data processing device 4 converts the received unified RGB image data into monochrome binary image data for fax transmission and outputs it. When the bus control device 3 receives the monochrome binary image data from the image data processing device 4, it stores it in the memory 7 via the CPU 6. Next, the monochrome binary image data stored in the memory 7 is sent to the line I / F device 11 via the CPU 6. The line I / F device 11 transmits the received monochrome binary image data to the FAX 15 connected via the line.

(Scanner delivery operation)
The user sets a document on the reading device 1 and performs setting of a desired mode and the like and input of scanner distribution start on the operation display device 10. The operation display device 10 converts the information input from the user into control command data inside the device and issues it. The issued control command data is notified to the CPU 6 via the PCI-Express bus. The CPU 6 executes a scanner distribution operation process program in accordance with the scanner distribution start control command data, and the scanner sequentially performs settings and operations necessary for the distribution operation. The operation process is described below in order.

  RGB 8-bit digital image data obtained by scanning a document with the reading device 1 is converted into RGB values unified with predetermined characteristics by the image data processing device 2 and sent to the bus control device 3. When the bus control device 3 receives the unified RGB image data from the image data processing device 2, the bus control device 3 stores it in the memory 7 via the CPU 6. Next, the RGB image data stored in the memory 7 is sent to the image data processing device 4 via the CPU 6 and the bus control device 3. The image data processing device 4 converts the received RGB image data into image data for scanner distribution such as sRGB and outputs it. When the bus control device 3 receives image data from the image data processing device 4 such as RGB multi-value, gray scale, monochrome binary, etc., the bus control device 3 stores it in the memory 7 via the CPU 6. Next, the image data stored in the memory 7 is sent to the external I / F device 12 via the CPU 6. The external I / F device 12 transmits the received image data to the PC 16 connected via the network.

  Next, in the present embodiment, an operation in a case where image data obtained by scanning a document is accumulated and saved in the MFP, and then the accumulated and saved image data is reused will be described.

(Copy operation + Accumulation / save operation to HDD)
The user sets a document on the reading device 1 and performs setting of a desired image quality mode and the like and input of copy start on the operation display device 10. The operation display device 10 converts the information input from the user into control command data inside the device and issues it. The issued control command data is notified to the CPU 6 via the PCI-Express bus. The CPU 6 executes a copy operation process program in accordance with the copy start control command data, and sequentially performs settings and operations necessary for the copy operation. The operation process is described below in order.

  The RGB 8-bit digital image data obtained by scanning the document with the reading device 1 is converted into the above-described scanner correction processing unit 30, γ in FIG. 2 in the image data processing device 2 regardless of the set image quality mode. Through the conversion unit 31, the filter processing unit 32, and the color conversion unit 323, the signals are unified into RGB signals having predetermined characteristics such as sRGB and ROMM-RGB and sent to the bus control device 3.

  The scanner correction processing unit 30 corrects reading unevenness or the like generated on the mechanism of the reading device (scanner) (such as illuminance distortion), such as shading, with respect to the digital image data from the reading device 1 of FIG. The γ conversion unit 31 converts the γ characteristic of the RGB image data received from the reading device 1 so as to have a predetermined characteristic (for example, 1 / 2.sup.2). The filter processing unit 32 unifies the sharpness of the RGB image data to a predetermined characteristic. For example, when the reference chart is scanned, conversion is performed so that the MTF characteristic value predetermined for each set image quality mode is obtained for each number of lines. At that time, processing is performed using parameters based on the image area separation signal generated in the image area separation unit 35. The color conversion unit 33 converts RGB image data values having predetermined characteristics such as sRGB and opRGB. The scaling processing unit 34 unifies the size (resolution) of the RGB image data to a predetermined characteristic. In the present embodiment, for example, the size (resolution) is converted to 600 dpi.

  Further, the code unit 36 separates the 7-bit image area separation signal generated in the image area separation unit 35 of the image data processing device 2 according to the set image quality mode, and performs subsequent processing in the image data processing device 2. It decodes and outputs to the information necessary for

For example, a 7-bit image area separation signal output from the image area separation unit 35 as shown below is used.
CH2: Character (1) / Non-character (0)
CHR: Character / (1) / Non-character (0)
HT: High line number halftone dot (1) / Non-high line number halftone dot (0)
CW: Aya (1) / Non Aya <Aya> (0)
WS: White (1) / Non-white (0)
LHT: Low line number halftone dot (1) / Non-low line number halftone dot (0)
T: tracking pattern (1) / non-tracking pattern (0)
In the separation, the code unit 36 decodes into 2-bit attribute information (image region separation signal) as shown below according to the set image quality mode.

