WO2014134890A1

WO2014134890A1 - Image processing device and image data correction method

Info

Publication number: WO2014134890A1
Application number: PCT/CN2013/078642
Authority: WO
Inventors: 张翼飞
Original assignee: 广州广电运通金融电子股份有限公司
Priority date: 2013-03-05
Filing date: 2013-07-02
Publication date: 2014-09-12
Also published as: CN103108107A

Abstract

An image processing device and an image data correction method. The method comprises: step 1, an image sensing unit collecting image information about a piece of benchmark white paper, and outputting the greyscale data SWi thereof; step 2, the image sensing unit collecting image information about a piece of benchmark black paper, and outputting the greyscale data SBi thereof; step 3, calculating a pixel deviation compensation coefficient Ki of the image sensing unit point by point, and storing same in a storage unit, where Ki = 255 / (SWi - SBi); step 4, collecting image information about a medium to be processed, and outputting the greyscale data Xi thereof; and step 5, correcting the greyscale data of the medium to be processed according to the formula Xi' = Ki * (Xi - SBi). After the image data is calibrated, the influence of the inconsistency of each photosensitive element of the image sensing unit on the image greyscale is eliminated, thereby guaranteeing the authenticity of document medium images, and being beneficial to improve the identification effect.

Description

Image processing device and image data correction method

The present application claims priority to Chinese Patent Application No. 201310069890.7, entitled "Image Processing Apparatus and Image Data Correction Method", filed on March 5, 2013, the entire contents of which are incorporated herein by reference. In the application.

Technical field

The present invention relates to an image processing apparatus and an image data correction method for generating document medium image data by scanning an image medium such as paper, a form, or the like by an optical image sensor reading device. Background technique

In a financial institution or a corporate group, a scanner device such as an optical image sensor is used to scan a document medium such as a paper or a form to generate image data of a document medium, and the information processing device such as a CPU performs high-speed recognition and processing of the machine, thereby realizing The information processing of the document processing business such as the form is efficient.

Scanning a document medium such as paper or a form by using a scanner device such as an optical image sensor. Since the image sensor is an array of more than 1000 CMOS photosensitive elements made of Si wafers, one photosensitive element is one pixel. There is an amplifier at each pixel position, and the electrical characteristics of the 1000 photosensitive devices and the amplifying circuit have a large inconsistency with each other, thus causing the image sensor to scan the paper of uniform color brightness (ie, at the same uniform radiation input). B), the voltages outputted by the respective photosensitive devices and the amplifying circuits are different in size, so that the image brightness data formed in the image processing device is also different, causing the image to produce an uneven brightness region, which seriously affects the image quality, thereby affecting image recognition. result.

Summary of the invention The technical problem to be solved by the present invention is to provide an image processing apparatus having a function of correcting the gradation value of image data, ensuring that the brightness of the output image is uniform, thereby ensuring image quality and avoiding affecting the image recognition result.

Another technical problem to be solved by the present invention is to provide an image data correction method for ensuring that image data collected by the image processing apparatus has a uniform gradation.

The image processing device includes: an image sensing unit for collecting image information of a reference white paper, a reference black paper, and a medium to be processed; and a storage unit for storing image information collected by the image sensing unit and a control parameter and an image processing parameter of the image sensing unit; a control processing unit for automatically controlling the image sensing unit and the storage unit, and scanning a reference blank paper according to the image sensing unit Calculating a deviation compensation coefficient with the gray scale data outputted at a bright level and a dark level formed by a reference black paper, and using the offset compensation coefficient to correct the gray scale data output by the image sensing unit after acquiring image information of the medium to be processed .

Preferably, the image sensing unit comprises a row of illuminators and an array of a plurality of photosensitive elements, the control processing unit comprising an AD data converter, wherein

Any photosensitive element of the image sensing unit for receiving a reflective signal of the reference white paper and receiving a reflective signal of the reference black paper, and reflecting the reflective signal of the reference white paper and the reference black paper The reflective signal is converted into a voltage signal;

The AD data converter is configured to convert the voltage signal of the reference white paper and the voltage signal of the reference black paper into a digital signal, the digital signal of the reference white paper as the gray scale data SWi of the reference white paper, and the digital signal of the reference black paper As the gradation data SBi of the reference black paper, the pixel deviation compensation coefficient Ki = 255 / (SWi - SBi) of any one of the photosensitive elements of the image sensing unit.

