WO2019019383A1

WO2019019383A1 - Image correction method and apparatus, storage medium and computer device

Info

Publication number: WO2019019383A1
Application number: PCT/CN2017/104659
Authority: WO
Inventors: 马向东; 高雪; 丁杰; 李斌; 陈杰; 邵正铂; 张捷
Original assignee: 平安科技（深圳）有限公司
Priority date: 2017-07-25
Filing date: 2017-09-29
Publication date: 2019-01-31
Also published as: CN107680046A

Abstract

Disclosed is an image correction method, comprising: acquiring a document image to be corrected; carrying out binarization processing on the document image to obtain a binary image; according to the distribution of pixel values in the binary image, determining a tilt angle of a frame in the binary image; according to the size of a connected domain in the binary image, determining the location of a title in the binary image; according to the tilt angle of the frame and the location of the title, determining a tilt angle of the document image; and according to the tilt angle of the document image, correcting the direction of the document image to obtain a document image having been subjected to direction correction.

Description

Image correction method, device, storage medium and computer equipment

Cross-reference to related applications

The present application claims to be filed on July 25, 2017, the Chinese Patent Office, the number of which is the number of the Japanese Patent Application No. PCT Application No. In this application.

Technical field

The present application relates to the field of computer technology, and in particular, to an image correction method, apparatus, storage medium, and computer device.

Background technique

Nowadays, insurance as a product has been accepted and used by more and more users. When purchasing insurance, users often need to manually fill in the relevant information on the paper insurance certificate, and the business personnel will save the document image obtained by scanning or photographing the insurance document after filling in the relevant information on paper.

However, the document image obtained by scanning or photographing will inevitably have the problem of being reversed or tilted, and the document image needs to be corrected. At present, the correction of the document image relies on the manual correction by the business personnel, resulting in inefficiency in correcting the document image.

Summary of the invention

According to various embodiments of the present application, an image correction method, apparatus, storage medium, and computer apparatus are provided.

An image correction method includes:

Obtaining the document image to be corrected;

Performing binarization processing on the document image to obtain a binary image;

Determining a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image;

Determining a position of a title in the binary image according to a size of a connected domain in the binary image;

Determining a tilt angle of the document image according to a tilt angle of the frame and a position of the title; and

The direction of the document image is corrected according to the tilt angle of the document image, and the document image corrected by the direction is obtained.

An image correcting device comprising:

Obtaining a module for acquiring a document image to be corrected;

a processing module, configured to perform binarization processing on the document image to obtain a binary image;

a determining module, configured to determine a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image; determining a position of a header in the binary image according to a size of a connected domain in the binary image; Determining a tilt angle of the document image according to a tilt angle of the frame and a position of the title; and

The correction module is configured to perform direction correction on the document image according to the tilt angle of the document image, and obtain a document image that has undergone direction correction.

One or more computer readable non-volatile storage media storing computer readable instructions, when executed by one or more processors, cause the one or more processors to perform the steps of:

Obtaining the document image to be corrected;

A computer device comprising a memory and a processor, the memory storing computer readable instructions, the computer readable instructions being executed by the processor, causing the processor to execute Next steps:

Obtaining the document image to be corrected;

Details of one or more embodiments of the present application are set forth in the accompanying drawings and description below. Other features, objects, and advantages of the invention will be apparent from the description and appended claims.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings to be used in the embodiments will be briefly described below. Obviously, the drawings in the following description are only some embodiments of the present application, Those skilled in the art can also obtain other drawings based on these drawings without any creative work.

1 is a diagram showing the internal structure of a computer device in an embodiment;

2 is a schematic flow chart of an image correction method in an embodiment;

3 is a schematic diagram of a document image before and after binarization in one embodiment;

4 is a schematic diagram of a tilt angle of a frame in a document image in an embodiment;

FIG. 5 is a schematic flow chart of an image correction method in another embodiment; FIG.

Fig. 6 is a block diagram showing the structure of an image correcting device in an embodiment.

