RU2154916C2 - Method and device for image data scanning in image processing system - Google Patents

Abstract

FIELD: image processing systems. SUBSTANCE: device has roller for document feeding, detector, which is in close contact to roller, white sheet between roller and detector, image processor, which converts analog signal, which is sent by detector, into digital signal, memory unit, which stores data used for correction of shadow error, and controller for storage of data, which are read from white sheet in recording mode using correction of shadow error. Goal of invention is achieved by design of roller, which is black, and design of detector, which is designed as contact image reader for reading document in scanning mode. Data, which are read from white sheet in recording mode are designed as digital signal, which is transmitted through image processor. In addition, controller is used for detection of white and black selection level in comparison to initially read document data, depending on shadow error correction data, which are stored in memory unit in scanning mode. Also, controller is used for generation of next read document data as white or black depending on selection of white or black level. EFFECT: possibility to store shadow error correction data in recording mode and to use them for next document scanning. 2 cl, 6 dwg

Description

 The present invention relates to an image processing system, and more specifically, to a device and method for using standard original image data stored in accordance with a white document as data for correcting distortion due to shading.

State of the art
Figure 1 shows a typical relationship between a light source and a charging-coupled device (CCD for short) or a contact image sensor (CDI for short).

The light from the light source is projected at an angle of 45 ^° onto the document, and the light reflected on the white roller or white strip behind the document is converted into an electrical signal through the lens using a CCD or CDI, so that the scan data is generated in accordance with the converted electrical signal.

 To compensate for the difference in lighting in accordance with the characteristics of a fluorescent lamp, halogen lamp and a number of light emitting diodes, etc., a waveform was proposed as a light source for correcting shading distortion using light reflected on a white roller or white strip before scanning a document.

 In FIG. 2 presents a flowchart for scanning image data in a known image processing system.

 The image processing system is equipped with a sensor element of an automatic document feeder (ASPD) for determining whether a document is present or not, and a read position sensor (DPS) for detecting the beginning and end of a document. Behind the ASPD sensor is the DPS sensor, and the scan point is located behind the DPS.

 At step 211, it is determined whether the document is present or not. If it is determined in step 211 that the document is present, i.e. when the ASPD sensor is turned on or when the document is inserted on the substrate, the program proceeds to step 212, which drives the electric drive to feed the document. As long as the DPS is turned on, the document is continuously fed. If the DPS is turned on at step 213, the light source is turned on at step 214.

 The light reflected on the white roller or white strip from the light source is converted into an electrical signal by means of a CCD or CDI, and at step 215, data is created and stored to correct the shading distortion of the paper sheet. At step 216, a black and white selection level is determined and stored in the database for correcting shading distortion. At this time, if the electric signal of the light reflected on the white roller or white strip from the light source is high, white data is selected, and if the electric signal of the light reflected on the white roller or white strip from the light source is zero, the black data is selected. The standard for selecting white data or black data is the level of black and white selection.

 In the next step 217, the document is fed to the scanning point, and scanning begins. The program proceeds to step 218, where one line of the document is read and black and white data is generated based on the black and white selection level. The program in step 218 runs continuously while the DPS is on. If the DPS is turned off at step 219, the program proceeds to step 220, which determines whether the end of the document is moved to the scanning point or not. If the answer is yes, then the program ends, that is, the scan ends.

 As described above, in the known system for processing images of high or medium resolution when creating an optical device including a CCD, a fluorescent lamp is used as a light source. In such a fluorescent lamp, there is a difference in the amount of light between the two end parts and the middle part, a loss of light intensity due to the lens, etc. In addition, over time, the inconstancy of the amount of light becomes much greater, so that whenever a document is read, data should be generated to correct the shading distortion using a white roller or white strip.

 Therefore, in this known image processor, there is a problem in that the software for creating the data necessary to correct the shading distortion of each document is quite complicated, and the use of an expensive white roller and similar element increases the cost of the manufactured products.

Summary of the invention
An object of the present invention is to provide a device and method for scanning image data in an image processing system that stores data for correcting a shading distortion in accordance with a white document in a recording mode correcting a shading distortion and uses the stored data to correct shading distortion every time an image is scanned , by replacing the black roller with a white roller, which was used to correct the unevenness of the image data in accordance There is a change in the amount of light.

