JP2006270816A - Image processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus which can offer the high definition image quality when outputting (especially sending) the image to various types of the output devices. <P>SOLUTION: The image processing apparatus provides the means including image information input, storage, output, storing, transmission/reception, control, primary resolution conversion, secondary resolution conversion, and color density conversion. This image processing apparatus has the switching characteristics of determining that the image information converted by the primary resolution conversion means should be subject to secondary resolution conversion, color density conversion, or non-conversion depending on the destination output devices. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing apparatus for realizing a color image processing system connected to a network.

  2. Description of the Related Art Conventionally, a device equipped with an electrophotographic printer such as a printer, a copier, or an MFP (Multi Function Peripheral) aims to express an image quality higher than the resolution of the printer, with a resolution higher than the print resolution of the printer. Description Language (Page Description Language) A configuration has been proposed in which data is bitmap-expanded and output. For example, PDL data is expanded into 1200 dpi bitmap data, and each expanded pixel is output by a 600 dpi printer using a spot multiplexing technique. This spot multiplexing technique is described in Patent Document 1, for example.

  Of course, in the above configuration, when handling data after bitmap development at 1200 dpi in the device, processing performance, memory, etc. four times that required for handling 600 dpi data will be required. That increases the cost of the equipment.

In order to solve this, PDL data is first developed at a high resolution (for example, 1200 dpi) and then converted to a low resolution (for example, 600 dpi), and in accordance with the attribute of the peripheral region of the target pixel determined according to the resolution conversion ratio. Thus, by selecting an appropriate value from a plurality of pixel values obtained by calculating the peripheral area of the target image, resolution conversion is performed while minimizing image quality degradation, and a high resolution equivalent to 1200 dpi is achieved while being 600 dpi. A technique for creating high-definition and high-quality bitmap data has also been proposed.
Japanese Translation of National Publication No. 06-504004

  However, the resolution conversion method that minimizes image quality degradation described above is an algorithm that is premised on output to an electrophotographic printer, so when it is transmitted to other external devices via a network, for example, When the image is transmitted to the PC and displayed on the display, the intended image quality may not be obtained.

  The present invention has been made paying attention to the above-described problems, and provides an image processing apparatus capable of obtaining high-definition image quality even when an image is output to various output devices (especially a send). With the goal.

  The present invention solves the above problem by switching the image processing applied to the bitmap data according to the output destination.

  That is, when output to a 600 dpi printer while reducing the memory capacity and handling load using the resolution conversion method that minimizes image quality degradation, the bitmap data after the resolution conversion is stored in the PC. When the image is displayed on the display after the resolution conversion, the bitmap data subjected to the image processing by the primary interpolation and the table conversion is respectively transmitted to the output destination by appropriately switching the image processing. It is possible to select an optimum process according to the process.

That is, the present invention provides image information input means for inputting image information,
Image information storage means for temporarily storing the input image information;
Image information output means capable of printing a color image using a plurality of toners;
Image information storage means for storing at least one or more input image information for a certain period;
Image information transmitting means for transmitting the image information to an external device connected via a network;
Image information receiving means for receiving the image information from an external device connected via a network;
Control means for controlling the image information input means, the image information storage means, the image storage means, the image information output means, the image information transmission means, and the image information reception means;
In an image processing apparatus comprising:
First resolution conversion means for performing resolution conversion on the image information input by the image information input means;
Second resolution conversion means for performing resolution conversion on the image information input by the image information input means;
Density conversion means for performing density conversion on the image information input by the image information input means;
When transmitting the image information converted by the first resolution converting means by the image information transmitting means, the image information is subjected to resolution conversion by the second resolution converting means, or by the density converting means. Switching means for switching between density conversion,
A switching control means for automatically switching the switching means according to a transmission destination transmitted by the image information transmission means;
An image processing apparatus comprising:

  In the present invention, an image with an optimum image quality is output by automatically switching image processing methods such as density conversion processing according to the output destination of bitmap data.

  Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings.

  FIG. 16 is a block diagram illustrating the overall configuration of the image forming apparatus system according to the embodiment of the present invention. The image forming apparatus 200 includes a scanner unit 2070 that is an image input device, a printer unit 2095 that is an image output device, a controller unit 2000, and an operation unit 2012 that is a user interface. The scanner unit 2070, the printer unit 2095, and the operation unit 2012 are respectively connected to the Controller Unit 2000, and the Controller Unit 2000 is connected to a network transmission unit such as a LAN 2011 and a public line. Transmission by G3 and G4 fax including color image transmission is possible from the public line. In addition, other image forming apparatuses 220 and 230 having the same device configuration as that of the image forming apparatus 200 can be connected to the LAN 2011. Further, a personal computer (hereinafter referred to as PC) 240 is connected, and can send and receive files and e-mails using FTP and SMB protocols. The image forming apparatuses 220 and 230 have scanner units 2270 and 2370, printer units 2295 and 2395, and operation units 2212 and 2312, which are connected to the controller unit 2200 and 2300, respectively.

  FIG. 17 is a block diagram illustrating the configuration of the image forming apparatus. The Controller Unit 2000 is connected to a color scanner 2015 as an image input device and a color printer 2017 as an image output device, and on the other hand, is connected to a LAN 2008 or a public line (WAN) 2051 to input / output image information and device information. Controller. A CPU 2001 is a controller that controls the entire system. A RAM 2002 is a system work memory for the operation of the CPU 2001, and is also an image memory for temporarily storing image data. A ROM 2003 is a boot ROM, and stores a system boot program. An HDD 2004 is a hard disk drive that stores system software and image data. An operation unit I / F 2005 is an operation unit (UI) 2006 and an interface unit, and outputs image data to be displayed on the operation unit 2006 to the operation unit 2006. Also, it plays a role of transmitting information input by the system user from the operation unit 2006 to the CPU 2001. A network 2007 is connected to the LAN 2008 and inputs / outputs information. A Modem 2050 is connected to the public line 2051 and inputs / outputs image information. Binary image rotation 2052 and binary image compression / decompression 2053 are for converting the direction of an image before transmitting a binary image by Modem 2050, or converting it to a predetermined resolution or a resolution adapted to the partner's ability. It is. Compression and decompression support JBIG, MMR, MR, and MH. A DMAC 2009 is a DMA controller that reads an image stored in the RAM 2002 without using the CPU 2001 and transfers the image to the ImageBus I / F 2011 or writes an image from the image bus into the RAM 2002 without using the CPU 2001. The above devices are connected to the system bus 2008. An ImageBus 2011 is an interface for controlling high-speed image input / output via the image bus 2010. A compressor 2012 is a compressor for JPEG compression in units of 32 pixels × 32 pixels before sending an image to the image bus 2010. A decompressor 2013 is a decompressor for decompressing an image sent via the image bus 2010.

  The raster image processor (RIP) 2018 receives the PDL code from the host computer via the network 2007, and the CPU 2001 stores it in the RAM 2002 through the system bus 2008. The CPU 2001 converts the PDL into an intermediate code, inputs it again to the RIP 2018 via the system bus 2008, and develops it into a bitmap image (multi-value). In the present embodiment, the RIP 2018 expands the intermediate code into a 1200 dpi bitmap image. Thereafter, the resolution of the image data is lowered by high-definition resolution conversion 2054. In this embodiment, 1200 dpi data is converted into a 600 dpi signal. This is a technique that enables conversion to 600 dpi data while maintaining phase information of a 1200 dpi image (details will be described later). In other words, even if the output is 600 dpi, the character (font) or line ratio (proportional) is processed so as to have a resolution level of 1200 dpi.

  The scanner image processing 2014 performs various appropriate image processing (for example, correction, processing, editing) on the color image and the black and white image from the scanner 2015 and outputs (multi-value).

  Similarly, the printer image processing 2016 performs various appropriate image processing (for example, correction, processing, editing) on the printer 2017. When printing, binary multi-value conversion is performed by decompression 2013, so binary and multi-value output is possible.