Text manuscript mode: Black text, color text, text, non-character text photo mixed manuscript mode: text / non-character, chromatic / achromatic photo manuscript mode: chromatic / achromatic, white / non-white copy manuscript mode: black text, Colored characters, white background, non-characters

  When the bus control device 3 receives the unified RGB image data from the image data processing device 2 and attribute information (image area separation signal) having different attributes according to the set image mode, the bus control device 3 encodes it via the CPU 6, Accumulate in memory 7.

  The unified RGB image data stored in the memory 7 is transmitted to the HDD 5 via the CPU 6 and the bus control device 3, and is stored and stored together with image input conditions (in this case, scanner input, image quality mode, etc.) in the HDD 5. . After that, as described above, the unified RGB image data in the memory 7 is suitable for the plotter device 9 by the image data processing device 4 interpreting the scanner read image and the image quality mode set at the time of input. After being converted to an output signal, it is output to the plotter device 9 and a copy of the document is generated.

  Here, FIG. 3 shows a processing block diagram of the image data processing device 4, and the operation at this time will be described. The filter processing unit 50 corrects the sharpness of the unified RGB image data so that the reproducibility when output to the plotter device 9 is improved. Specifically, sharpening / smoothing processing is performed in accordance with the attribute information (image area separation signal) decoded according to the set image quality mode. For example, in the character original mode, sharpening processing is performed to make the characters clear / clear, and in the photo mode, smoothing processing is performed to smoothly express gradation.

  When the color converter 51 receives the unified RGB data of 8 bits each, the color converter 51 converts it to 8 bits of CMYK which is a color space for the plotter device. Also at this time, the optimum color adjustment is performed according to the attribute information (image area separation signal) decoded according to the set image quality mode information. The scaling processing unit (52) converts the size (resolution) of the CMYK image data according to the reproduction performance of the plotter device 9. In the present embodiment, since the performance of the plotter device 9 is 600 dpi output, no particular conversion is performed. When the gradation processing unit 53 receives 8 bits for each of CMYK, it performs gradation number conversion processing according to the gradation processing capability of the plotter device 9.

  As another operation at the time of image storage, the CPU 6 can detect the usage rate of the memory 7 and the HDD 5 and can encode and store the decoded attribute information after the change. For example, when an image is input in a state where the usage rate of the HDD 5 exceeds a specified value, the CPU 6 discards a part of the attribute information (image area separation signal) from the separation decoding unit 36 (for example, the lower bit) All pixels are set to 0) and then encoded and stored. When operating under this condition, for example, it is interpreted as attribute information (image area separation signal) as shown below according to the set image quality mode.

(Printer operation + Accumulation / saving operation to HDD)
The user operates DTP (Desk Top Publishing) application software on the PC 16 to create and edit various texts and graphics, and instructs setting of a desired printer output mode and printing start. The PC 16 converts a created / edited document or figure into information such as a command or data described in a page description language (PDL), and then translates the PDL data and converts it into raster image data. (RIP) is performed and sent to the CPU 6 via the external I / F device 12.

  In the present embodiment, at the time of raster image processing (RIP), conversion to unified RGB image data having predetermined characteristics is performed, and at the same time, 4-bit attribute information as shown below is also generated.

CHR: Character / line drawing (1) / Non-character / line drawing (0)
CW: Aya (1) / Non Aya <Aya> (0)
WS: White (1) / Non-white (0)
H: Saturated color (1) / Unsaturated color (0)

  Further, according to the set printer output mode, it is decoded into 2-bit attribute information as shown below, and then sent to the CPU 6 via the external I / F device 12.