 These goals are achieved by creating a device for scanning image data in a data processing system having a scanner that contains a document feed roller, a sensing element for determining whether a document is inserted and there is printing paper, the sensitive element being brought into close contact with the roller, image processing means for converting the analog signal from the sensing element into a digital signal, a memory unit for storing data to correct shading distortion control means for creating and storing data for correcting shading distortion by supplying an output signal of an image processing means that reads a white document inserted between the roller and the sensor in recording mode with correction of shading distortion, detecting a black and white selection level based on data for correcting shading distorting and generating black and white data based on the level of black and white selection in scan mode.

 In accordance with a second aspect of the present invention, there is also provided a method of scanning image data in an image processing system including a document feed roller, a sensing element for determining whether a document is inserted and there is printing paper, the sensing element being brought into close contact with the roller, processing means image for converting the analog signal from the sensing element into a digital signal and a memory unit, which consists in determining the black selection level and storing the black selection level in the memory unit by using the data for correcting the shading distortion obtained by reading a white document inserted between the roller and the sensor in the recording mode with the correction of the shading distortion, generating black and white data based on the black and white selection level from the data, received from the image processing means in the scanning mode.

Brief Description of the Drawings
Further, the present invention and its advantages are illustrated by the description of specific variants of its embodiment with reference to the accompanying drawings, in which:
FIG. 1 depicts a known relationship between a light source and a charge coupled device (CCD) or contact image sensor (CDI);
FIG. 2 depicts a flowchart for scanning image data in a known image processing system,
FIG. 3 is a block diagram of an image processing system according to the invention;
FIG. 4 shows a flowchart of a recording mode with correction of shadowing distortion according to a method for scanning image data in an image processing system according to the invention;
FIG. 5 depicts the relationship between a black roller and a CDI and a white document according to the invention;
FIG. 6 shows a flowchart for scanning image data in an image processing system according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 3 is a block diagram of a preferred embodiment of an image processing system.

 The term "white document" means a clean registry document on which nothing is written.

 A controller 311 controls the operation of the image processing system based on a predetermined program. The controller 311 may include memory for storing the program and memory for storing data, or memory devices such as read-only memory (ROM) 313 and random access memory (RAM) 315 can be connected to the outside of the controller 311. The ROM 313 stores the program, and RAM 315 temporarily stores data generated during program execution. The power source for the RAM 315 is the battery 317, so if the main power source is turned off, the data stored in the RAM 315 is not erased.

 The control panel (PU) 312 contains a means of key input and a display. The control unit 312 generates data by pressing keys to indicate each user mode and performs the operation of the selected mode by key input and outputs the data to the controller 311. The control panel 312 performs the function of entering and displaying display data representing the operating state of the system during each mode in the controller 311. The sensing element 314 determines whether a document is inserted or not and whether there is printing paper, and outputs a status signal to the controller 311. At this time, the document is supplied m ASPD and traffic police.

 CDI 320 scans an image of a document inserted into a document reader. The automatic background control circuit (AUF) 319 makes some of the signs (letters) of a document clear by automatically perceiving a document whose background is dark. The image processor 318 processes the electrical signal supplied to it from the AUF circuit 319 and KDI 320, and converts the processed signal into data that can be processed by the controller 311. That is, the image processor 318 converts the image signal from the CDI 320 into digital data and outputs the converted digital data to the controller 311.

 The printer 316 prints the image data on the printing paper under the control of the controller 311. At this time, the printer drive is turned on and the printing operation is performed.

 In FIG. 4 is a flowchart of a recording process correcting a shading distortion based on a method for scanning image data in an image processing system.