  The image conversion unit 2030 has various image conversion functions used when converting an image on the RAM and returning it to the RAM 2002 again. A rotator 2019 can rotate an image of 32 pixels × 32 pixels unit at a specified angle, and supports binary and multi-value input / output. The magnification changer 2020 has a function (for example, from 25% to 400%) for converting the image resolution (for example, from 600 dpi to 200 dpi) and for changing the magnification. Before scaling, the image of 32 × 32 pixels is rearranged into an image in units of 32 lines. The color space conversion 2021 converts, for example, a YUV image on the memory into a Lab image by matrix operation and LUT from the multi-valued input image, and stores it on the memory. Further, this color space conversion has a 3 × 8 matrix operation and a one-dimensional LUT, and can perform well-known background removal and show-through prevention. The converted image is output in multiple values. A binary multi-value conversion 2022 converts a 1-bit binary image into a multi-value 8-bit, 256 gradation. On the other hand, the multi-value / binary conversion 2025 converts, for example, an 8-bit, 256-gradation image on the memory into 1-bit, 2-gradation by a technique such as error diffusion processing and stores it on the memory. The composition has a function of composing two multi-valued image images on the memory into one multi-valued image. For example, a company logo can be easily attached to a document image by combining the image of the company logo in the memory with the document image. The thinning 2024 is a unit that performs resolution conversion by thinning out pixels of a multivalued image, and can output 1/2, 1/4, and 1/8 multivalued images. By using it together with the variable magnification 2020, a wider range of enlargement / reduction can be performed. The movement 2025 can be output by adding a margin portion to the input binary image or multi-valued image or deleting the margin portion. The rotation 2019, scaling 2020, color space conversion 2021, binary multi-value 2022, composition 2023, thinning 2024, movement 2025, and multi-value binary 2026 can be connected and operated. When the image is rotated and the resolution is converted, both processes can be performed without using a memory.

  FIG. 18 shows an image format. The image format used in the present invention uses the image packet structure disclosed in Japanese Patent Laid-Open No. 2001-103473. In compression 2012, raster format images are rearranged as packets of 32 × 32 pixel units as shown in FIG. 18, and JPEG compression is performed in packet units. At the same time, information such as an ID indicating the position of the packet, a color space, a Q table ID, and a data length is added to the packet to form a header. Further, binary data (image area flag) indicating characters and photographs is similarly compressed and attached after JPEG. FIG. 19 shows packet data. In decompression 2013, JPEG is developed based on this header information and rearranged into a raster image. By making such a packet image, only the image inside the packet is rotated at the time of image rotation, and by changing the position of the packet ID, it can be partially rotated by decompression and compression, so it is very efficient. . All images flowing through ImageBus 2010 are packet images.

  When a raster image is necessary for FAX transmission, binary image rotation 2052, binary image compression, expansion 2053, or the like, conversion from a packet image to a raster image is performed by software.

  FIG. 20 shows a detailed description of the scanner image processing 2014. The RGB 8-bit luminance signals input from the scanner are converted into standard RGB color signals independent of the filter color of the image sensor by masking 2501. In the filter 2502, for example, a 9 × 9 matrix is used, and an image is blurred or sharpened. A histogram 2503 is a processing unit that samples image signal data in an input image, and is used to determine the background level of the input image. In this module, RGB data in a rectangular area surrounded by the specified start and end points in the main and sub-scan directions is sampled at a constant pitch in the main and sub-scan directions, and a histogram is created. . This histogram is read when background skipping or prevention of show-through is specified, and the background of the original is estimated from the histogram, and is stored and managed in the memory or HDD along with the image as the background skipping level. Used for image processing. In gamma 2504, processing is performed so that the density of the entire image is increased or decreased. For example, it is a part that converts the color space of the input image into an arbitrary color space or performs correction processing relating to the color of the input system. In order to determine whether the document is color or black and white, the image signal before scaling is converted into a known Lab by color space conversion 2505. Of these, a and b represent color signal components, and a 1-bit determination signal is output from the comparator 2505 as a chromatic color if it is equal to or higher than a predetermined level in the comparator 2505 and otherwise as an achromatic color. A counter 2507 measures the output from the comparator. Character / photo determination is a function that extracts a character edge from an image and separates the image into characters and a photo. As an output, a character photograph determination signal is obtained. This signal is also stored in the memory or HD together with the image and used during printing. Reference numeral 2509 denotes a specific document determination device. The specific document determination unit can compare the input image signal and the degree to which the pattern held in the determination unit matches, and can read the determination result of matching or mismatching as illustrated. The image is processed according to the determination result to prevent counterfeiting of banknotes and securities.

  FIG. 21 shows a detailed description of the printer image processing 2016.

  In 2601, the background color of the image data is skipped, and unnecessary background fogging is removed. For example, background removal is performed by a 3 × 8 matrix operation or a one-dimensional LUT. This is a function included in 2032 as described above, and is a completely equivalent circuit. Reference numeral 2602 denotes a monochrome generation unit that converts color image data, for example, RGB data into Gray single color when converting color image data into monochrome data and printing it as a single color. For example, it is composed of a 1 × 3 matrix operation that multiplies RGB by an arbitrary constant to obtain a Gray signal. An output color correction unit 2603 performs color correction in accordance with the characteristics of the printer unit that outputs image data. For example, the image processing is configured by processing by 4 × 8 matrix calculation, direct mapping, or the like, and image signals of 6 colors of CMYKLcLm or 4 colors of CMYK are generated from input RGB image signals. In this embodiment, the six toner colors of the printer unit 2017 are cyan (C), magenta (M), yellow (Y), black (K), light cyan (Lc), and light magenta (Lm). A corresponding image signal or an image signal corresponding to four colors of cyan (C), magenta (M), yellow (Y), and black (K) is output at 600 dpi (dots per inch) and 8 bits each. . The output of the 6-color and 4-color image signals is switched by a process described in detail later. A filter processing unit 2604 arbitrarily corrects the spatial frequency of the image data, and includes, for example, processing for performing a 9 × 9 matrix operation. Reference numeral 2605 denotes a process for performing gamma correction in accordance with the characteristics of the printer unit to be output, and is usually composed of a one-dimensional LUT. A processing unit 2606 performs arbitrary halftone processing in accordance with the number of gradations of the output printer unit, and is a halftone processing unit that performs arbitrary screen processing such as binarization and binarization and error diffusion processing. is there. Each process can be switched by a character / photo determination signal (not shown). The inter-drum delay memory 2607 is a memory for superimposing CMYKLcLm images by shifting the print timing of CMYKLcLm by the distance between the drums in a color printer having CMYKLcLm color drums. In a color printer having 6 drums for each color of CMYKLcLm, it is possible to delay in order to align the positions of images for 6 colors for each color. Of course, even when the output of the output color correction unit 2603 has four colors of CMYK, the inter-drum delay unit 2607 can adjust the delay.

  An overview of the image input / output device is shown in FIG.

  The scanner unit 2015 illuminates an image on paper serving as a document and scans an image sensor (not shown), thereby converting it into an electrical signal as raster image data. The manuscript paper is set on the tray 2702 of the manuscript feeder 2701, and when the user gives an instruction to start reading from the operation unit 2006, the controller CPU 2001 gives an instruction to the scanner 2015 and feeds manuscript paper one by one from the tray 2702 of the feeder 2071. Read the original image.

  The printer unit 2017, which is an image output device, is a part that converts raster image data into an image on paper. In this embodiment, a color LBP that employs an electrophotographic system using a photosensitive drum, toner, and the like is used. In this embodiment, the printing method is an electrophotographic method. The print resolution is 600 dpi (dots per inch). The printer unit 2017 employs a six-tandem tandem system in which a photosensitive drum is prepared for each color. As described above, the basic colors C, M, Y, K, Lc, and Lm are combined with them. It is configured to enable various color printing. Here, the dark and light color developers are prepared by changing the amount of the pigment having the same spectral characteristics. Accordingly, the light magenta toner has the same spectral characteristics as the magenta pigment but has a small content, and the light cyan toner has the same spectral characteristics as the cyan but has a small content. By using dark and light colors for magenta and cyan, it is possible to reduce graininess in a light image such as human skin and improve reproducibility. Activation of the printing operation is started by an instruction from the controller CPU 2001. The printer unit 2095 has a plurality of paper feed stages so that different paper sizes or different paper orientations can be selected, and there are paper cassettes 2703, 2704, and 2705 corresponding thereto. A paper discharge tray 2706 is a paper discharge tray for receiving the printed paper.

  The configuration of the operation unit 2006 is shown in FIG. The LCD display unit 2801 has a touch panel sheet 2802 pasted on the LCD, displays a system operation screen and soft keys, and transmits the position information to the controller CPU 2001 when the displayed keys are pressed. A start key 2804 is used when starting a document image reading operation. There is a green and red two-color LED 2804 in the center of the start key 2803, and indicates whether or not the start key 2803 can be used depending on the color. A stop key 2805 functions to stop an operation in operation. An ID key 2806 is used when inputting the user ID of the user. A reset key 2807 is used when initializing settings from the operation unit.