General document output: achromatic colors other than images, chromatic colors other than images, images, white background Graphic output: achromatic colors, chromatic colors, white background, saturated colors Photo image output: white background / non-white background

  When the CPU 6 receives attribute information having different attributes in accordance with the unified RGB image data from the image data processing device 2 and the set image output mode, the CPU 6 encodes it via the CPU 6 and stores it in the memory 7. The unified RGB image data stored in the memory 7 is transmitted to the HDD 5 via the CPU 6 and the bus control device 3, and is stored and stored in the HDD 5 together with image input conditions (in this case, printer output, image output mode, etc.). The

  After that, as described above, the unified RGB image data in the memory 7 is suitable for the plotter device 9 by the image data processing device 4 interpreting that it is a printer output image and the image output mode set at the time of input. After being converted to an output signal, it is output to the plotter device 9 and a printer output image is generated.

  When the color converter 51 receives the unified RGB data of 8 bits each, it converts it into 8 bits of CMYK which is the color space for the plotter device 9. Also at this time, the optimum color adjustment is performed according to the decoded attribute information in accordance with the set image quality mode information. The scaling processing unit 52 converts the size (resolution) of the CMYK image data according to the reproduction performance of the plotter device 9. In this embodiment, since the performance of the plotter 9 is 600 dpi output, no particular conversion is performed. When the gradation processing unit 53 receives 8 bits for each of CMYK, the gradation processing unit 53 performs a gradation number conversion process optimum for the attribute information decoded according to the gradation processing capability of the plotter device 9 and the set image quality mode information. As another operation at the time of image storage, the CPU 6 can detect the usage rate of the memory 7 and the HDD 5 and can encode and store the decoded attribute information after the change.

(Facsimile transmission operation)
Next, an operation for reusing image data stored and saved in the HDD 5 will be described. The user performs setting of a desired mode and the like and input of facsimile transmission start to the operation display device 10 for the image data stored in the HDD 5 when the copying operation is performed earlier. The operation display device 10 converts the information input from the user into control command data inside the device and issues it. The issued control command data is notified to the CPU 6 via the PCI-Express bus. The CPU 6 executes a facsimile transmission operation process program in accordance with the control command data for starting facsimile transmission, and sequentially performs settings and operations necessary for the facsimile transmission operation. The operation process is described below in order.

  The bus control device 3 outputs the RGB image data stored in the HDD 5 to the memory 7 via the CPU 6. After that, as described above, the RGB image data in the memory 7 is output to the line I / F device 11 via the image data processing device 4 to perform facsimile transmission.

  The operation at this time will be described in order with reference to the processing block diagram of the image data processing device 4 shown in FIG. The filter processing unit 50 corrects the sharpness of the RGB image data so that the reproducibility in the case of facsimile transmission is improved. Specifically, sharpening / smoothing processing is performed according to desired mode information. For example, in the character mode, sharpening processing is performed to make the characters clear / clear, and in the photo mode, smoothing processing is performed to smoothly express gradation. When the color conversion unit 51 receives 8-bit RGB data, the FAX device 15 converts the data into a general monochrome (monochrome) 8-bit. The scaling processing unit 52 converts the size (resolution) of the monochrome image data into the size (resolution) transmitted / received by the FAX apparatus 15. In the present embodiment, main scanning is converted to 200 dpi × sub-scanning: 100 dpi. When the gradation processing unit 53 receives monochrome 8 bits, it performs gradation number conversion processing according to the gradation processing capability transmitted / received by the FAX apparatus 15. In the present embodiment, for example, the number of gradations is converted into a binary value using an error diffusion method which is one of pseudo halftone processes.

(Scanner delivery operation)
The user performs setting of a desired mode and the like and input of scanner distribution start to the operation display device 10 for the image data stored in the HDD 5 when the copying operation is performed earlier. The operation display device 10 converts the information input from the user into control command data inside the device and issues it. The issued control command data is notified to the CPU 6 via the PCI-Express bus. The CPU 6 executes a scanner distribution operation process program in accordance with the scanner distribution start control command data, and sequentially performs settings and operations necessary for the scanner distribution operation. The operation process is described below in order.

  The bus control device 3 outputs the RGB image data stored in the HDD 5 to the memory 7 via the CPU 6. Thereafter, as described above, the RGB image data in the memory 7 is output to the external I / F device 11 via the image data processing device 4 to perform scanner distribution.