Detailed ways

In order to make the objects, technical solutions, and advantages of the present application more comprehensible, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific implementation described herein The examples are only used to explain the present application and are not intended to limit the application.

FIG. 1 is a schematic diagram showing the internal structure of a computer device in an embodiment. As shown in FIG. 1, the computer device includes a processor and a memory connected by a system bus. Wherein, the memory comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device can store an operating system and computer readable instructions that, when executed, cause the processor to perform an image correction method. The processor of the computer device is used to provide computing and control capabilities to support the operation of the entire computer device. The internal memory can also store computer readable instructions for implementing an image correction method provided by the following embodiments when the computer readable instructions are executed by a processor. A person skilled in the art can understand that the structure shown in FIG. 1 is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the terminal to which the solution of the present application is applied. The specific terminal may include a ratio. More or fewer components are shown in the figures, or some components are combined, or have different component arrangements.

As shown in Figure 2, in one embodiment, an image correction method is provided. This embodiment is mainly illustrated by the method applied to the computer device in FIG. 1 described above. Referring to FIG. 2, the image correction method specifically includes the following steps:

S202. Acquire a document image to be corrected.

The document image is an image containing a document, and may be a document photo or a document scan. The document image to be corrected is a document image that requires direction correction. The computer device can obtain a document image by photographing a physical document through a camera of the computer device, or obtain a document image by scanning a physical document by a scanner, or receiving a document image transmitted by another computer device.

S204, performing binarization processing on the document image to obtain a binary image.

Among them, binarization is to set the pixel points on the image to two pixel values. For example, set the gray value of the pixel on the image to 0 or 255.

Specifically, the computer device may use a fixed threshold binarization algorithm or an adaptive threshold binarization algorithm to set pixel values above and below the threshold in the document image to one of two preset pixel values. The two pixel values are the first pixel value and the second pixel value, respectively.

In one embodiment, the computer device can read from the document image by calling MATLAB. The RGB value of each pixel in the document image is calculated, and the gradation value of each pixel is calculated according to the RGB value of each pixel. The gray value of each pixel in the document image is compared with a preset threshold, the gray value greater than the preset threshold is set to "1", and the gray value less than or equal to the preset threshold is set to "0" , binarize each pixel of the document image to obtain a binary image.

S206. Determine a tilt angle of the border in the binary image according to the distribution of pixel values in the binary image.

Among them, the border is a peripheral frame. The content enclosed by the border is the content of the document. The tilt angle is the angle from the standard direction. The standard direction can be horizontal or vertical. The tilt angle may specifically be an angle deviating from the horizontal direction, the direction is a clockwise direction, or may be an angle deviating from the vertical direction, and the direction is a counterclockwise direction.

Specifically, the computer device can traverse the pixel values of the respective pixel points row by line, recognize the detected consecutive pixel values having the same pixel value as a straight line, and determine the straight line constituting the frame from the recognized straight lines. The computer device can recalculate the angle of the line from the direction of the label, thereby obtaining the tilt angle of the frame. The computer device may specifically adopt an algorithm such as a principal component analysis (PCA) algorithm or a least squares regression algorithm to obtain a tilt angle of a straight line constituting the frame.

Figure 3 is a diagram showing the tilt angle of the border in the document image in one embodiment. Referring to Figure 3, the schematic shows a bezel 310 and a tilt angle 320. Wherein, the inclination angle 320 may be an angle 321 deviating from the horizontal direction, the direction is a clockwise direction; or may be an angle 322 deviating from the vertical direction, and the direction is a counterclockwise direction.

S208. Determine a position of the title in the binary image according to the size of the connected domain in the binary image.

Under normal circumstances, the character of the title in the document image is determined to be the largest. In this embodiment, the computer device can obtain the connected domain included in the document image, determine the size of each connected domain, and select the location of the largest connected domain as the location of the title.

S210: Determine a tilt angle of the document image according to the tilt angle of the border and the position of the title.

Specifically, the computer device can determine the direction of the text sequence in the title, and determine the tilt angle of the document image based on the direction of the text sequence in the title, the position of the title in the document image, and the tilt angle of the frame.

