JP2006086627A - Image processing apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit a selected image to a PC at the same time when reading of one page is finished even when a read instruction is received by chromatic/achromatic automatic determination and freely select the gradation of an RGB image and the gradation of a monochromatic image in transferring the image to a controller. <P>SOLUTION: The image processing apparatus includes an image read section for reading an original image; a chromatic/achromatic determination section 303 for discriminating whether the read image is a chromatic image or an achromatic image; a color correction section 304; and a binary processing section 315; an image selection section 316 for selecting whether a full color image is outputted to an external I/F or a monochromatic binary image is outputted to the external I/F in response to a chromatic/achromatic discrimination result informed at the same time when the RGB image from the image read section and the monochromatic binary image generated by the binary section 315 are transferred to a controller at the same time, and noninverting/inverting sections 317 to 320 capable of inverting the gradation before the images are transferred to the controller, which switches the gradation of the RGB image and the monochromatic binary image. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus having an engine unit such as a color scanner, a monochrome plotter, or a color plotter, and in particular, an image processing apparatus that performs image processing based on a chromatic / achromatic determination result of an image read by a color scanner, and The present invention relates to an image forming apparatus including the image processing apparatus.

  As a conventional technique, for example, a method of performing original chromatic / achromatic determination by a pre-scanless method and switching image forming processing according to the determination result has been proposed. One of them is the invention disclosed in Patent Document 1. In the present invention, when the ADF is used in each mode, the carriage of the image scanner is moved in advance to a position where the original can be read as close to the normal position as possible, and the original is chromatic or achromatic while the original is being fed. After the determination, the carriage is quickly returned to the normal position, and either a sequence operation for only a specific color or a full color sequence operation is executed according to the result.

As other related techniques, for example, the inventions disclosed in Patent Documents 2 and 3 are also known.
JP 9-172550 A JP 2001-251511 A JP-A-10-336466

  However, in recent years, in black and white copiers or color copiers having a color scanner, there is an increasing number of cases where a scanner function is used from a PC or the like through an external I / F. The image requested by the PC includes RGB full color, monochrome gray scale, monochrome binary, RGB binary, single color, and the like. The read image instruction method includes setting the type of image and selecting the read image automatically using the chromatic / achromatic determination result.

  Here, when a method for automatically selecting a read image using a chromatic / achromatic determination result is instructed from the PC, for example, an RGB full-color image is read if chromatic, and a monochrome binary image is read if achromatic. At the time of setting, in the conventional prescanless method, after reading an RGB full-color image with a scanner and storing it in a memory, the chromatic / achromatic determination result is waited. Then, a monochrome binary image is created from the stored RGB image by software processing and transferred to the PC. The reason for such a procedure is that since it is a pre-scanless method, it can be determined whether the image being read is chromatic or achromatic, until the worst one page is read. .

  As described above, in the conventional method, software intervenes in the middle of image processing, so that it takes extra time for image processing. As for the binarization method, binarization is performed with a fixed threshold value for the entire page, binarization with a dither method (variation threshold), binarization with error diffusion, and switching between binarization methods with a picture / character part. However, it takes more time for the software to perform these processes than for hardware. Conventionally, since picture / character separation information has not been given to software, a monochrome binary image with higher image quality cannot be obtained.

  Furthermore, when an image is output to the outside, the RGB full color has a large image data capacity, so the JPEG format is often used. Monochrome grayscale and monochrome binary images have a relatively small image data capacity. Since lossless compression is suitable, the image format is often the TIFF format. Further, the image logic is handled by luminance data for RGB images and is handled by density data for monochrome images in consideration of the case where it is used for Internet FAX using the TIFF format. Thus, the gradation of the RGB image and the gradation of the monochrome image are often different.

  The present invention has been made in view of such a background, and an object of the present invention is to transmit a selected image to a PC simultaneously with completion of reading of one page even when a reading instruction is received in chromatic / achromatic automatic determination. It is possible to freely select the gradation of the RGB image and the gradation of the monochrome image at the time of transfer to the controller.

  To achieve the object, the first means includes an image reading means for reading a document image, a means for determining whether the image read by the image reading means is a chromatic image or an achromatic image, A means for creating a monochrome gray scale from the RGB image read by the image reading means, a means for binarizing after performing predetermined image processing on the RGB image read by the image reading means, and control of each means In the image processing apparatus having the control means, the RGB image read by the image reading means and the monochrome binary image created by the binarization unit are simultaneously transferred to the control means and are notified at the same time. Means for switching whether to output a full-color image to the external I / F or a monochrome binary image to the external I / F according to the achromatic / achromatic determination result; Characterized in that it comprises a means for inverting the gradation of an RGB image the monochrome binary image for each color before transferring to the serial controller.