  FIG. 24 shows an initial screen in the image forming apparatus of the present embodiment, and is also a standard screen that is returned after setting each image forming function. 3101 performs screen switching for performing copy settings. 3102 performs screen switching for setting to send the scanned image by fax or electronic mail. A screen 3103 stores a scan image and a PDL image in the built-in HDD, or performs screen switching for setting the print, transmission, or editing of the stored scan image and PDL image. Reference numeral 3104 denotes a window for displaying the image reading settings set in 3105. In 3105, resolution, density, and the like at the time of image reading are set. Reference numeral 3106 denotes a timer setting at the time of timer transmission and a setting for printing on the HDD or printer. 3107 displays the transmission destination designated by 3108. 3109 displays detailed information of one destination displayed in 3107. 3110 deletes one destination displayed in 3107.

  FIG. 25 is a pop-up window displayed when 3105 is pressed. In 3201, the read original size is selected and input from the pop-up, and the set read size is displayed in 3202. Reference numeral 3203 denotes a selection of a document reading mode. When pressed, three types of color / black / automatic (ACS) can be selected. The color mode can be selected in the same way for copy and box. If the measurement result of the counter 2507 is smaller than a predetermined value, it is determined as a black and white document, and if it is larger, it is determined as a color document. If it is color, a color image is displayed, if it is black, a monochrome image is displayed. Accumulate the result of determining whether it is color or black and white. 3204 is a selection input from a pop-up for designating the resolution of reading. Reference numeral 3205 denotes a slider for adjusting the reading density of the original, and can be adjusted in nine steps. 3206 is for automatically determining the density when reading an image with a background such as a newspaper. For 3206, the same setting can be made by copying.

  FIG. 26 shows a screen when the copy tab 3101 is pressed. 3301 indicates whether or not copying is possible, and the number of copies set at the same time is also displayed. A function 3302 is equivalent to the function 3206, and is a button for selecting whether to automatically remove the background. Reference numeral 3303 denotes a slider having a function equivalent to that of 3205 and capable of nine levels of density adjustment. In 3304, the type of the original is selected, and a character / photo / map, text, a photographic paper photo, and a printed photo can be selected. Reference numeral 3305 denotes an application mode button which can set a reduced layout (a function for reducing and printing a plurality of originals on one sheet), a color balance (CMYK color fine adjustment), and the like. Reference numeral 3306 denotes a button for performing settings relating to various finishings, and shift sort, staple sort, and group sort can be set. Reference numeral 3307 denotes a button for performing settings relating to duplex reading and duplex printing.

  FIG. 27 shows a screen when the box tab 3103 is pressed. Reference numeral 3401 denotes each folder logically divided into HDDs. Folder numbers are assigned in advance to the folders, and 3401 becomes the 0th folder. Next to the folder number, the percentage of disk space used by the folder is displayed. Folders can be given any name, and the name is displayed here. 3402 displays the usage amount of the entire HDD.

  FIG. 28 shows a screen when 3401 is pressed. Reference numerals 3501 and 3502 denote documents stored in folders. A document is composed of a plurality of pages. Reference numeral 3501 denotes a scanned document, which displays an icon display indicating a scanned document, an HDD usage amount, and a document name display that can be arbitrarily set by the user. An icon 3502 is a PDL document stored from the PDL. By depressing the icon, it is shown in reverse video that the document has been selected. Reference numeral 3503 denotes a button for transmitting the selected document. Reference numeral 3504 denotes a button for reading a document from the scanner and generating a document. Reference numeral 3505 denotes a button for selecting all the documents in the folder. Reference numeral 3506 denotes a button for deleting the selected document. Reference numeral 3507 denotes a button for printing the selected document. Reference numeral 3508 denotes a button for editing the selected document. For example, it has a function of selecting and combining two documents, saving them as one document, and deleting a specific page. Reference numeral 3509 denotes a button for displaying detailed information of the last selected document. In addition to the document name, information such as resolution, document size, and color can be viewed.

  FIG. 1 is a diagram for explaining the high-definition resolution conversion unit 2054. The 1200 dpi image area signal (Z sig.) 112 and the 1200 dpi data 113 shown in FIG. 1 are input signals and represent an image signal PDL-developed to 1200 dpi. More specifically, 113 is an image signal, and 112 is an image area signal corresponding to the pixel. The image area signal is given to each pixel, and is an identification signal representing attribute information indicating whether the pixel belongs to a character (font), a photograph (graphic), an image (image), or the like.

  Although details will be described later, reference numeral 101 in FIG. 1 denotes the image area signal conversion unit described above. Here, the 1200 dpi image area signal is converted into a 600 dpi image area signal.

  Reference numerals 102 and 111 denote selectors that can select whether a 1200 dpi image area signal is output as it is or a 600 dpi image area signal converted in 101 is output by a reg_through signal from the register. Reference numeral 103 denotes an image signal converter. The image signal converter 103 converts a 1200 dpi image signal to 600 dpi. Details of the image signal conversion unit 103 will be described below.

  Reference numerals 104 and 110 denote luminance density conversion units. When the signal developed at 1200 dpi is a luminance signal, the luminance density conversion units 104 and 110 invert the luminance signal. FIG. 3 is a block diagram showing input / output signal names for explaining the luminance density converter. Here, the input signal is buffIN, and the output signal is InData. When the input signal buffIN is a luminance signal, the luminance density conversion units 104 and 110 invert when the switching signal input based on the register setting is 1, and output the input signal as it is when the switching signal is 0. Here, inversion means that 255 in the 8-bit signal becomes 0 and 255 becomes 0.

  Reference numeral 105 denotes an 8-bit FiFo memory. Two lines are delayed for a product-sum operation processing unit 106 to be described later. As a result, calculation with a maximum mask size of 3 × 3 is possible. Further, the signal (B) of the target pixel line is input to the L conversion unit 107. Then, it is converted into a 3-bit signal by a process described later.

  Reference numeral 106 denotes the product-sum operation processing unit described above. The product-sum operation processing unit performs eight types of processing. Specifically, the eight types of processing include processing for detecting the maximum value in the 3 × 3 area (No. 0), processing for detecting the maximum value in the 2 × 2 area (No. 1), A process of outputting the value of the target pixel as it is (No. 2) and a process of performing a product-sum operation in five types of 3 × 3 areas each having a different coefficient (No. 3 to No. 7). Details of the processing will be described with reference to FIG.

  First, FIG. 4A shows the entire block of the product-sum operation processing unit 106. The input signal InData (x) 601 is 8 bits of 3 lines of Line (A) 602, Line (B) 603, and Line (C) 604, and the output signal is 8 bits of OUT 605. FIG. 4B is a diagram illustrating the range of each area with respect to the target pixel 609. This figure shows a state in which the positional relationship between the 3 × 3 area 608 and the 2 × 2 area 607 is shifted with respect to the target pixel 609.

  In FIG. 4B, the target pixel 609 is a pixel specified by diagonal lines. Block movement of the product-sum operation processing unit 106 (actually, a physical block does not move on the memory (register), but a process in which 9 pixels are input to the 3 × 3 memory (register)) is performed. In this case, the ease of image is obtained and expressed in this manner) is controlled so that the target pixel 609 is selected every other pixel in the main scanning direction or the sub-scanning direction. That is, in FIG. 4B, when the pixel at the start point (0, 0) is the target pixel in the 3 × 3 area, the center of the 3 × 3 area is positioned so as to match the target pixel. After the product-sum operation process using 9 pixels in the 3 × 3 area is performed, the center of the 3 × 3 area is adjacent to, for example, 2 pixels in the right direction (main scanning direction) from the start point (0, 0). The position pixel is moved so as to be the target pixel, and product-sum operation processing is performed using the eight pixels around the target pixel. The direction of movement is not limited to the right direction.

  For example, if processing is performed every other pixel (in the main scanning direction) or every other line (in the sub scanning direction) as indicated by hatching with respect to a 1200 dpi pixel, the pixels are substantially thinned out by one pixel for every two pixels ( Therefore, the number of pixels in the main scanning direction is halved and the number of pixels in the sub scanning direction is halved. As a result, it can be converted into 600 dpi data. However, in the present invention, it is clear that not only one of the two pixels is thinned out. Further, what kind of processing is performed will be described later.