When the standard direction is horizontal and the position of the title is at the top of the binary image, if in the title The angle between the direction of the text sequence and the horizontal direction to the right is an acute angle, and the inclination angle of the document image is the complementary angle of the inclination angle of the frame, and the direction of the inclination angle is counterclockwise; if the direction and the horizontal direction of the text sequence in the title The angle in the right direction is an obtuse angle, and the inclination angle of the document image is the complementary angle of the inclination angle of the frame, and the direction of the inclination angle is counterclockwise.

When the standard direction is the horizontal direction and the position of the title is the right side of the binary image, if the angle between the direction of the text sequence in the title and the horizontal right direction is an acute angle, the inclination angle of the document image is the inclination angle of the frame. Add a right angle, and the direction of the tilt angle is clockwise; if the angle between the direction of the text sequence in the title and the horizontal right direction is an obtuse angle, the tilt angle of the document image is the complement angle of the tilt angle of the frame, and the tilt angle The direction is counterclockwise.

When the standard direction is the horizontal direction and the position of the title is the bottom of the binary image, if the angle between the direction of the text sequence in the title and the horizontal right direction is an acute angle, the inclination angle of the document image is the inclination angle of the frame. And the oblique angle direction is clockwise; if the angle between the direction of the text sequence in the title and the horizontal right direction is an obtuse angle, the inclination angle of the document image is the complementary angle of the inclination angle of the frame, and the inclination angle direction is clockwise direction.

When the standard direction is the horizontal direction and the position of the title is the left side of the binary image, if the angle between the direction of the text sequence in the title and the horizontal right direction is an acute angle, the inclination angle of the document image is the inclination angle of the frame. And the oblique angle direction is clockwise; if the angle between the direction of the text sequence in the title and the horizontal right direction is an obtuse angle, the tilt angle of the document image is the complementary angle of the tilt angle of the frame, and the tilt angle direction is inverse Hour direction.

When the standard direction is the vertical direction and the position of the title is the top of the binary image, if the angle between the direction of the text sequence in the title and the vertical upward direction is an acute angle, the inclination angle of the document image is the inclination angle of the frame plus Right angle, and the direction of the tilt angle is counterclockwise; if the angle between the direction of the text sequence in the title and the upward direction of the water quality is an obtuse angle, the tilt angle of the document image is the tilt angle of the frame, and the tilt angle direction is counterclockwise.

When the standard direction is the vertical direction and the position of the title is the right side of the binary image, if the angle between the direction of the text sequence in the title and the vertical upward direction is an acute angle, the inclination angle of the document image is the inclination angle of the frame plus Upright angle, and the direction of the tilt angle is counterclockwise; if the direction of the text sequence in the title The angle with the vertical upward direction is an obtuse angle, and the inclination angle of the document image is the inclination angle of the frame plus a right angle, and the inclination angle direction is a counterclockwise direction.

When the standard direction is the vertical direction and the position of the title is the bottom of the binary image, if the angle between the direction of the text sequence in the title and the vertical upward direction is an acute angle, the inclination angle of the document image is the complement of the inclination angle of the frame. Angle, and the direction of the oblique angle is clockwise; if the angle between the direction of the text sequence in the title and the vertical upward direction is an obtuse angle, the inclination angle of the document image is the complementary angle of the inclination angle of the frame, and the direction of the inclination angle is smooth Hour direction.

When the standard direction is the vertical direction and the position of the title is the left side of the binary image, if the angle between the direction of the text sequence in the title and the vertical upward direction is an acute angle, the inclination angle of the document image is the inclination angle of the frame. The complementary angle, and the direction of the oblique angle is clockwise; if the angle between the direction of the text sequence in the title and the vertical upward direction is an obtuse angle, the inclination angle of the document image is the inclination angle of the frame, and the direction of the inclination angle is counterclockwise .