 If it is determined in step 411 that the operation mode is a recording mode with correction of the shading distortion, the program proceeds to step 412, in which it is determined whether a white document is inserted between the CDI 320 and the black roller 512. If the answer is no, that is, if between the CDI 320 and a white document is not inserted with the black roller 512, the user permits the white document 511 to be inserted between the CDI 320 and the black roller 512 (FIG. 5). On the other hand, if the answer is positive in step 412, the controller 311 turns the KDI 320 light source in step 413, while the light reflected on the black roller 512 through the white document 511 from the light source is converted into an electrical signal by means of the KDI 320 photoelectric conversion element , and the converted electrical signal is supplied to the image processor 318. In the next step 414, the controller 311 reads data for correcting the shading distortion from the image processor 318 and stores the data in the RAM 315. Then MODULES 311 detects the level of the choice of black and white and saves the detected level in the RAM 315.

 In FIG. 5 shows the relationship of the parts between the black roller 512 and the CDI and the white document 511. As shown in FIG. 4, a recording mode with correction for shading distortion is performed when a white document 511 is inserted between the black roller and the CDI 320.

 In FIG. 6 is a flow diagram of a process for scanning image data in an image processing system according to a preferred embodiment of the invention.

 At step 611, it is determined whether the document is inserted. If it is determined at step 611 that the document is inserted, that is, when the AFSA sensor is turned on, that is, when the document is mounted on a support, the program proceeds to step 612, where the controller 311 drives the electric drive to feed the document. While DPS is on, the document is continuously fed. If the DPS is turned on, then at step 614 the light source is turned on.

 In the next step 615, the document is fed to the scanning point, scanning of the actual document begins. Then, the light from the KDI 320 light source is reflected on the black roller 512, so that when a white document 511 is inserted between the black roller 512 and the KDI 320, the KDI 320 converts the reflected light into an analog signal and outputs a converted analog signal. The converted analog signal is supplied to an image processor 318, which, in turn, converts the analog signal into a digital signal, which the controller 311 can read. After that, the program proceeds to step 616, in which the controller 311 checks the RAM 315, which stores data for correcting the shading distortion, and selects and generates black and white data for the image based on the black and white selection level by reading one line of the document. The action of the program at step 616 is performed continuously while the DPS is turned off. If the DPS is turned off at step 616, the program proceeds to step 616, which determines whether the final part of the document moves to the scanning point or not. If the answer is yes, then the program ends, that is, the scan ends.

 As described above, if scanning at the completion stage is poorly performed, the user can ensure that scanning is performed well by inserting a white document between the black roller and the contact image sensor (CDI) after setting the shadow distortion correction mode. The controller then determines the standard data for correcting shading distortion and provides duplicate data. At this time, it is possible to perform a scan without detecting data to correct shading distortion with each scan. Thanks to this, the cost of manufactured products is reduced by using a cheap black roller without using an expensive white roller.

Claims (2)

 1. Device for scanning image data in an image processing system with a scanner, comprising a roller for feeding a document, a sensor, the sensor being in close contact with the roller, a white sheet inserted between the roller and the sensor, an image processor for converting an analog signal from the sensor into a digital signal, a memory unit for storing data used to correct shading distortion, and a controller for storing data read from a white sheet in the memory unit in recordings with shading distortion correction, characterized in that a black roller is used as a roller, a contact image sensor used to read a document in scanning mode is used as a sensor, and data read from a white sheet into a memory unit in a recording mode with shading distortion correction , represent a digital signal output through the image processor, and the controller is additionally designed to determine the level of choice of white and black compared to the original ted document data output from the image processor as a digital signal, depending on the shading distortion correction of data stored in a memory unit in the scan mode, and for generating the next read document data as the data of white or black based on the choice of black and white level.  2. A method of scanning image data in an image processing system comprising a roller for feeding a document, a sensor, the sensor being in close contact with the roller, a white sheet inserted between the roller and the sensor, an image processor and a memory unit, which comprises images convert the analog signal from the sensor into a digital signal, store data read from a white sheet into a memory block in recording mode with correction of shading distortion, characterized in that a black shaft is used as a roller k, a contact image sensor used to read a document in scanning mode is used as a sensor, the data read from a white sheet in a memory unit in a recording mode with correction of shading distortion is a digital signal that is output through the image processor, the selection level is determined white and black compared to the original read data of the document, which is output from the image processor as a digital signal, depending on the correction data shading suit zheniya, stored in the memory unit in the scan mode, and generate the next readable data of the document data in the form of white or black based on the choice of black and white level.

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