  Each process will be described below in order. No. 106 in FIG. In the detection process of the maximum value in the 3 × 3 area output to 0, the pixel value is compared in the 3 × 3 area centered on the target pixel in FIG. The value is detected. Similarly, no. In the process of detecting the maximum pixel value in the 2 × 2 area output to 1, the maximum pixel value in the 2 × 2 area of FIG. 4B is detected.

  No. In 2, the pixel value of interest is output through. That is, the signal of the pixel of interest in Line (B) is output through. No. The output value of 3 is the result of product-sum operation performed in the range of 3 × 3. Details of this calculation will be described with reference to FIG. In FIG. 4C, a to i in the mask register 611 are register setting values (weighting factors to be applied to each pixel), and 6-bit values are arbitrarily set. Each register value and the input signal x for each pixel of the image data 612 corresponding to each register value are summed up based on the following equation shown in FIG.

OUT = (a * x (i−1, j−1) + (b * x (i, j−1) + (c * x (i + 1, j−1))
+ (D * x (i-1, j) + (e * x (i, j) + (f * x (i + 1, j))
+ (G * x (i-1, j + 1) + (h * x (i, j + 1) + (i * x (i + 1, j + 1))) >> 6 (Formula 1)
In this calculation, the total value of 9 pixels of the product of the input signal x of each pixel and the register set value at the corresponding position is shifted to the right by 6 bits. This bit shift is a process equivalent to dividing the total value by 64. The final result obtained by clipping the result obtained by this calculation at 255 is No. 3 is output.

  In the equation shown in FIG. 4C, each underlined portion is 14 bits. Since the output is finally clipped at 255, the output OUT is 8-bit data. In the above, the product-sum operation in the 3 × 3 area has been described. If a, b, c, d, and g are set to 0 among the register setting values a to i, the product in the 2 × 2 area is set. It is clear that sum operation is possible.

  No. 4, no. 5, no. 6, no. 7, each using an arbitrary mask register 611, No. 7. The same calculation as that for outputting 3 is performed. The set value of the mask register 611 used here may be different for each output, or the same value may be set.

  These coefficients are set in advance in a register using a CPU. The set values used in this embodiment are different coefficients as shown in FIG. Each of these coefficients and an input image signal corresponding to the coefficient position are subjected to a product-sum operation.

  These coefficients are for controlling the generated half dots according to the input signal level.

  For example, when the input signal value is low, a coefficient such as no3 is prepared so that the half dot adjacent to the dark dot does not become too small by the product-sum operation. Conversely, when the input signal value is high, a coefficient such as no7 is prepared so that the half dot adjacent to the dark dot does not become too dark. The input signal here is a signal 107 obtained by converting the value of the target pixel into 3 bits.

  The processing result No. described above. 0-No. 7 is selected by a selector 109 that is output from the product-sum operation processing unit 106 of FIG. In other words, the image processing unit 304 according to the present embodiment is characterized by having a configuration capable of switching the optimum process for each pixel in accordance with the feature and pixel value (pixel density level) of each pixel. In addition, by performing the above processing in the image processing unit 304, adaptive image conversion in consideration of the non-linear characteristics of electrophotography can be performed.

  Returning to the description of FIG. As shown in FIG. 6, the L conversion unit 107 includes a memory having an address space of 8 bits and data of 3 bits, and receives a target pixel value of 8 bits on the line (B). Then, the L converter outputs a 3-bit signal. As an example, a value of “X / 52 + 3” is set in the L conversion unit. This X is assigned with the pixel value of interest, and takes any value from 0 to 255. That is, in the L conversion unit 107, any pixel value of 0 to 255 is input to X in the above formula, and any value of 3 to 7 is obtained by calculation. This value reflects the density of the target pixel. The remainder generated in the above calculation is discarded.

  The mask selection signal generation unit 108 includes the above-mentioned No. 108. 0-No. A signal for selecting the product-sum operation result of 7 is generated. Details of the processing will be described with reference to FIG. The mask selection unit 108 receives an output signal L702 from the L conversion unit 107 and an output sd701 from an image area signal conversion unit 101 described later, and a 3-bit selection signal 703 is generated and output to the selector 109.

  More specifically, the selection signal 703 is generated according to the value of the 2-bit sd signal 701. The output 703 from the mask selection signal generation unit 108 is obtained from the selector 109 as No. 0-No. 7 is used as a signal for selecting 7 outputs. Therefore, the mask selection signal is 3 bits (0 to 7), and when the sd signal 701 is 0 to 2, No. 0-No. A signal 703 for selecting 2 is output. When sd = 3, the selection signal 703 is output based on the value of the L signal (that is, the density value of the target pixel). Although the L signal is a 3-bit signal, the output from the L conversion unit 107 is any one of 3 to 7 as described above. 3-No. A selection signal 703 (any one of 3 to 7) for selecting any one of 7 is output.

  Since 3 to 7 of the output signal 703 from the mask selection signal generation unit 108 described above are created with reference to the density value of the input image signal 113 of 1200 dpi, the optimum value according to the density of the input signal value 113 is obtained. It is characterized in that the product-sum operation result can be selected. That is, it is possible to select a product-sum operation result in consideration of the non-linear characteristics peculiar to electrophotography for each pixel. Of course, it is possible to cope with selection in consideration of ink bleeding in a printer that forms an image by ejecting ink, such as an ink jet printer.

  Further, since the image processing unit 304 can be controlled using the value of the sd signal 701 generated by the image area signal conversion unit 101 described later, a character part, a small-diameter character (for example, less than 4 points), a line part, an image part Thus, the result of the product-sum operation processing unit 106 can be arbitrarily selected. That is, there is an effect that the resolution conversion process can be switched between a small-diameter character that emphasizes legibility and a character that emphasizes proportion. For example, small diameter characters such as less than 4 points are No. No. 2 pixel value is selected. This is a process such as selecting a product-sum operation result of 3-7. Further, it is possible to obtain an excellent effect that only an arbitrary image area can be set to 1200 dpi image quality, or only an arbitrary density can be set to 1200 dpi image quality.

  Using the selection signal output from the mask selection signal generation unit 108 described above, the selector 109 selects eight types of outputs from the product-sum operation processing unit 106, thereby maintaining 600 dpi data while maintaining the 1200 dpi image quality. Can be converted to This is because a resolution conversion process according to the characteristics of each input 1200 dpi pixel is performed using a pixel value (density value) of each pixel and an image area signal for each pixel described later.

  The above-mentioned 600 dpi data maintaining an image quality equivalent to 1200 dpi is sent to the printer via the luminance density converter 110 and the selector 111 and is output. Therefore, even when the printer has only an output resolution of 600 dpi, a quality substantially equivalent to 1200 dpi can be ensured as long as the data subjected to the processing in this embodiment is output.

[Image area signal converter]
Hereinafter, the image area signal conversion unit 101 will be described. FIG. 2 is an overall block diagram of the image area signal conversion unit. Reference numeral 400 denotes an 8-bit FiFo memory, which is delayed by two lines in the same manner as the FiFo memory 105 described above. As a result, processing in a 3 × 3 range described later becomes possible.

  401, 402, and 403 8/4 conversion units are processing units for converting an input signal 8 bits into a 4-bit signal. Details of processing in the 8/4 conversion units 401 to 403 will be described with reference to FIG. (B) in FIG. 7 is a block diagram showing the whole of the 8/4 conversion unit. The input is represented by 8-bit data 901 and the output is represented by 4-bit FTData 907.

  FIG. 7A shows an example of the internal configuration of the 8/4 conversion unit. A0, A1, A2, and A3 are 3-bit bit selection registers 906, which are configured to select the designated bit. More specifically, for the 8-bit data 901 of the input signal, one bit is selected in each of the four registers 902 to 905 based on an arbitrary bit specified by the bit selection register 906, so that a 4-bit output is output as the FTData 907. Will be obtained.

  For example, when 8-bit data of “00101000” is input as data 901 and the output from A3 of the bit selection register 906 is “010”, the 8/1 selection unit 902 selects the third bit, and the output out3 is 0. It becomes. In the other 8/1 selection units 903 to 905, a 1-bit output can be obtained in the same manner as described above.