  According to a second means, in the first means, the switching means receives the RGB image read by the image reading means by the control means when receiving a scanner reading instruction via the external I / F. A monochrome binary image binarized by the binarizing means is transferred.

  A third means is the first or second means, wherein the means for inverting the gradation is the RGB by changing the table of a γ correction means provided for each image path of the RGB image and the monochrome grayscale image. The gradation of the image and the monochrome binary image is switched for each color, and the RGB image and the monochrome binary image are simultaneously transferred to the control means.

  According to a fourth means, in the first or second means, the means for inverting the gradation is a step of the monochrome binary image by inverting the binarization threshold determination condition in the binarization means. The tone is inverted and transferred to the control means simultaneously with the RGB image.

  The fifth means is characterized in that the image forming apparatus includes the image processing apparatus according to any one of the first to fourth means.

  A sixth means for determining whether the original image is a chromatic image or an achromatic image, and performing image processing according to the result; a first step of reading the original image by the image reading means; First step: a second step of determining whether the read image is a chromatic image or an achromatic image; a third step of creating a monochrome gray scale from the RGB image read in the first step; , A fourth step of performing binarization after performing predetermined image processing on the RGB image read in the first step, and an RGB image read in the first step and 2 in the fourth step. A full-color image is output to an external I / F or a monochrome binary image is output to an external I / F according to a chromatic / achromatic determination result simultaneously transferred to a binarized monochrome binary image and notified simultaneously. Switch the output It and a fifth step of switching the gradation of an RGB image the monochrome binary image for each color before sending characterized.

  According to the present invention, an RGB image is read and transferred to the memory of the controller, and at the same time, a monochrome binary image binarized by hardware by the binarization unit or a monochrome grayscale image created by the color correction unit In addition, even if a reading instruction is received in the chromatic / achromatic automatic determination, the selected image can be sent to the PC at the same time as reading of one page is completed. At the time of transfer, the gradation of the RGB image and the gradation of the monochrome image can be freely selected.

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

FIG. 1 is a block diagram showing a schematic configuration of an image processing apparatus according to an embodiment of the present invention.
In the figure, an image processing apparatus 100 has a configuration in which an engine unit 110 that performs image formation and a controller 120 that controls the entire image forming apparatus are connected by a bus 140. The engine unit 110 includes a CPU 111 that controls the engine unit 110, an image reading unit 112 that includes a scanner that reads a document, an image recording unit 113 that includes a plotter that forms an image on a transfer material, image processing, CPU I / ASIC-E114 for controller etc. which incorporate F, PCIII / F, etc. are provided. The ASIC-E 114 serves as an interface between the image processing unit (scanner image processing unit 115 and printer image processing unit 116) that performs shading correction, MTF correction, γ correction, and the like on the image data from the image reading unit 112 and the bus 140. The image I / F unit 117 functions.

  The controller 120 includes an operation unit 121 that performs processing and operation settings of the image forming apparatus, an HDD 122 that accumulates image data, a CPU 123 that controls the entire image forming apparatus, an operation unit I / F, a CPU I / F, a PCI II / F, a memory The controller ASIC-C 124 with a built-in controller, a local memory (MEM-C) 127 and (MEM-P) 129, and an interface (AGP) 141 NB 128 connected to the ASIC-C 124, etc. The ASIC-C 124 is also provided with a rotator 125 that rotates image data to a desired angle and an editor 126 that performs image composition, scaling, and the like. The controller 120 is further provided with a communication ASIC 130 for capturing image information from the outside, options 131 and 132, SB 133, ROM 134, and the like.

  FIG. 2 is a block diagram showing details of the engine unit 110 of FIG. In the figure, the image processing unit includes a scanner image processing unit 115 and a printer image processing unit 116. The scanner image processing unit 115 receives RGB read data from the CCD 200, converts the data into CMYK data, and converts the image I / O into image data. The data is output from the F unit 117 to the ASIC-C of the controller 120. On the other hand, CMYK print data read from the HDD 122 and subjected to rotation processing and editing processing is input to the printer image processing unit 116 from the ASIC-C 124 of the controller 120, and the CMYK color image data is input to the printer image processing unit 16. LDBs 210, 211, 212, and 213 are written, and laser writing is performed for each color on the surface of a photosensitive drum 402 described later to form a latent image.