  The operation at this time will be described in order with reference to the processing block diagram of the image data processing device 4 shown in FIG. The filter processing unit 50 corrects the sharpness of the RGB image data so as to improve reproducibility when the scanner is distributed. Specifically, sharpening / smoothing processing is performed according to desired mode information. For example, in the character mode, sharpening processing is performed to make the characters clear / clear, and in the photo mode, smoothing processing is performed to smoothly express gradation. When the color converter 51 receives RGB 8-bit data, it converts it into a designated color space. In this embodiment, each color is converted into 8 bits in the sRGB color space which is common in scanner distribution. The scaling processing unit 52 converts the size (resolution) of the sRGB image data into the size (resolution) transmitted / received by the designated scanner delivery. In this embodiment, the main scanning is converted to 200 dpi × sub-scanning: 200 dpi. The gradation processing unit 53 performs gradation number conversion processing according to the gradation processing capability transmitted / received by the designated scanner distribution. In this embodiment, it is assumed that 160,000 colors of 8 bits each for RGB are designated, and gradation processing is not particularly performed.

  From these, when the output destination different from the input destination is desired for the data stored and saved in the digital color multifunction peripheral (MFP), it is normal operation (operation when the output destination is designated from the beginning). The output destination can be changed without changing the image quality, and reusability is remarkably improved.

(Color conversion processing)
Next, the operation for extending the unified RGB color space, which is a feature of the present invention, will be described. In FIG. 2, the image data processing device 2 performs a process for unifying the digital image data from the reading device 1 to a predetermined characteristic and outputs the digital image data. Specifically, the relationship between the characteristics (1931CIE XYZ) shown in Table 1 is defined as follows, for example, as an average display by the processing in the γ converter 31 and the color converter 33. ) Is converted into RGB image data such as sRGB.

r = (R / 255) ^2.2
g = (G / 255) ^2.2
b = (B / 255) ^2.2 (1)

X = 0.4124 × r + 0.3576 × g + 0.1805 × b
Y = 0.2126 * r + 0.7152 * g + 0.0722 * b
Z = 0.0193 * r + 0.1192 * g + 0.9505 * b (2)

  Actually, the color conversion unit 33 can perform conversion from scanner RGB, which is a device signal γ-converted by the γ conversion unit 31, to sRGB by performing three-dimensional LUT conversion. A memory map interpolation method that has been widely used in the past is used as a conversion algorithm by a three-dimensional LUT. Three-dimensional memory map interpolation is performed on the input u_8-bit image data (InR, InG, InB).

  The memory map interpolation method divides the three-dimensional input color space into a plurality of unit cubes, further divides each divided unit cube into six tetrahedrons sharing the symmetry axis, and performs linear operation for each unit cube. Find the output value. In the linear calculation, data of division boundary points (= grid points) are used as parameters (grid point parameters). The actual processing procedure is as follows (the same processing is executed for each output version). In this three-dimensional memory map interpolation, there are eight divisions. As for the length of one side of the unit cube, first, when the input data is X (x, y, z), a unit cube containing the coordinates X is selected. Here, X (x, y, z) = (InR, InG, InB).

  The lower coordinates (Δx, Δy, Δz) of the coordinate P in the selected unit cube are obtained, the unit tetrahedron is selected by comparing the lower coordinates, the linear interpolation is performed for each unit tetrahedron, and the coordinates P The output value Pout at is obtained. Pout is an integer value obtained by multiplying the entire expression by the length of one side of the unit cube.

  P0 to P7 in FIG. 4 are grid point output values (here, corresponding to sRGB values for the γ-converted scanner RGB), and the interpolation coefficients K0, K1, K2, and K3 are the magnitude relationships of Δx, Δy, and Δz, and the above-described relationship. It is determined according to the separation signal. FIG. 5 shows tetrahedrons that are stretched on the interpolation tetrahedron by lattice points used for interpolation, and Table 2 shows a rule for determining a common interpolation coefficient for each separated signal.