  Returning to the description of FIG. Reference numerals 404, 405, and 406 denote inversion processing units that invert the signal. Here, the inversion process is a bit inversion process in which the input signal “1111” is output as “0000” and the input signal “1010” is output as “0101”.

  Details of the inversion processing units 404 to 406 will be described with reference to FIG. FIG. 8B is a block diagram illustrating the entire inversion processing unit, and FIG. 8A is a block diagram illustrating an example of an internal configuration of the inversion processing unit. The register A7 (1006) is a 4-bit selection signal and can invert a designated arbitrary bit.

  Specifically, the inversion processing unit includes exclusive OR operation units 1002 to 1005, and each exclusive OR operation unit performs exclusive OR operation between the register A7 (1006) and the input signal 1001, An operation result is output for bit 3, 1003 for bit 2, 1004 for bit 1, and 1005 for bit 0. Therefore, if the register A7 is “1111”, the input signal 1001 is output with all bits 3 to 0 inverted, and if it is “1000”, only the bit 3 is inverted.

  In FIG. 2, the 4/3 conversion units 407, 408, and 409 newly generate a 3-bit image area signal based on the 4-bit signal obtained by converting the 8-bit image area signal by the 8/4 conversion unit. Processing to do. This is because the input image area signal is 8 bits in the present embodiment, and thus includes various information. Therefore, selecting the 4 bits, which is necessary information in the 8/4 conversion unit, and finally converting the selected 4 bits into 3 bits, rather than converting directly from 8 bits to 3 bits, the amount of delay memory, etc. This is because the cost can be reduced and the cost is reduced.

  Now, details of the processing in the 4/3 conversion unit will be described with reference to FIG. FIG. 9B is a block diagram illustrating the entire 4/3 conversion unit, and FIG. 9A is a diagram illustrating an example of an internal configuration of the 4/3 conversion unit. First, FIG. 9B shows a configuration in which 4-bit inout data 1101 is input and 3-bit inout data ′ 1102 is output.

  FIG. 9A shows the processing in logic, and bits 0 to 3 correspond to the inoutdata 1101 shown in FIG. 9B. This inoutdata 1101 is the image area signal after the arbitrary bit selection described above. Further, bit0 to bit2 correspond to indata '1102 shown in FIG. 9B, and represent a newly generated image area signal.

The meaning of each of the four bits 1101 used in the present embodiment is as follows. Of course, this is only an example, and the present invention does not limit the number of bits and the meaning set for each bit to the following.
bit0: Vector (1), non-vector (0)
bit1: chromatic color (1), achromatic color (0)
bit2: Character (1), Non-character (0)
bit3: Object present (1), object absent (0)
The 4/3 conversion unit generates a new image area signal for the 1101 signal by setting from the register A to the register E shown in FIG.

  Each register will be described. The register A is a setting signal for determining whether or not the chromatic / achromatic signal of bit 1 is forcibly made a chromatic color determination, and whether the register B uses the character / non-character signal of bit 2 as it is. This is a setting signal for determining whether to use the image reversed or forcibly fixing to character determination, and for setting the register C to use image area determination related to the character or forcibly setting it to 1 or 0. , Register D is a setting signal for determining whether or not to use image area determination related to graphics, and register E is a setting signal for determining whether or not register E uses image area determination for an image.

  That is, in the new image area signal created in this way, bit2 is a bit representing determination regarding an image, bit1 is a bit representing determination regarding a graphic, and bit0 is a bit representing determination regarding a font.

  In the present embodiment, the above-described bit2, bit1, and bit0 are assigned in the order of image, graphic, and font. However, the present invention is not limited to this, and it is needless to say that another order of font, image, and graphic may be used.

  The area determination unit 410 shown in FIG. 2 performs the processing described below in a 2 × 2 or 3 × 3 region. Details of the processing will be described with reference to FIG.

  First, the block diagram of FIG. 10B is a block diagram showing the entire area determination unit 410. Signals input to the area determination unit 410 are three lines (Line (a) 1207, Line (b) 1208, and Line (c) 1209) of each 3-bit FTData signal output from the 4/3 conversion units 407 to 409. Yes, it indicates that the output signal is 4-bit area1 (1211) and 2-bit area2 (1212).

  FIG. 10A shows 2 × 2 (1201) and 3 × 3 (1203) areas. A portion surrounded by a thick frame in each area is a target pixel. Which area is used is determined based on the setting of a register TT (not shown). Further, the numerical values from 0 to 8 described in FIG. 2 and FIG. 4 in FIG. 10A indicate the priority order of pixels to be described later, and numerical values of 0 and 1 described in FIG. 1 and FIG. Represents the value of the input signal FTData. Here, only 0 and 1 are shown, but since FTData is a 3-bit signal, it is clear that there can be signals from 0 to 7. The priorities shown in FIG. 2 and FIG. 4 in FIG. 10A are determined by the distance from the target pixel position. For example, in the case of the 3 × 3 region shown in FIG. 4, the priority order of the target pixel position is the highest, and the surrounding priority order is set to be lower in order. Of course, the present invention is not limited to this order, and there is no problem even if the order of priority is counterclockwise. What is important here is that the priority of the position of the target pixel is the highest, and the priority becomes lower as the surrounding pixels move away from the target pixel. In the case of 2 × 2 FIG. 2, since the area is small, the above description is difficult to understand, but priority is assigned for that reason.

  The reason why the above-described processing is performed in a 3 × 3 or 2 × 2 area is that, for example, when the resolution is converted from 1200 dpi to 600 dpi, it is necessary to detect whether an arbitrary image area signal exists in the area. It is. This makes it possible to perform processing such as applying this method only to characters (fonts) according to the detected signal.

  Details of the processing will be described below. First, when the register TT is set to 0, the 2 × 2 area 1201 is selected. Here, processing for detecting the maximum value of the input signal FTData is performed based on the order shown in the priority order 1204. Then, at which priority position the maximum value is detected is output as a signal of area1 (1211). That is, the pixel position having the maximum value in the area 1201 is determined. The area 2 signal 1210 is configured to output the sum (OR) of pixel values for four pixels.

  Next, when the register TT is set to 1, the 3 × 3 area 1202 is selected and processed. Since the processing performed here is the same as the processing performed for the 2 × 2 area 1201, detailed description thereof will be omitted. However, it is necessary to note that the area 1 signal is also 0 to 8 and the number of output bits is 4 bits because the pixel area to be referenced is expanded to 3 × 3. The rest is the same as described above.

  By the way, the register TT may be a fixed value, but can be switched via the CPU in accordance with attributes such as characters and graphics of the input data. For example, for dense data such as characters, a 2 × 2 area is selected so that the converted data is not crushed, and a 3 × 3 area is selected for graphic lines and figures. It is usage. The area determination unit 410 converts 1200 dpi data into 600 dpi data by processing every other pixel or every other line, like the product-sum operation processing unit 106 shown in FIG. However, since the thinning process is not performed, but the mask process as described above is performed, an image area signal equivalent to 1200 dpi can be expressed even with data after 600 dpi conversion.

  It will be apparent to those skilled in the art that even when 2400 dpi data is converted into 1200 dpi data, it can be processed every other pixel or every other line. Furthermore, for example, when a conversion process for converting the resolution to 1/4, such as converting 2400 dpi data to 600 dpi data, is desired, the mask size is set to 4 × 4 or 5 × 5, and every 3 pixels or every 3 lines. To process. As a matter of course, it can be understood that image data having as much image quality as possible and having a resolution of 1/4 can be obtained by processing similar to that described above.

  Now, the 8/1 conversion & ZSG selection processing unit 411 in FIG. 2 performs a process of detecting a small-diameter image in the area and a process of selecting an input DataZ at an arbitrary position in accordance with the area1 signal 1211 described above. . DataZ is an input image area signal of 1200 dpi. However, when any of the image area signals belonging to a predetermined area such as a 3 × 3 area indicates predetermined information such as a small-diameter character, the image area signal of the pixel of interest in this area is represented as that information. Convert.

  Details of the processing will be described below with reference to FIG. FIG. 11B is a block diagram illustrating the entire 8/1 conversion & ZSG selection processing unit 411. Here, the input signal is an 8-bit image area signal 1301 of 1200 dpi and a 4-bit area 1 signal 1211, and the output is a 1-bit point_fg 1308 signal and an 8-bit zs signal 1309. The point_fg signal 1308 is a signal indicating whether or not the small-diameter image is in the area, and the zs signal 1309 is an image area signal selected by the area1 signal 1211.