FIG. 3 is a block diagram showing a detailed configuration of the scanner image processing unit 115. Hereinafter, it demonstrates with operation | movement.
In the image processing apparatus 100 configured as shown in FIGS. 1 to 3, an image is read from the image reading unit 112 of the image processing apparatus 100, and the shading correction unit 300, the filter processing unit 302, and the pixels shown in FIG. A picture / character separation unit 301 that separates images, a chromatic / achromatic determination unit 303 that determines whether an image is chromatic or achromatic, a conversion from an RGB image into a CMYK image, or a monochrome grayscale image generation. A color correction unit 304; scaling units 305 to 309 that perform resolution conversion and image size change; γ correction units 310 to 313 for each color plate that perform γ correction for CMYK (RGB and gray scale); RGB images and gray scales; A binarization unit 315 that performs binarization processing, a packing unit 314 that packs binarized K, a binarization unit 315, and a packing unit 3 14 and the CMYK image data corrected and scaled and γ corrected by the color correction unit 304 and an image selection unit 316 that selects an image to be output to the controller. The data is stored in the memory (MEM-C) 127 of the controller 120 via the scanner image processing unit 115 having functions such as normal rotation / inversion units 317 to 320 for switching the rotation / inversion. At the time of printing operation, the image stored in the controller 120 is transferred to the printer image processing unit 116 through the image I / F unit 117, subjected to printer γ correction, gradation processing, and frame processing, and then in the image recording unit 113. Printed on recording paper. When performing a scanner operation upon receiving an instruction from a PC or the like, the instruction is received from the PC via an external I / F for connecting to a host such as a network, USB, or IEEE1394, and an image is read from the image reading unit 112. After each of the above image processing, it is stored in the memory 127 of the controller via a general-purpose bus such as PCI or an image I / F unit such as a video I / F, and converted into image data such as TIFF format or JPEG format by the CPU. Is transmitted from the external I / F unit to the PC. At this time, the RGB image is often converted in the JPEG format, and the monochrome image is often converted in the TIFF format.

  FIG. 4 is a timing chart showing the relationship between LGATE, FGATE, LSYNC and DATA when reading a document.

  FIG. 5 is a flowchart showing an operation procedure of a scanner reading operation performed conventionally, and FIG. 6 is a flowchart showing an operation procedure of the scanner reading operation in the present embodiment.

  In FIG. 6, when the ACS mode (Auto Color Select-mode in which the read image is chromatic / achromatic and the type of the read image is switched) is selected as the reading mode from the PC (step S101-YES), the image reading unit The RGB image read at 112 is filtered, and the color correction unit 304 generates a monochrome grayscale image (step S102). The RGB image and the monochrome grayscale image are subjected to scaling processing by the scaling units 305 to 309 when the resolution is converted or the image size is enlarged or reduced, and the γ correction units 310 to 313 convert the images according to the texture and characteristics of the document. to correct. The processed image is passed to the image selection unit 316 and the binarization unit 315. In the binarization unit 315, binarization with a fixed fixed threshold value, binarization by the dither method, binarization by the error diffusion method, binarization by the dither & error diffusion method, and extraction by the picture / character separation unit 301 By using the separated signal SEP, a binarized image is generated by switching between a fixed threshold when the pixel is a character portion and a dither method, an error diffusion method, and a dither & error diffusion method when the pixel is a picture portion. To do. If the image selection unit 316 is instructed to select the monochrome monochrome value in the ACS mode, the RGB full-color image (R, G, B) and the monochrome binary image (binary) from the binarization unit are displayed. A total of four systems are selected (step S103). An example of an output format in the image selection unit 316 is shown in FIG.

  Next, it is selected whether or not to invert the gradations for the four systems of images selected by the gradation normal rotation / inversion unit. Here, when the monochrome image is changed to density data due to the advantage of being used for Internet FAX, the gradation is inverted from the monochrome image of the brightness data created from the RGB image as the brightness data, and the density data is changed. In addition, gradation inversion is not performed if the luminance data remains unchanged. The monochrome image thus converted and the RGB image of luminance data are simultaneously transferred to the memory of the controller 120. In addition, when it is instructed to select an achromatic monochrome gray scale in the ACS mode, a total of 4 systems of RGB full color images (R, G, B) and monochrome gray scale (GS) from the color correction unit 304 are selected. Then, only the monochrome gray scale is inverted, and simultaneously transferred to the memory of the controller 120 (step S104), and stored in the memory 122 of the controller 120 (step S105).