Figure 4 is a diagram showing the tilt angle of a document image in one embodiment. Referring to Figure 4, the schematic shows a bezel 410, a tilt angle 420, and a title 430. The tilt angle 420 may be an angle 421 offset from the horizontal direction, the direction is a clockwise direction, or may be an angle 422 deviating from the vertical direction, the direction being a clockwise direction.

S212, correcting the direction of the document image according to the tilt angle of the document image, and obtaining the document image corrected by the direction.

Specifically, the computer device can rotate the document image by an angle equal to the tilt angle in a direction of decreasing the tilt angle according to the tilt angle of the document image, thereby realizing the direction correction of the document image.

After obtaining the document image to be corrected, the image correction method automatically binarizes the document image to obtain a binary image, and can determine the tilt angle of the document image frame and the document image according to the binary image. The position of the title, so as to determine the tilt angle of the document image according to the tilt angle of the document image frame and the position of the document image title, the direction of the document image can be corrected according to the tilt angle of the document image, and the direction correction is obtained. The document image avoids the workload introduced by manual correction and greatly improves the image correction efficiency.

In an embodiment, step S206 includes: extracting according to a distribution of pixel values in the binary image. a straight line included in the binary image; calculating a coordinate position of the intersection formed between the extracted straight lines; determining a straight line constituting the frame in the binary image according to the coordinate position of the intersection; determining the inclination angle of the frame according to the inclination angle of the straight line constituting the frame.

Specifically, the computer device can traverse the pixel values of the respective pixel points row by row or column by column, and recognize the detected consecutive pixel values having the same pixel value as a straight line. The computer device can further determine the intersection formed between the straight lines, and determine the pixel position of the pixel at the intersection position as the coordinate position of the intersection. The computer device can further select the maximum value and the minimum value of the abscissa and the maximum value and the minimum value of the ordinate for the coordinate positions of all the intersection points, thereby determining the straight line constituting the frame in the binary image according to the determined maximum value and the minimum value. The inclination angle of the bezel is determined according to the inclination angle of the straight line constituting the bezel.

In one embodiment, in a Cartesian coordinate system, the Cartesian coordinate equation of the line is y=kx+b. In the polar coordinate space, the polar coordinate equation of the straight line is ρ=x·cos(θ)+y·sin(θ). Where ρ is the vertical distance from the origin to the straight line, and θ is the angle between the perpendicular and the X axis, θ=π*k/180°. For a straight line LA passing through point A (x1, y1) and a straight line LB passing through point B (x2, y2), if round(ρ _A ) = round(ρ _B ) and θ _A = θ _B , then point A and point B On the same line. A point in the Cartesian coordinate space corresponds to a line in the polar coordinate space, and a point in the polar coordinate space corresponds to a line in the Cartesian coordinate space.

Further, "1" in the binary image represents the background, and "0" represents the line. The computer device obtains a sinusoidal curve in the parameter plane by polar coordinate transformation by taking the pixel position (Xi, Yi) of the pixel point where each pixel value in the binary image is "0". The parameters k and b of the intersection corresponding to the straight line in the binary image plane can be calculated according to the coordinate position (ρ, θ) of the intersection position of each sinusoid.

The computer device can further determine the intersection formed between the straight lines, and determine the pixel position of the pixel at the intersection position as the coordinate position of the intersection. The computer device can further select the maximum value and the minimum value of the abscissa and the maximum value and the minimum value of the ordinate for the coordinate positions of all the intersection points, thereby determining the straight line constituting the frame in the binary image according to the determined maximum value and the minimum value. The inclination angle of the bezel is determined according to the inclination angle of the straight line constituting the bezel.

In the above embodiment, after the straight line is extracted from the binary image, the straight line constituting the frame in the binary image is determined according to the intersection of the straight lines, and the inclination of the frame is determined according to the inclination angle of the straight line constituting the frame. The angle ensures the accuracy of the determined tilt angle of the border.

In an embodiment, step S208 includes: extracting a connected domain in the binary image; acquiring a short side length of each connected domain; determining a position of the connected domain having the longest shortest side length as a position of the title in the binary image .