  The block diagram shown in FIG. 11A is the point_fg signal generator described with reference to FIG. Here, for one line of DataZ (1301) inputted in three lines, an arbitrary bit is selected by the register A4 (1304) and the register A5 (1305). In this embodiment, the bit 4 small-diameter flag is selected in the register A4 (1304), and the bit 2 character flag is selected in the register A5 (1305). Then, an integration process is performed in the AND gate 1306 to generate a small-diameter image signal.

  Similar processing is performed on other lines to generate a small-diameter image signal in a 2 × 2 or 3 × 3 area. These signals are summed via an OR gate 1308 to generate a point_fg signal 1308. The selection of this area is executed based on the register TT as described above. In this embodiment, as shown in FIG. 11A, the signal selected by the register A4 (1304) can be inverted by the register A8 (1310). However, the signal may be used without being inverted. .

  Next, ZSG signal generation processing in the ZSG selection processing unit will be described. Here, processing for selecting an input DataZ signal at an arbitrary position is executed in accordance with the area1 signal 1211 described above. The arbitrary position is a position from 0 to 8 in the priority order 1311 shown in FIG. 11C, the center (target pixel) corresponds to 4 bits 0 of the area 1 signal 1211, and other pixels are also The number assigned to each pixel corresponds to the bit value of the area1 signal 1211.

  In this way, by selecting the DataZ signal 1301 corresponding to the area1 signal 1211, simple decimation processing of one pixel and one line from 1200 dpi to 600 dpi is not performed, but the image area signal of each pixel and the density level of each pixel. It is possible to perform resolution conversion according to the characteristics.

  Reference numeral 412 in FIG. 2 denotes a bit conversion unit. The bit conversion unit 412 is configured by a memory having an address space of 4 bits and data of 2 bits. Although a detailed description of the processing is omitted, an outline of the memory data used in this embodiment will be described with reference to FIG. In FIG. 12, the horizontal axis, bit3 (1401) to bit0 (1404) represents the output area2 (1210) from the area determination unit 410 and the output point_fg (1308) from the 8/1 conversion unit / ZSG selection processing unit 411. Is the combined value of The combined value is a processing result of point_fg [3down3] + area2 [2down0]. A 4-bit signal can be generated by this calculation. Therefore, the horizontal axis of the table shown in FIG. 12 is represented by bit3 (1401) to bit0 (1404) as described above.

  Next, the number shown on the input axis 1405 on the vertical axis is the decimal representation of bit3 to bit0 described above. An output axis 1406 indicates a 2-bit output signal value, and in this embodiment, a meaning (1407 to 1422) described outside the column is given. For example, when input = 1, it is determined that the image is a character image (font: 1408) and 3 is output as an output 1406. When input = 2, it is determined that the image is graphic (graphic: 1409) and 1 is output. Is output.

  This output corresponds to the sd signal 701 input to the mask selection signal generation unit 108 described with reference to FIG. That is, when 3 is output, No. calculated by the product-sum operation processing unit 106 via the mask selection signal generation unit 108. 3-No. When “7” is selected and “1” is output, the No. 7 calculated by the product-sum operation unit 106 via the mask selection signal generation unit 108 is similarly obtained. 1 will be selected. When the sd signal is 3, in this case, based on the value of the L signal (that is, the density value of the target pixel), the No. 3-No. One of 7 is selected. Details of this processing are as described above.

  In this way, by switching the output of a plurality of values calculated in advance by the product-sum operation processing unit 106, it is possible to convert the optimum 1200 dpi to 600 dpi for each image type, that is, for each pixel.

  By the way, in the margin (1416-1422) of input = 9-15 in FIG. 12, “minor” is written, which means that a small diameter flag was present. In other words, this indicates that a small-diameter character, a small-diameter graphic such as an ultrathin line, or a small-diameter image such as a small-diameter image exists in an arbitrary area. In this case, 2 is output. As a result, since the sd signal 701 is 2, the product-sum operation processing unit 106 performs No. A value of 2 will be output. That is, the pixel-of-interest signal itself that is not subjected to the product-sum operation is output.

  The reason for this is that when the above product-sum operation is performed, 1200 dpi data can be expressed as 600 dpi data, but small diameter characters and thin lines are crushed due to the characteristics of electrophotography, and the line width changes greatly. There is a problem that legibility and image quality are degraded. Therefore, for small-diameter characters, the process of outputting the pixel value of interest as it is is performed, and “readability / prevention of image quality deterioration” and “1200 dpi data expression by 600 dpi data” are enabled.

  As described above, the result of the product-sum operation processing unit 106 described above is switched according to an image area signal such as a graphic / character / image of 600 dpi corresponding to 1200 dpi created by the above-described processing, so that it corresponds to each image area. Further, the optimum resolution conversion from 1200 dpi to 600 dpi is possible, and high-definition image processing is possible.

  In FIG. 2, reference numeral 413 denotes an ON / OFF switching signal generator, which will be described in detail with reference to FIG. FIG. 13 is a block diagram showing the entire ON / OFF switching signal generation unit 413. Here, an ON / OFF signal 1502 is generated according to the sd signal 1501 generated by the bit conversion unit 412. Specifically, 1 is output when the sd signal 1501 is 3, and 0 is output otherwise.

  The signal SWAP unit 414 performs a process of rewriting an arbitrary bit in accordance with the output on_off signal 413 described above. The details are as shown in FIG. FIG. 14B is a block diagram showing the entire SWAP unit, and FIG. 14A is a diagram showing an example of the internal configuration of the SWAP unit. As shown in FIG. 13B, the SWAP unit 414 has an 8-bit zs (1600) input signal and a 1-bit on_off signal (1601), and an output signal 8-bit out (1611).

  Specific processing in the SWAP unit 414 will be described below with reference to FIG. The 8-bit bit selection register A6 (1602) is a register for designating a bit for bit replacement. The register has a bit selector configuration in which an arbitrary bit of the input zs signal 1600 can be replaced with an on_off signal 1601 in selectors 1603 to 1610.

  In such a configuration, only when the sd signal 1600 is 3, 1 is set to an arbitrary bit set in the register A6 (1602), and 0 is set otherwise. That is, when the sd signal 1600 is 3, it means that the product-sum operation process has been performed, and therefore, it is added to the image area signal as a signal indicating whether or not this process has been performed. Become.

  With the above configuration, the image area signal converted by the image area signal conversion unit 101 and the sd signal indicating the presence or absence of the product-sum operation can be output.

  FIG. 29 shows a software configuration diagram. Reference numeral 4010 denotes a UI control unit that controls the display operation unit, a copy application unit 4020 that receives an instruction from the UI control unit, and executes a copy operation, a transmission operation, a scan from a box screen, and a print, a transmission application unit 4021, and a BOX application unit 4022. There is also a PDL application unit 4023 that receives PDL print data from the network application 4120 and inputs a PDL print job. Reference numeral 4030 denotes a common interface part for absorbing a device-dependent part of the device control part, and 4040 denotes a job manager that organizes job information received from the common interface and transmits it to a lower-level document processing unit. If the document processing unit is a local copy, the scan manager 4050 and the print manager 4090, a remote copy transmission job or a transmission job, the scan manager 4050 and the file store manager 4100, and a remote copy reception job, the file read manager 4060. And a print manager 4090, and PDL manager 4070 and print manager 4090 for PDL printing such as LIPS and PostScript. An image processing request to the image manager 4110 that performs synchronization between the document managers and performs various image processing is performed via the sync manager 4080. The image manager 4110 performs image processing and image file storage during scanning and printing.

  The following describes software control that changes image processing according to the output destination of image data, which is characteristic in the present invention.