Preferably, any photosensitive element of the image sensing unit is further configured to receive the medium to be processed a reflective signal, and converting the reflective signal of the medium to be processed into a voltage signal; the AD data converter is further configured to convert a voltage signal of the medium to be processed into a digital signal, and the digital signal of the medium to be processed is used as a medium to be processed Gray scale data, corrected gray scale data of the medium to be processed Xi'=Ki X (Xi-SBi preferred: the image information is color information or brightness information of the image.

Preferably, the color information is any one or any combination of a red component, a blue component, a green component, a brightness, a chroma, and a hue.

The image data correction method includes: Step 1, the image sensing unit collects image information of a reference white paper, and outputs grayscale data SWi of the reference white paper; Step 2, the image sensing unit collects a reference black paper Image information, and outputting the gray scale data SBi of the reference black paper; Step 3, calculating the pixel offset compensation coefficient Ki of the image sensing unit point by point, and storing it in a storage unit, where Ki=255/ (SWi-SBi); Step 4, acquiring image information of the medium to be processed, and outputting gray scale data of the medium to be processed; and step 5, correcting the to-be-processed according to the formula Xi' = Ki* (Xi-SBi) The gray scale data of the medium, where Xi is the corrected gray scale data. Since the image processing apparatus provided by the present invention can control the processing unit according to the image data of the reference white paper and the reference black paper, the offset compensation coefficient of each pixel can be calculated, and the deviation compensation coefficient can be used to correct the image sensor unit to collect and output each The data of the image pixels, so the image sensing unit output data is calibrated, eliminating the influence of the inconsistency of each photosensitive element of the image sensing unit on the image gradation, thereby ensuring the authenticity of the document medium image and facilitating identification. The effect is improved.

DRAWINGS

1 is a schematic structural view of a module of an image processing apparatus according to a preferred embodiment of the present invention; FIG. 2 is a block diagram of a structure of a banknote discriminating apparatus using the image processing apparatus shown in FIG. 1;

FIG. 3 is a flowchart of a method for correcting image data according to a preferred embodiment of the present invention. The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. example. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without departing from the inventive scope are the scope of the present invention.

As shown in FIG. 1 , the image processing apparatus provided in this embodiment includes an image sensing unit, a storage unit, and a control processing unit, wherein the image sensing unit includes a row of illuminators and a plurality of photosensitive elements (photosensitive) An array of components 1, a photosensitive element 2, a photosensitive element X), the image sensing unit is configured to collect image information of the medium; the storage unit is configured to store the image information and control parameters and image processing of the image sensing unit a parameter; the control processing unit is configured to automatically control the image sensing unit and the storage unit, and output gray according to the image sensing unit scanning a bright level and a dark level formed by a reference white paper and a reference black paper The degree data calculates a deviation compensation coefficient, and uses the deviation compensation coefficient to correct data of each image pixel collected and output by the image sensing unit. For example, the light level output gray scale data of any photosensitive element of the image sensing unit scanning the reference white paper is expressed as SWi, and any photosensitive element of the image sensing unit scans the dark level output gray of the reference black paper. Degree data is expressed as

SBi, the pixel deviation compensation coefficient Ki = 255 / (SWi - SBi) of the photosensitive element. The image information acquired by any photosensitive element of the image sensing unit is expressed as Xi, and the grayscale data of the image is corrected by Xi, =Ki*(Xi-SBi

In addition, the image information collected by the image sensing unit mainly refers to color information or brightness information of the image, wherein the color information is at least one of a red component, a blue component, a green component, a brightness, a chroma, and a hue.

In addition, the control processing unit further includes a data converter for converting the analog signal input by the image sensing unit into a digital gray signal.

The image processing apparatus provided in this embodiment can be applied to a banknote discriminating device, as shown in FIG. 2, The bill discriminating module comprises an image processing device provided by the present invention, a CPU and a communication module of an external main control module, wherein the image processing device is configured to collect images, magnetic and electric signals of the paper document medium, and process the collected signals. Signal, generate image, and correct image, output real document media image for identification; communication module is used to complete communication between image processing device and main control module; CPU is used to assist in processing control and communication of the image processing device Process and various other process controls.