Specifically, the computer device may perform the connected domain analysis on the binarized document image to extract the connected domain, and may also merge the adjacent connected domains. The computer device can use the Run Length Smooth Algorithm (RLSA) algorithm to analyze and merge the connected domains. The algorithm can connect the pixels of adjacent connected domains to form a monolithic region, because the same text sequence is internal. The distance between the connected domains is relatively close, so the connected domains in the same text sequence can form a complete connected domain.

Further, the computer device can determine the outer contour of the connected domain as the location of the connected domain. When the outer contour of the connected domain is represented by a rectangle, the position of the connected domain can be represented by a vertex of the rectangle and a rectangle width and a rectangle height. The short side of the connected domain is roughly the width or height of the character, and the computer device can determine the short side length of each connected domain, and determine the position of the connected domain having the longest short side length as the position of the title in the binary image.

In the present embodiment, the position of the title in the binary image is automatically determined based on the length of the short side of the connected domain, and the accuracy of the determined position of the title is ensured.

In an embodiment, after step S204, the image correction method further comprises: removing noise in the binary image according to the distribution of pixel values in the binary image.

Among them, noise is a dead point generated during binarization processing. The process of removing noise is to change the process of some isolated first pixel value "1" representing the background point to the second pixel value "0" representing the former attraction. In the present embodiment, four consecutive and below noises are removed.

In this embodiment, after the binary image is binarized to obtain a binary image, the denoising process is performed, thereby avoiding the influence of the noise on the determination of the subsequent frame tilt angle, and ensuring effective subsequent data processing.

In an embodiment, after the step S212, the image correction method further comprises: performing redundant cutting on the direction-corrected document image according to the position of the border in the binary image, and obtaining a redundant cut. Cut the documentary image.

Specifically, the computer device can determine the area outside the border as a redundant part according to the border in the binary image, perform cutting, and retain the area enclosed by the border, thereby eliminating the problem that the edge of the document image is too much, and obtaining the correcting direction and Crop redundant document images.

As shown in FIG. 5, in a specific embodiment, the image correction method specifically includes the following steps:

S502. Acquire a document image to be corrected.

S504, performing binarization processing on the document image to obtain a binary image.

S506. Remove noise in the binary image according to the distribution of pixel values in the binary image.

S508, extracting a line included in the binary image according to the distribution of the pixel values in the binary image; calculating a coordinate position of the intersection formed between the extracted lines; determining a line forming the frame in the binary image according to the coordinate position of the intersection; The inclination angle of the line constituting the frame determines the inclination angle of the frame.

S510. Extract a connected domain in the binary image; obtain a short side length of each connected domain; and determine a position of the connected domain having the longest shortest side length as a position of the title in the binary image.

S512, determining the tilt angle of the document image according to the tilt angle of the border and the position of the title.

S514, correcting the direction of the document image according to the tilt angle of the document image, and obtaining the document image corrected by the direction.

S516: Perform redundant cutting on the corrected direction image according to the position of the border in the binary image to obtain a redundantly cut document image.

In this embodiment, after acquiring the document image to be corrected, the document image is automatically binarized to obtain a binary image, and the tilt angle of the document image frame and the document can be determined according to the binary image. The position of the image title, so as to determine the tilt angle of the document image according to the tilt angle of the document image frame and the position of the document image title, the direction of the document image can be corrected according to the tilt angle of the document image, and the direction correction is obtained. The documentary image avoids the workload introduced by manual correction and greatly improves the image correction efficiency.

It should be understood that although the respective steps in the flowcharts of the above embodiments are sequentially displayed in accordance with the indication of the arrows, these steps are not necessarily performed in the order indicated by the arrows. Except as expressly stated in this document, there are no strict order limits for the execution of these steps. Execute in other order. Moreover, at least some of the steps in the above embodiments may include a plurality of sub-steps or stages, which are not necessarily performed at the same time, but may be executed at different times, and these sub-steps or stages The order of execution is not necessarily performed sequentially, but may be performed alternately or alternately with at least a portion of other steps or sub-steps or stages of other steps.