  First, local copy software processing will be described. A copy setting is transmitted from the UI control unit 4010 together with a copy instruction to the copy application unit 4020 according to a user instruction. The copy application unit 4020 transmits information from the UI control unit 4010 to the job manager 4040 that performs device control via the common interface 4030. The job manager 4040 transmits job information to the scan manager 4050 and the print manager 4090. The scan manager 4050 issues a scan request to the scanner 2070 via a device I / F (not shown) (the device I / F is a serial I / F connecting the controller 2000 and the scanner 2015 and the controller 2000 and the printer 2017). At the same time, an image processing request for scanning is issued to the image manager 4110 via the sync manager 4080. The image manager 4110 sets the scanner image processing unit 2014 in accordance with an instruction from the scan manager 4050. When the setting is completed, a scan preparation completion is notified via the sync manager 4080. Thereafter, the scan manager 4050 instructs the scanner 2070 to scan. The completion of scan image transfer is transmitted to the image manager 4110 by an interrupt signal from hardware (not shown). Upon receiving the scan completion from the image manager 4110, the sync manager 4080 notifies the scan manager 4050 and the print manager 4090 of the scan completion. At the same time, the sync manager 4080 instructs the image manager 4110 to file the compressed image stored in the RAM 2002 into the HDD 2004. The image manager 4110 stores the image (including the character / photo determination signal) on the memory in the HDD 2004 according to the instruction. A color determination / monochrome determination result, a background skip level for performing background skip, a scanned image, and a color space RGB as an image input source are also stored in an SRAM (not shown) as accompanying information of the image. When the storage in the HDD 2004 is completed and the scan completion from the scanner 2070 is received, the scan manager 4050 is notified of the completion of file formation via the sync manager 4080.

  The scan manager 4050 returns an end notification to the job manager 4040, and the job manager 4040 returns it to the copy application unit 4020 via the common interface 4030. The print manager 4090 issues a print request to the printer 2095 via the device I / F when an image is stored in the memory. At the same time, a print image processing request is sent to the sync manager 4080. Upon receiving a request from the print manager 4090, the sync manager 4080 requests the image manager 4110 for image processing settings. The image manager 4110 sets the printer image processing unit 2016 according to the accompanying information of the image, and notifies the print manager 4090 of completion of print preparation via the sync manager 4080. The print manager 4090 issues a print instruction to the printer. The completion of print image transfer is transmitted to the image manager 4110 by an interrupt signal from hardware (not shown). In response to the print completion from the image manager 4110, the sync manager 4080 notifies the print manager 4090 of the print completion. The print manager 4090 receives the completion of paper discharge from the printer unit, returns an end notification to the job manager 4040, and the job manager 4040 returns it to the copy application unit 4020 via the common interface 4030. The copy application unit 4020 notifies the UI control unit of the end of the job when scanning and printing are completed.

  In the case of a PDL data development storage job, a request from the host PC that has input the PDL print is transmitted to the PDL application 4023 via the network application 4120. The PDL application instructs the job manager 4040 via the common interface 4030 for a PDL data development storage job. At this time, the PDL manager 4070 and the store manager 4100 receive a request from the job manager 4040.

  The PDL manager 4070 makes a PDL data transmission request to the host PC via the network application 4120. At the same time, an image processing request for PDL expansion storage is issued to the image manager 4110 via the sync manager 4080.

  The image manager 4110 sets the RIP 2018 in accordance with an instruction from the PDL manager 4070. When the setting is completed, the completion of preparation for PDL development is notified via the sync manager 4080.

  Thereafter, the PDL manager 4070 instructs the host PC to start transmitting PDL data.

  The RIP 2018 receives the PDL code from the host computer via the network 2007, and the CPU 2001 stores the PDL code in the RAM 2002 through the system bus 2008. The CPU 2001 converts the PDL into an intermediate code, inputs it again to the RIP 2018 via the system bus 2008, and develops it into a bitmap image (multi-value). In the present embodiment, the RIP 2018 expands the intermediate code into a 1200 dpi bitmap image.

  Thereafter, the resolution of the image data is lowered by high-definition resolution conversion 2054. In this embodiment, 1200 dpi data is converted into a 600 dpi signal. This is a technique that enables conversion to 600 dpi data while maintaining phase information of an image of 1200 dpi, and even if the output is 600 dpi in terms of character (font) and line ratio (proportion). It is processed so as to have the expressive power of the resolution level of.

  Thereafter, the image data compressed in the compression 2012 is accumulated in the RAM 2002 by the DMAC 2009 via the ImageBufI / F2011.

  The completion of the PDL data expansion is transmitted to the image manager 4110 from the RIP 2018.

  Upon receiving the PDL data expansion completion from the image manager 4110, the sync manager 4080 notifies the PDL data expansion completion to the PDL manager 4070 and the print manager 4090. At the same time, the sync manager 4080 instructs the image manager 4110 to file the compressed image stored in the RAM 2002 into the HDD 2004.

  The store manager 4100 stores the image (including the character / photo determination signal) on the memory in the HDD 2004. Color / monochrome information is stored in an SRAM (not shown) as image accompanying information, and attribute information such as a PDL image, a color space CMYK or RGB, and an image resolution of 1200 dpi is stored as an image input source. When the storage of the PDL image in the HDD 2004 is completed, a storage completion notification is received from the sync manager 4080 and is notified to the PDL application 4023 via the common interface 4030. After this notification, the PDL application 4023 notifies the network application 4420 of completion of storage in the HDD, and this information is transmitted to the host PC that has entered the PDL print. In the case of a PDL print job, an image developed on the memory is printed by the PDL manager 4070 and the print manager.

  To print an image stored in the PDL format, a stored document instructed to be printed by the UI is issued as a print job to the BOX application. The BOX application unit 4022 inputs a print job to the job manager 4040 via the common interface 4030. Unlike local copy, the file read manager 4060 receives a request from the job manager 4040 instead of the scan manager 4050. A request for expanding an image instructed to be printed from the HDD to the memory is made to the image manager 4110 via the sync manager 4080.

  The subsequent printing operations are the same as those of a remote copy print job, which will be described later, and will not be described.

  In the case of a remote copy scan job or transmission job, the store manager 4100 receives a request from the job manager 4040 instead of the print manager 4090. When the scan image has been stored in the HDD, a storage completion notification is received from the sync manager 4080, and this is notified via the common interface 4030 to the copy application unit 4020 for remote copying and to the transmission application unit 4021 for transmission jobs. After this notification, the copy application unit 4020 and the transmission application 4021 request the network application 4420 to transmit the file stored in the HDD. The network application 4420 that has received the request transmits the file.

  The network application 4420 receives setting information related to copying from the copy application unit 4020 at the start of the job, and also notifies the remote device of the setting information. In the case of remote copy, the network application 4420 performs transmission using a device-specific communication protocol.

  In the case of a transmission job, the image manager 4110 is requested to perform necessary image processing (color space conversion, scaling), and a standard file transfer protocol such as FTP or SMB is used for the converted image.

  In the case of fax transmission, after the file is stored, the transmission application 4021 instructs the FAX manager 4041 to transmit via the common interface 4030 and the job manager 4040. The FAX manager 4041 negotiates with the counterpart device via the Modem 2050, requests the image manager 4110 to perform necessary image processing (color-> black and white color space conversion, multi-value binary conversion, rotation, scaling), and after conversion. Is sent using Modem.

  If there is a printer at the transmission destination, the transmission application issues a print instruction as a print job via the common interface 4000. The operation at that time is the same as that of the remote copy print job described below. When the transmission destination is a box destination in the device, the file store manager 4100 stores it in the file system in the device.

  Hereinafter, a change in image processing according to a transmission destination, which is characteristic control in the present invention, will be described.

  Although control is performed in the transmission job, when the image data to be transmitted is input from the scanner, there is no problem with the above-described control.

  However, when the image data to be transmitted is obtained by PDL development, the image data is presumed to be printed by a 600 dpi electrophotographic printer by the high-definition resolution conversion 2054, and is optimized for the above-described image data. Resolution conversion processing is performed by an algorithm. This high-definition resolution-converted image data has no problem when it is printed on a 600 dpi electrophotographic printer by a remote copy job or the like, but when it is transmitted to another PC by a transmission job, an image with a broken gradation is obtained. As a result, the intended image quality cannot be obtained.

  Specifically, when resolution conversion is performed from 1200 dpi to 600 dpi by the high-definition resolution conversion 2054 described above, the character edge portion of the image tries to retain the pixel and attribute information of 1200 dpi as much as possible, so that only the width of the edge portion has a width. It will be stored widely. The 600 dpi electrophotographic engine does not print by appropriately switching the gamma table or the like at the time of printing according to the attribute information, but ignores the attribute information and displays it as simple raster image data, for example, on a PC display. When the image is viewed, the image becomes blurred as if the character edge portion is smoothed.