As shown in FIG. 3, the image data correction method provided in this embodiment includes:

Step 1, the image sensing unit collects image information of a reference white paper, and outputs its gray scale data SWi;

The illuminator in the image sensing unit is caused to emit light, the photosensitive element in the image sensing unit receives the reflective signal of the reference white paper, and converts the optical signal into a voltage signal, and the AD data converter in the control processing unit converts the voltage signal A digital signal is used, and the data in the digital signal is stored as gradation data SWi of the reference white paper in the storage unit.

Step 2: The image sensing unit collects image information of a reference black paper and outputs gray scale data thereof

SBi;

The illuminator in the image sensing unit is caused to emit light, the photosensitive element in the image sensing unit receives the reflective signal of the reference black paper, and converts the optical signal into a voltage signal, and the AD data converter in the control processing unit converts the voltage signal A digital signal is used, and the data in the digital signal is stored as gradation data SBi of the reference black paper in the storage unit. Of course, step 1 and step 2 can interchange the execution order.

Step 3, calculating the pixel deviation compensation coefficient Ki of the image sensing unit point by point, and storing it in the storage unit, where Ki=255/(SWi-SBi);

Step 4, collecting image information of the medium to be processed, and acquiring gray scale data Xi;

Step 5, correct the gray scale data, that is, Xi' =Kix (Xi-SBi Thus, although the image sensing unit CIS has inconsistencies in the photosensitive elements, after calibration, the influence of the inconsistency of each photosensitive element of the image sensing unit on the image gradation is eliminated, and real image data is obtained.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, the equivalent changes of the present invention and the contents of the drawings are all included in the present invention. Within the scope of rights protection.

Claims

Rights request

1. An image processing device, characterized in that the device includes:

An image sensing unit used to collect image information of a reference white paper, a reference black paper and the medium to be processed;

A storage unit to store the image information collected by the image sensing unit and the control parameters and image processing parameters of the image sensing unit;

A control processing unit for automatically controlling the image sensing unit and the storage unit, and outputting a light level and a dark level formed by a reference white paper and a reference black paper according to the image sensing unit Calculate the deviation compensation coefficient based on the grayscale data, and use the deviation compensation coefficient to correct the grayscale data output by the image sensing unit after collecting the image information of the medium to be processed.

2. The image processing device according to claim 1, wherein the image sensing unit includes a row of light emitters and an array composed of a plurality of photosensitive elements, and the control processing unit includes an AD data converter, in,

Any photosensitive element of the image sensing unit is used to receive the reflective signal of the reference white paper and the reflective signal of the reference black paper, and combine the reflective signal of the reference white paper and the reflective signal of the reference black paper. The reflected signal is converted into a voltage signal;

The AD data converter is used to convert the voltage signal of the reference white paper and the voltage signal of the reference black paper into digital signals. The digital signal of the reference white paper is used as the grayscale data SWi of the reference white paper, and the digital signal of the reference black paper is used as the grayscale data SWi of the reference white paper. As the grayscale data SBi of the reference black paper, the pixel deviation compensation coefficient Ki of any photosensitive element of the image sensing unit is Ki=255/(SWi-SBi:).

3. The image processing device according to claim 2, characterized in that,

Any photosensitive element of the image sensing unit is also used to receive the reflective signal of the medium to be processed. signal, and convert the reflective signal of the medium to be processed into a voltage signal;

The AD data converter is also used to convert the voltage signal of the medium to be processed into a digital signal. The digital signal of the medium to be processed is used as the grayscale data of the medium to be processed. After correction, the grayscale data Xi of the medium to be processed is '=Ki X (Xi-SBi)o

4. The image processing device according to claim 1, wherein the image information is color information or brightness information of an image.

5. The image processing device according to claim 4, wherein the color information is any one or any combination of a red component, a blue component, a green component, brightness, chroma and hue.

6. An image data correction method, characterized in that the method includes:

Step 1. The image sensing unit collects the image information of a reference white paper and outputs the grayscale data SWi of the reference white paper;

Step 2. The image sensing unit collects the image information of a reference black paper and outputs the grayscale data SBi of the reference black paper;

Step 3: Calculate the pixel deviation compensation coefficient Ki of the image sensing unit point by point, and store it in a storage unit, where Ki=255/(SWi-SBi);

Step 4, collect the image information of the medium to be processed, and output the grayscale data Xi of the medium to be processed; and

Step 5: Correct the grayscale data Xi of the medium to be processed according to the formula Xi, =Ki X (Xi-SBi), where Xi is the corrected grayscale data.