  Finally, based on the output values on the preset vertices of the four points of the selected tetrahedron and the position (distance from each vertex) in the input tetrahedron, linear interpolation is performed by the following formula: To be implemented.

pout_r = K0_R × Δx + K1_R × Δy + K2_R × Δz + K3_R << 5
pout_g = K0_G × Δx + K1_G × Δy + K2_G × Δz + K3_G << 5
pout_b = K0_B x Δx + K1_B x Δy + K2_B x Δz + K3_B << 5 (3)

  The calculated three-dimensional LUT output is linearly normalized using the slope / intercept according to the following formula (see FIG. 6). If the unified RGB color space is not expanded, if the normalized data is negative or exceeds 255 (8 bits), it is clipped to 0 or 255 here. Sent to.

hokan_r = (pout_r * lutslope) >> 12-lintc
hokan_g = (pout_g * lutslope) >> 12-lintc
hokan_b = (pout_b * lutslope) >> 12-lintc (4)

  It is also possible to change the expansion range for each output plane of the three-dimensional LUT conversion. In this case, as shown below, the slope and intercept can be set for each output plane.

hokan_r = (pout_r * lutslope_R) >> 12-lintc_R
hokan_g = (pout_g * lutslope_G) >> 12-lintc_G
hokan_b = (pout_b * lutslope_B) >> 12-lintc_B (5)

  As described above, even if the input / output is set to 8 bits in the three-dimensional LUT conversion, an 8-bit grid point output value before normalization (in this case, the γ-converted scanner RGB is assumed, assuming a value exceeding 0 to 255 in advance. If it is set (corresponding to sRGB values), it is possible to cope with the expansion of the color space. Further, in the three-dimensional LUT conversion, the γ-converted scanner RGB set as an input is used as unsigned_8 bit (0 to 255) image data (InR, InG, InB), and sRGB set as a grid point output value (this embodiment) If the unified RGB color space in the form) is set in advance as signed_10 bits (−511 to 510), the above-described normalization using the slope and intercept becomes unnecessary.

  Note that the color conversion method in the color conversion unit 33 is not limited to the three-dimensional LUT conversion, and a general masking operation may be used. Regarding the normalization (clipping) of the color correction result, when the unified RGB color space is not expanded even in the masking operation, or when the normalized data is negative or exceeds 255 (8 bits) When expanding to 0 or 255, it is sent to the next processing block as it is. In the image area separation unit 35, the characteristic area of the original document described above is extracted, and in the separation, the code unit 36 converts the image area separation signal from the image area separation unit 35 into an information amount necessary for subsequent processing. Decode and output.

When the unified RGB color space is not expanded, as described above, from the 7-bit image area separation signal as shown below from the image area separation unit 35,
CH2: Character (1) / Non-character (0)
CHR: Character / (1) / Non-character (0)
HT: High line number halftone dot (1) / Non-high line number halftone dot (0)
CW: Aya (1) / Non Aya <Aya> (0)
WS: White (1) / Non-white (0)
LHT: Low line number halftone dot (1) / Non-low line number halftone dot (0)
Each state of {black character, color character, character, halftone dot character, high line number dot, low line number dot, photo, tracking pattern} is 3 bits or {black character, color character, character, non Each state of character} is decoded so that it can be expressed by 2 bits.

  When the unified RGB color space is extended, for example, the attribute information (image area separation signal) is discarded according to the set image quality mode and used for extending the color information (here, sRGB values). To do. When operating under this condition, for example, 2-bit attribute information is defined and decoded as follows according to the set image quality mode and document type.

Attribute bit 1 Attribute bit 2
-Text manuscript mode: Black text / color text, text / non-character / text photo mixed manuscript mode: text / non-character, chromatic / achromatic / print photo manuscript mode: R component extension (signed_9bit), B component extension (Unsigned_9bit)
・ Copy manuscript mode: Black text / color text, white background, non-text, photographic paper photo manuscript mode: R component expansion (signed_9bit), B component expansion (unsigned_9bit)
-IJ output manuscript mode: R component extension (signed_9bit), G component extension (unsigned_9bit)

  Here, since the required image quality and quality degradation items can be predicted in advance according to the set image quality mode and document type, the attribute bits are assigned as described above. When the original is a photographic paper photograph, the vivid blue-green (cyan) input color is expected to exceed the color gamut of the unified color space (sRGB), so it is used as an extension bit of the unified color space (sRGB) To do.