As shown in FIG. 6, an image correction device 600 is provided. The image correction device 600 includes an acquisition module 601, a processing module 602, a determination module 603, and a correction module 604.

The obtaining module 601 is configured to obtain a document image to be corrected.

The processing module 602 is configured to perform binarization processing on the document image to obtain a binary image.

a determining module 603, configured to determine a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image; determine a position of the header in the binary image according to a size of the connected domain in the binary image; according to a tilt angle and a title of the border The position of the image determines the tilt angle of the document.

The correction module 604 is configured to perform direction correction on the document image according to the tilt angle of the document image, and obtain a document image corrected by the direction.

After obtaining the document image to be corrected, the image correcting device 600 automatically binarizes the document image to obtain a binary image, and can determine the tilt angle of the document image frame and the document according to the binary image. The position of the image title, so as to determine the tilt angle of the document image according to the tilt angle of the document image frame and the position of the document image title, the direction of the document image can be corrected according to the tilt angle of the document image, and the direction correction is obtained. The documentary image avoids the workload introduced by manual correction and greatly improves the image correction efficiency.

In an embodiment, the determining module 603 is further configured to: extract a line included in the binary image according to the distribution of the pixel values in the binary image; calculate a coordinate position of the intersection formed between the extracted straight lines; determine according to the coordinate position of the intersection point A line constituting a frame in the binary image; the inclination angle of the frame is determined according to the inclination angle of the line constituting the frame.

In this embodiment, after the straight line is extracted from the binary image, the straight line constituting the frame in the binary image is determined according to the intersection point of the straight line, and the tilt angle of the frame is determined according to the inclination angle of the straight line constituting the frame, thereby ensuring the determined border. The accuracy of the tilt angle.

In an embodiment, the determining module 603 is further configured to extract the connected domain in the binary image; obtain the short side length of each connected domain; and determine the position of the connected domain with the longest shortest edge length as the title in the binary image s position.

In one embodiment, the processing module 602 is further configured to remove noise in the binary image according to the distribution of pixel values in the binary image.

In one embodiment, the correction module 604 is further configured to perform redundant cutting on the direction-corrected document image according to the position of the border in the binary image to obtain a redundantly cut document image.

In this embodiment, the problem of excessive edge of the document image is eliminated.

In one embodiment, the image correcting device in each of the above embodiments may be implemented in the form of a computer program, and the computer readable instructions corresponding to the computer program may be run on a computer device as shown in FIG.

Each of the above-described image correcting devices may be implemented in whole or in part by software, hardware, and combinations thereof. The network interface may be an Ethernet card or a wireless network card. The above modules may be embedded in the hardware of the terminal or may be stored in the memory of the terminal in a software form, so that the processor calls the execution of the operations corresponding to the above modules. The processor can be a central processing unit (CPU), a microprocessor, a microcontroller, or the like.

In one embodiment, one or more computer readable non-volatile storage media having computer readable instructions stored by one or more processors are provided for causing one or more processes Performing the following steps: obtaining a document image to be corrected; binarizing the document image to obtain a binary image; determining a tilt angle of the border in the binary image according to the distribution of pixel values in the binary image; according to the binary image The size of the connected domain determines the position of the title in the binary image; the tilt angle of the document image is determined according to the tilt angle of the border and the position of the title; The oblique angle corrects the direction of the document image, and obtains the document image corrected by the direction.

In one embodiment, determining the tilt angle of the border in the binary image according to the distribution of the pixel values in the binary image comprises: extracting a line included in the binary image according to the distribution of pixel values in the binary image; calculating the extracted straight line The coordinate position of the intersection formed between the two; the straight line constituting the frame in the binary image is determined according to the coordinate position of the intersection; and the inclination angle of the frame is determined according to the inclination angle of the straight line constituting the frame.

In an embodiment, determining the position of the title in the binary image according to the size of the connected domain in the binary image comprises: extracting a connected domain in the binary image; acquiring a short side length of each connected domain; The position of the long connected domain is determined as the position of the title in the binary image.