  In order to prevent this, when image data subjected to high-definition resolution conversion processing is transmitted to another PC or the like, the following image processing may be performed via an image manager before transmission. In other words, the color space conversion 2021 is used to pass the LUT having a steep slope only for the character part of the original image that has been processed by the LUT in accordance with the attribute information, or that has undergone smoothing processing. Thus, the edge portion of the character is restored. It is not necessary to perform special processing for the non-character portion (the through LUT may be passed, see FIG. 30).

  Similarly, when performing fax transmission, the above-described LUT processing may be performed when color-> black-and-white color space conversion is performed.

  As described above, when transmitting PDL developed image data that has been subjected to high-definition resolution conversion, edge restoration processing by LUT is performed in accordance with the transmission destination (printer, other PC, or fax). By switching whether or not, the image data that has been subjected to high-definition resolution conversion at the time of printer output is sent to the printer as it is, so that an output equivalent to 1200 dpi can be obtained while the printer resolution is 600 dpi, and the image data can be transferred to another PC. At the time of transmission, it is possible to transmit an image having an appropriate quality with the edge restored. Furthermore, due to the high-definition resolution conversion processing, the PDL decompressed data has a resolution of 600 dpi while having an image quality equivalent to 1200 dpi, so that the memory, CPU power, HDD transfer speed, etc. required for handling are 600 dpi images. It can be the same.

  At the time of FAX reception, the FAX manager receives an image using Modem and stores it in the HDD 2004 as an image file. When the box application 4021 is notified after the HDD 2004 is stored, a reception print instruction is issued from the box application 4021 to the job manager 4040 via the common interface 4030. Thereafter, the operation is the same as a remote copy print job, which will be described later, and a description thereof will be omitted.

  In the case of a remote copy print job, the network application 4420 saves an image from the transmission side in the HDD and issues a job to the copy application unit 4020. The copy application unit 4020 submits a print job to the job manager 4040 via the common interface 4030. Unlike local copy, the file read manager 4060 receives a request from the job manager 4040 instead of the scan manager 4050. A request for expanding the received image from the HDD to the memory is sent to the image manager 4110 via the sync manager 4080. The image manager 4110 expands the image in the memory. When the development is completed, the image manager 4110 notifies the file read manager 4060 and the print manager 4090 of the completion of the development via the sync manager 4080. When an image is stored in the memory, the print manager 4090 selects a paper feed stage designated by the job manager or a stage having the paper size via the device I / F, and issues a print request. In the case of automatic paper, a paper feed stage is determined from the image size and a print request is issued. At the same time, a print image processing request is sent to the sync manager 4080. Upon receiving a request from the print manager 4090, the sync manager 4080 requests the image manager 4110 to set print image processing. (At this time, for example, if the optimum size paper runs out and rotation is necessary, a rotation instruction is also requested. If there is a rotation instruction, the image manager rotates the image using the image rotation 2019.) The image manager 4110 The printer image processing unit 2016 is set, and a print preparation completion is notified to the print manager 4090 via the sync manager 4080. The print manager 4090 issues a print instruction to the printer. The completion of print image transfer is transmitted to the image manager 4110 by an interrupt signal from hardware (not shown). Upon receiving the print completion from the image manager 4110, the sync manager 4080 notifies the file read manager 4060 and the print manager 4090 of the print completion. The file read manager 4060 returns an end notification to the job manager 4040. In response to the completion of paper discharge from the printer unit, the print manager 4090 returns an end notification to the job manager 4040. The job manager 4040 returns an end notification to the copy application unit 4020 via the common interface 4030. The copy application unit 4020 notifies the UI control unit of the end of the job when scanning and printing are completed.

  As described above, according to the invention corresponding to the present embodiment, the image processing method is automatically switched using an LUT or the like according to the output destination of the bitmap data that has been PDL-developed. An output with a good image quality will be made.

  In the present invention, a storage medium recording software program codes for realizing the functions of these embodiments is supplied to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus stores the storage medium in the storage medium. It is also achieved by reading and executing the programmed program code.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments and modifications, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a DVD-ROM, a DVD-RAM, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, A ROM or the like can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. A case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing is also included.

  Further, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted in the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. This includes a case where the CPU or the like provided in the card or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

The functional block diagram which shows an example of a structure of the high-definition resolution conversion part 2054 corresponding to embodiment of this invention Functional block diagram for explaining resolution conversion processing of an image area signal according to the present invention The functional block diagram which shows an example of a structure of the luminance density conversion part corresponding to embodiment of this invention Functional block diagram showing an example of the configuration of the product-sum operation processing unit 106 corresponding to the embodiment of the present invention The functional block diagram which shows an example of a structure of the mask selection signal generation part 108 corresponding to embodiment of this invention. Functional block diagram for explaining the L conversion unit 107 corresponding to the embodiment of the present invention The functional block diagram which shows an example of a structure of 8/4 conversion part 401 grade | etc., Corresponding to embodiment of this invention Functional block diagram showing an example of the configuration of the inversion processing unit 404 and the like corresponding to the embodiment of the present invention Functional block diagram showing an example of the configuration of the 4/3 conversion unit 407 and the like corresponding to the embodiment of the present invention Functional block diagram showing an example of the configuration of the area determination unit 410 corresponding to the embodiment of the present invention The functional block diagram which shows an example of a structure of the 8/1 conversion part and ZSG selection part corresponding to embodiment of this invention The figure for demonstrating the bit converter corresponding to embodiment of this invention The functional block diagram which shows an example of a structure of the ON / OFF signal switching signal generation part corresponding to embodiment of this invention Functional block diagram showing an example of the configuration of the SWAP unit 414 corresponding to the embodiment of the present invention The figure which showed the example of a setting of each mask register corresponding to embodiment of this invention Diagram showing the overall configuration of the image forming system The figure which shows the whole structure of an image forming apparatus Relationship between packet image and whole image Diagram showing structure of packet image Block diagram of scanner image processing of the present invention Block diagram of printer image processing of the present invention External view of input / output device of image forming apparatus External view of the operation unit of the image forming apparatus Explanatory drawing of the transmission screen of the operation part of this invention Detailed explanatory diagram of the transmission screen of the operation unit of the present invention Explanatory drawing of the copy screen of the operation unit of the present invention Explanatory drawing of the box screen of the operation unit of the present invention Detailed explanatory diagram of the box screen of the operation unit of the present invention Software configuration diagram showing the software configuration of the present invention The figure explaining the principle of the density conversion of the character part non-character part of this invention

Explanation of symbols

200 Image forming apparatus 220 Image forming apparatus 230 Image forming apparatus 240 Personal computer 2000 Controller Unit
2011 LAN
2012 Operation unit 2070 Scanner unit 2095 Printer unit 2200 Controller Unit
2212 Operation unit 2270 Scanner unit 2295 Printer unit 2300 Controller Unit
2312 Operation unit 2370 Scanner unit 2395 Printer unit

Claims (2)

Image information input means for inputting image information;
Image information storage means for temporarily storing the input image information;
Image information output means capable of printing a color image using a plurality of toners;
Image information storage means for storing at least one or more input image information for a certain period;
Image information transmitting means for transmitting the image information to an external device connected via a network;
Image information receiving means for receiving the image information from an external device connected via a network;
Control means for controlling the image information input means, the image information storage means, the image storage means, the image information output means, the image information transmission means, and the image information reception means;
In an image processing apparatus comprising:
First resolution conversion means for performing resolution conversion on the image information input by the image information input means;
Second resolution conversion means for performing resolution conversion on the image information input by the image information input means;
Density conversion means for performing density conversion on the image information input by the image information input means;
When transmitting the image information converted by the first resolution converting means by the image information transmitting means, the image information is subjected to resolution conversion by the second resolution converting means, or by the density converting means. Switching means for switching between density conversion,
A switching control means for automatically switching the switching means according to a transmission destination transmitted by the image information transmission means;
An image processing apparatus comprising: The first resolution conversion means converts first image data having a first resolution N into second image data having a second resolution M lower than the first resolution, and outputs the second image data. There,
A position of a target pixel in the first image data is determined according to a ratio of the second resolution M to the first resolution N, and based on a pixel value in a predetermined region determined by the target pixel. Processing means for generating and outputting a plurality of pixel values,
Selection signal generating means for generating a selection signal in accordance with the value of the target pixel and an attribute signal representing an attribute relating to the target pixel;
An output unit that selects the plurality of pixel values generated by the processing unit using the generated selection signal and outputs the selected pixel value as the second image data;
The image processing apparatus according to claim 1, further comprising:

Images