  At that time, for example, when the B component is expanded, the B value is expected to exceed 1 (255). Therefore, by using one of the attribute bits as the most significant bit of the B component, Color components from 0 to 511 can be accumulated. In particular, the most significant bit is used because the attribute bit information is stored in memory with lossless compression or compression at a lower compression rate than the image data, so the color difference with respect to the entire document can be reduced. Even when irreversible compression is performed on stored image data, false colors can be suppressed. Similarly, when the R component is expanded, the R value is expected to be less than 0. Therefore, by using one of the attribute bits as a sign bit of the R component, the R value is a color from −256 to 255. The component can be accumulated.

  In the IJ output manuscript mode, the color reproduction range of the inkjet printer and photographic paper is different, so the color components to be expanded (including polarity) are also different. The operator can also set from the operation display device 10 or the external I / F device 11 in FIG.

  The bus control device 3 is a data bus control device that exchanges various data such as image data and control commands required in the digital color multifunction peripheral, and also has a bridge function between a plurality of types of bus standards. In this embodiment, the image data processing device 2, the image data processing device 4, and the CPU 6 are connected to each other by a PCI-Express bus and the HDD 5 by an ATA bus to form an ASIC.

  The image data processing unit 4 outputs the digital image data and the accompanying information (decoded attribute information in this embodiment) whose characteristics predetermined by the image data processing device 2 are unified to an output destination designated by the user. Appropriate image processing is performed and output.

  Next, processing for input image data from the external I / F device 12 will be described. The basic processing content is the same as that of the scanner image, but in the case of input image data from the external I / F device 12 or the like, the CPU 6 performs processing for unifying the predetermined characteristics.

  Specifically, referring to a color profile that is a part of incidental information of input image data, if the color space of the input image data is different from the above sRGB, conversion is performed according to the definition formula (through 1931 CIE XYZ). Will be. For example, when the unified RGB color space is extended, the attribute information depends on the color space defined by the color profile that is a part of the incidental information of the input image data or the shooting conditions defined by the EXIF standard. The (image area separation signal) is discarded and used for extending color information (here, sRGB values).

  Regarding the decoding of the attribute information, the movement of the image quality mode for the scanner input image described above is supplementary information of the input image data from the external I / F device or the like (defined by the color space defined by the color profile or the EXIF standard). The operation is the same as that of the code unit 36 in the separation, instead of the one set according to the shooting conditions.

  FIG. 7 is a block diagram showing the hardware configuration of such a multifunction machine. As shown in the figure, the MFP 300 has a configuration in which the controller 10 and an engine unit (Engine) 360 are connected by a PCI (Peripheral Component Interconnect) bus. The controller 310 is a controller that controls the entire MFP, drawing, communication, and input from an operation unit (not shown). The engine unit 360 is a printer engine that can be connected to a PCI bus, and is, for example, a monochrome plotter, a 1-drum color plotter, a 4-drum color plotter, a scanner, or a fax unit. The engine unit 360 includes an image processing part such as error diffusion and gamma conversion in addition to a so-called engine part such as a plotter.

  The controller 310 includes a CPU 311, a north bridge (NB) 313, a system memory (MEM-P) 312, a south bridge (SB) 314, a local memory (MEM-C) 317, and an ASIC (Application Specific Integrated Circuit). 316 and a hard disk drive (HDD) 318, and the north bridge (NB) 313 and the ASIC 316 are connected by an AGP (Accelerated Graphics Port) bus 315. The MEM-P 312 further includes a ROM (Read Only Memory) 312a and a RAM (Random Access Memory) 312b.

  The CPU 311 performs overall control of the multifunction peripheral 300, has a chip set including the NB 313, the MEM-P 312 and the SB 314, and is connected to other devices via this chip set.

  The NB 313 is a bridge for connecting the CPU 311 to the MEM-P 312, SB 314, and AGP 315, and includes a memory controller that controls reading and writing to the MEM-P 312, a PCI master, and an AGP target.

  The MEM-P 312 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a memory for drawing printers, and the like, and includes a ROM 312a and a RAM 312b. The ROM 312a is a read-only memory used as a memory for storing programs and data, and the RAM 312b is a writable and readable memory used as a program and data development memory, a printer drawing memory, and the like.