  In the controller 120, based on the determination result acs_flag from the chromatic / achromatic determination unit 303 that has been determined by the end of the transfer of one page, if it is chromatic (step S106—YES), the RGB full-color image is converted into a JPEG image. Data or TIFF image data is created (step S107), and if it is achromatic, TIFF image data is created from a monochrome grayscale image or monochrome binary image transferred simultaneously with the RGB image (step S108) and transmitted to the PC. (Step S109). With this configuration, it is not necessary to generate a binarized image or a grayscale image and select a gradation by software after being stored in the controller, and the response time to the CPU load and the PC can be shortened.

  On the other hand, when the ACS mode is not designated as the reading mode in step S101 (step S101-NO), the user sets the type of image to be read from the operation unit 121 (step S110), and the setting result is the scanner image processing. The scanner 115 is notified, and the scanner reads the set image type (step S111), stores the read image data in the memory 121 of the controller 120 (step S112), and transfers the stored image data to the PC (step S112). S109).

  Conventionally, as shown in FIG. 5, the processing from step S102 to step S109 reads an RGB full-color image with a scanner (step S121), and the read image data is stored in the memory of the controller (step S122). If the image is chromatic, the data stored in step S122 is transferred to the PC (step S109). If the image is achromatic, the monochrome gradation is selected by software, and a binary binary image is obtained by binarization processing. Alternatively, a monochrome gray scale image is created by color correction processing (step S124) and transferred to the PC (step S109). Therefore, since software intervenes in the middle of image processing, it takes extra time for image processing. As for the binarization method, binarization is performed with a fixed threshold for the entire page, binarization with a dither method (variation threshold), binarization with error diffusion, and binarization method with a pattern / character part. It is obvious that if these processes are performed by software, it takes more time than hardware.

  In the conversion to the gray scale, a gray scale is obtained by setting a γ table in which only the gray scale version is inverted as shown in FIG. 8 among the γ correction sections prepared for each color plate. Is converted to density data. In addition, a monochrome binary image is generated from the converted gray scale. Four systems are selected from these image data as described above, and are simultaneously transferred to the memory of the controller 120. The processing on the controller 120 is the same as described above.

  Further, when a monochrome binary image is created from grayscale, the condition to be determined by the binarization threshold is logically inverted as shown in FIG. 9, and the luminance data is converted to density data, and the resulting monochrome binary image is obtained. And the RGB image are simultaneously transferred to the memory of the controller 120. The processing on the controller 120 is the same as described above.

  FIG. 10 is a diagram showing a schematic configuration of a color printer as a color image forming apparatus according to an embodiment of the present invention. In FIG. 10, the color printer basically includes an image forming unit 10, a paper feeding unit 20, a fixing unit (device) 30, and a paper discharge unit 40.

  The image forming unit 10 includes CMYK photosensitive drums 11C, 11M, 11Y, and 11K, writing units for each color (not shown) that perform optical writing on the photosensitive drums 11C, 11M, 11Y, and 11K, Contact with the body drums 11C, 11M, 11Y, and 11K, and face each of the photosensitive drums 11C, 11M, 11Y, and 11K with the transfer belt 12 sandwiched between the driving pulley and the driven pulley. The transfer roller 13C, 13M, 13Y, 13K provided at the position where the transfer is performed, and the transfer roller 14 provided downstream of the black transfer portion and sandwiching the vertical conveyance path 15 are mainly configured.

  The sheet feeding unit 20 conveys the first and second sheet feeding trays 21 and 22 and the transfer sheets 25 and 26 fed from the sheet feeding trays 21 and 22 by the sheet feeding rollers 23 and 24 to the vertical conveyance path 15. For this purpose, the transfer paper conveyance path 16 is provided, and a manual feed tray 27 is provided for manually feeding the transfer paper to the vertical conveyance path 15.

  The fixing device 30 is provided on the downstream side of the longitudinal conveyance path 15 in the conveyance direction of the transfer sheet, and includes a fixing roller 31, a heating roller 32, a fixing belt 33, and a pressure roller 34.

  The paper discharge unit 40 is provided on the downstream side of the fixing device 30 in the transfer paper conveyance direction, and includes a paper discharge roller 41 and a paper discharge tray 42.

  In the color printer configured as described above, the transfer paper fed from the paper feed trays 21 and 22 or the manual feed tray 27 is sent to the vertical conveyance path 15 and is formed by the image forming unit 10 that performs development and transfer. The full-color image superimposed on the surface of the transfer belt 12 is transferred onto the transfer paper by the transfer roller 14. The unfixed image transferred onto the transfer paper is sent to a fixing device 30 and is formed by a fixing roller 31 and a pressure roller 34 which are driven and driven inside a fixing belt 33 whose surface is heated by a heat source such as a heater. As a result, the sheet is fixed on the surface of the transfer paper and becomes a semi-permanent image, and is discharged onto the paper discharge tray 42.