  The SB 314 is a bridge for connecting the NB 313 to a PCI device and peripheral devices. The SB 314 is connected to the NB 313 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

  The ASIC 316 is an IC (Integrated Circuit) for image processing having hardware elements for image processing, and has a role of a bridge for connecting the AGP 315, the PCI bus, the HDD 318, and the MEM-C 317. The ASIC 316 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 316, a memory controller that controls the MEM-C 317, and a plurality of DMACs (Direct Memory) that rotate image data using hardware logic. Access Controller) and a PCI unit that performs data transfer between the engine unit 60 via the PCI bus. The ASIC 316 is connected to an FCU (Fax Control Unit) 330, a USB (Universal Serial Bus) 40, and an IEEE 1394 (The Institute of Electrical and Electronics Engineers 1394) interface 350 via a PCI bus.

  A MEM-C 317 is a local memory used as a copy image buffer and a code buffer, and an HDD (Hard Disk Drive) 318 is a storage for storing image data, programs, font data, and forms. It is.

  The AGP 315 is a bus interface for a graphics accelerator card that has been proposed to speed up graphics processing, and speeds up the graphics accelerator card by directly accessing the MEM-P 312 with high throughput. .

  Therefore, as described above, according to the embodiment of the present invention, the following effects are listed. First, an image reading device that reads a document and obtains electronic image data, a plotter device 9 that prints image data on transfer paper, an HDD 5 that stores image data and incidental information of the image data, an external device, and an image An external I / F device that transmits and receives data and incidental information of image data, an image data processing device 2 that processes image data from the image reading device, and an image data processing device 4 that processes image data from the external device And an image data processing device that processes image data from the HDD 5 and a bus control device 3 that connects the devices described above, in which the image data processing device 2 and the image data processing device 4 are connected to the image reading device. Image data input from an external device or the same, and when unifying the properties, The color information is expanded and stored in the HDD 5 using pixel area image area separation information stored together with the data, and the image data processing device 4 is suitable for output to the plotter device 9 and the external I / F device 12. Since the image processing based on the supplementary information is performed when converting into the image data of the property, in the digital color multi-function peripheral (MFP) equipped with various color image input / output devices, the cost increase is suppressed as much as possible and the image quality deterioration is reduced. It is possible to provide an image processing apparatus capable of converting into a small number of output images.

  Second, in the first aspect, the unification of the properties of the input image data is performed by converting each of the RGB planes using the image area separation information according to the incidental information of the input image data by converting the input image data into a specified RGB color space. Because the specifications for color space expansion with respect to have been changed, digital color multifunction peripherals (MFPs) equipped with various color image input / output devices have little image quality degradation even when only limited extension bits can be used in advance. An image processing apparatus that can convert an output image can be provided.

  Thirdly, in the second aspect, since the color space expansion uses the image area separation information as the upper bits of the color value, in a digital color multifunction peripheral (MFP) equipped with various color image input / output devices, Even when irreversible compression is performed on accumulated image data in order to suppress an increase in cost as much as possible, an image processing apparatus that can suppress false colors and convert an output image with little deterioration in image quality can be provided.

  Fourthly, in the second aspect, the incidental information of the input image data includes at least the definition of the color space, and relates to the expansion of the color space for each RGB plane using the image area separation information according to the properties of the input color space. Because the specifications have been changed, even in digital color multifunction peripherals (MFPs) equipped with various color image input / output devices, even if only limited extension bits can be used in advance, colors can be appropriately displayed in real time for input images. It is possible to provide an image processing apparatus that can perform an image quality improvement process using expansion or image area separation information and convert it to an output image with little image quality degradation.

  Fifth, in the second aspect, when the image data is input from an image reading apparatus, the incidental information of the input image data includes at least the type of the original to be read, and image area separation is performed according to the type of the original to be read. Since the specifications regarding the expansion of the color space for each RGB plane using information have been changed, in a digital color multi-function peripheral (MFP) equipped with various color image input / output devices, an input image from an image reading device is Therefore, it is possible to provide an image processing apparatus that can appropriately perform image quality improvement processing using color expansion or image area separation information using a limited number of expansion bits and convert the output image with less image quality degradation.

  Sixth, in the second aspect, when the image data is input from an external I / F device, the incidental information of the input image data includes at least a shooting condition added to the input image, and the shooting condition Therefore, the specifications regarding the expansion of the color space for each RGB plane using the image area separation information are changed accordingly, so that in a digital color multifunction peripheral (MFP) equipped with various color image input / output devices, a high dynamic range image Provides an image processing device that can appropriately color-extend an input image from an external I / F device including a large color gamut using limited extension bits and convert it to an output image with little image quality degradation can do.

  Seventhly, in the second aspect, since the operator has an I / F device for mode setting of color expansion specifications for each RGB plane using the image area separation information and the presence / absence of color expansion, In a digital color multifunction peripheral (MFP) equipped with a color image input / output device, the limited extension bits can be efficiently used to convert the input image into an output image that suppresses deterioration of the image quality that the user attaches importance to An image processing apparatus can be provided.

  As described above, the image processing apparatus according to the present invention is an image processing apparatus that performs image processing on digital image data in a digital multi-function peripheral that combines functions of a copying machine, a facsimile, a printer, a scanner, or the like, or a color facsimile, color Useful for image processing devices such as printers and color hard copies, and color / printing software that runs on a personal computer. In particular, unified colors (managed within the device) input from external I / F devices, etc. It is suitable for devices and systems that handle colors that cannot be expressed in space without deterioration and perform appropriate color conversion.

1 is a block diagram illustrating a system configuration of a digital color multifunction peripheral according to an embodiment of the present invention. It is a block diagram which shows the structure of the image data processing apparatus 2 in FIG. It is a block diagram which shows the structure of the image data processing apparatus 4 in FIG. It is explanatory drawing which shows the grid point output value in a color conversion process. It is explanatory drawing which shows the tetrahedron stretched by the lattice point used for interpolation by the tetrahedron for interpolation. It is explanatory drawing which shows the output normalization after 3D-LUT conversion. It is a block diagram which shows the hardware constitutions of this compound machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reading apparatus 2 Image data processing apparatus 3 Bus control apparatus 4 Image data processing apparatus 5 HDD
6 CPU
9 Plotter device 10 Operation display device 12 External I / F device

Claims (7)

An image reading device for obtaining image data obtained by reading a document and digitizing it;
An image forming apparatus for printing image data after image processing on recording paper;
A memory device for storing the image data and image area separation information of the image data;
An external I / F device that transmits and receives the image data and image area separation information of the image data, and an external device;
A first image data processing device for processing image data read by the image reading device;
A second image data processing device for processing image data received from the external device;
A third image data processing device for reading and processing the image data stored in the memory device;
A bus control device for connecting the devices;
With
The first image data processing device and the second image data processing device unify the properties of the image data input from the image reading device and the external device, and when unifying the properties, according to the image input conditions, wherein the predetermined bit of the image area separation information picture element units in the image data and co instead of extended color information used to extend the color information stored in said memory device, said third image data processing apparatus, wherein when converting the image data of the property of the input color space suitable for output to the image forming apparatus and the external I / F unit, and performs image processing based on the extended color information accumulated before Symbol memory device Image processing device. The unification of the nature of the image data is to be converted to a defined RGB color space, in accordance with the image area separation information of said image data without changing the nature of the defined RGB color space, the image The image processing apparatus according to claim 1, wherein specifications relating to expansion of a color space for each of RGB planes using area separation information are changed.   The image processing apparatus according to claim 2, wherein the expansion of the color space uses image area separation information as upper bits of a color value.   The image processing apparatus according to claim 2, wherein at least a color space definition is included, and specifications relating to color space expansion for each RGB plane using image area separation information are changed in accordance with the properties of the input color space. . If the image data is input from the image reading apparatus, comprising at least the type of the read document to the image area separation information of said image data, RGB each plane with the image area separation information in accordance with the type of read original The image processing apparatus according to claim 2, wherein a specification relating to expansion of a color space with respect to is changed. If the image data is input from the external I / F device includes a photographing condition to the image area separation information of said image data is added to the least image data, the image area separation according to the imaging condition The image processing apparatus according to claim 2, wherein specifications relating to expansion of a color space for each RGB plane using information are changed.   The image processing apparatus according to claim 2, further comprising: an I / F device that allows an operator to set a mode of whether or not color expansion is performed for each RGB plane using the image area separation information and whether or not color expansion is performed. .

Images