  As described above, according to the present embodiment, the RGB image read by the image reading unit, the monochrome grayscale image generated by the color correction unit from the RGB image, and the monochrome binary image generated by the binarization unit are obtained. Select by the image selection unit, perform normal rotation / reversal of gradation for each color plate by the gradation normal rotation / reversal unit, and transfer monochrome binary images or monochrome grayscale images to the controller simultaneously with RGB full-color images Therefore, on the basis of the chromatic / achromatic determination result that is determined by the end of reading one page, it is possible to select whether to select an RGB full-color image or a monochrome image until the worst one page is read. And desired gradation data suitable for the image format of the TIFF format or the JPEG format can be obtained. This eliminates the need for post-processing such as binarization and monochrome grayscale creation by software, reducing the load on the CPU and shortening the response time to the PC.

1 is a block diagram illustrating a schematic configuration of an image processing apparatus according to an embodiment of the present invention. It is a block diagram which shows the detail of the engine part of FIG. FIG. 2 is a block diagram illustrating a detailed configuration of a scanner image processing unit in FIG. 1. FIG. 6 is a diagram illustrating document reading timing. It is a flowchart which shows the conventional reading procedure. It is a flowchart which shows the reading procedure which concerns on embodiment of this invention. It is a figure which shows the output format in an image selection part. It is a figure which shows the example of (gamma) table at the time of (gamma) conversion. It is a figure which shows the example of binarization determination conditions. 1 is a diagram illustrating an example of an image forming apparatus including an image processing apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image processing apparatus 110 Engine part 111,123CPU
112 Image reading unit 113 Image recording unit 114 ASIC-E
115 Scanner Image Processing Unit 116 Printer Image Processing Unit 120 Controller 121 Operation Unit 122 HDD (Memory)
124 ASIC-C
300 shading correction unit 301 picture / character separation unit 302 filter processing unit 303 chromatic / achromatic determination unit 304 color correction unit 306 to 309 scaling unit 310 to 313 gamma correction unit 315 binarization unit 316 image selection unit 317 to 320 positive Roll / reverse part

Claims (6)

Image reading means for reading a document image;
Means for determining whether the image read by the image reading means is a chromatic image or an achromatic image;
Means for making a monochrome gray scale from the RGB image read by the image reading means;
Means for binarizing after performing predetermined image processing on the RGB image read by the image reading means;
Control means for controlling each means;
In an image processing apparatus having
The RGB image read by the image reading means and the monochrome binary image created by the binarization unit are simultaneously transferred to the control means, and a full color image is obtained according to the chromatic / achromatic determination result notified at the same time. Means for switching between outputting to an external I / F or outputting a monochrome binary image to the external I / F;
Means for inverting the gradation of the RGB image and the monochrome binary image for each color before transferring to the control means;
An image processing apparatus comprising:   The switching means is a monochrome 2 binarized by means of binarizing the RGB image read by the image reading means to the control means when receiving a scanner reading instruction via an external I / F. The image processing apparatus according to claim 1, wherein a value image is transferred.   The means for inverting the gradation switches the gradation of the RGB image and the monochrome binary image for each color by changing the table of the γ correction means provided for each image path of the RGB image and the monochrome grayscale image. The image processing apparatus according to claim 1, wherein the RGB image and the monochrome binary image are simultaneously transferred to the control unit.   The means for inverting the gradation inverts the gradation of the monochrome binary image by inverting the determination condition of the binarization threshold in the binarizing means, and transfers the same to the control means simultaneously with the RGB image. The image processing apparatus according to claim 1, wherein:   An image forming apparatus comprising the image processing apparatus according to claim 1. In an image processing method for determining whether a document image is a chromatic image or an achromatic image and performing image processing according to the result,
A first step of reading a document image by an image reading means;
A second step of determining whether the image read in the first step is a chromatic image or an achromatic image;
A third step of creating a monochrome gray scale from the RGB image read in the first step;
A fourth step of binarization after performing predetermined image processing on the RGB image read in the first step;
The RGB image read in the first step and the monochrome binary image binarized in the fourth step are transferred at the same time, and a full color image is externally output according to the chromatic / achromatic determination result notified at the same time. A fifth step of switching whether to output to the I / F or outputting a monochrome binary image to the external I / F, and switching the gradation of the RGB image and the monochrome binary image for each color before the transfer;
An image processing method comprising:

Images