In one embodiment, the computer readable instructions cause one or more processors to perform binarization processing on the document image to obtain a binary image, and further perform the step of removing the binary value according to the distribution of pixel values in the binary image Noise in the image.

In one embodiment, the computer readable instructions cause one or more processors to perform direction correction on the document image according to the tilt angle of the document image, and after obtaining the direction corrected document image, performing the following steps: The position of the border in the value image is redundantly cropped by the direction-corrected document image to obtain a redundantly cut document image.

After obtaining the document image to be corrected, the storage medium automatically binarizes the document image to obtain a binary image, and the tilt angle of the document image frame and the document image title can be determined according to the binary image. The position is determined according to the inclination angle of the document image frame and the position of the document image title, and the direction of the document image can be corrected according to the inclination angle of the document image, and the direction correction is obtained. The image is proofed, thus avoiding the workload introduced by manual correction and greatly improving the image correction efficiency.

In one embodiment, a computer apparatus is provided, comprising a memory and a processor, the memory storing computer readable instructions, the computer readable instructions being executed by the processor, causing the processor to perform the step of: obtaining a single to be corrected The image is obtained by binarizing the document image to obtain a binary image; determining the tilt angle of the border in the binary image according to the distribution of the pixel values in the binary image; determining the binary image according to the size of the connected domain in the binary image The position of the title; the tilt angle of the document image is determined according to the tilt angle of the border and the position of the title; the image of the document is entered according to the tilt angle of the document image Correction of the direction of the line, obtaining a document image that has been corrected by direction.

In one embodiment, the computer readable instructions cause the processor to perform binarization processing on the document image to obtain a binary image, and further perform the following steps: removing noise in the binary image according to the distribution of pixel values in the binary image .

In one embodiment, the computer readable instructions cause the processor to perform direction correction on the document image according to the tilt angle of the document image, and after obtaining the direction corrected document image, performing the following steps: according to the border in the binary image The location of the corrected image of the corrected image is redundantly cropped to obtain a redundantly cut document image.

After obtaining the document image to be corrected, the computer device automatically binarizes the document image to obtain a binary image, and can determine the tilt angle of the document image frame and the document image title according to the binary image. The position is determined according to the inclination angle of the document image frame and the position of the document image title, and the direction of the document image can be corrected according to the inclination angle of the document image, and the direction correction is obtained. The image is proofed, thus avoiding the workload introduced by manual correction and greatly improving the image correction efficiency.

One of ordinary skill in the art can understand that all or part of the process of implementing the above embodiments can be completed by a computer program to instruct related hardware, and the program can be stored in a non-volatile computer readable storage medium. Wherein, the program, when executed, may include the flow of an embodiment of the methods as described above. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or the like.

The technical features of the above embodiments may be combined in any combination, so that the description is concise, All possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope of the present specification.

The above-mentioned embodiments are merely illustrative of several embodiments of the present application, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the claims. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the present application. Therefore, the scope of the invention should be determined by the appended claims.

Claims

An image correction method includes:

Obtaining the document image to be corrected;

Performing binarization processing on the document image to obtain a binary image;

Determining a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image;

Determining a position of a title in the binary image according to a size of a connected domain in the binary image;

Determining a tilt angle of the document image according to a tilt angle of the frame and a position of the title; and

The direction of the document image is corrected according to the tilt angle of the document image, and the document image corrected by the direction is obtained.
The method according to claim 1, wherein the determining a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image comprises:

Extracting a line included in the binary image according to a distribution of pixel values in the binary image;

Calculating a coordinate position of an intersection formed between the extracted straight lines;

Determining a line constituting a frame in the binary image according to the coordinate position of the intersection; and

The inclination angle of the frame is determined according to the inclination angle of the straight line constituting the frame.
The method according to claim 1, wherein the determining the position of the title in the binary image according to the size of the connected domain in the binary image comprises:

Extracting a connected domain in the binary image;

Obtaining a short side length of each of the connected domains; and

The position of the connected domain having the longest length of the short side is determined as the position of the title in the binary image.
The method according to claim 1, wherein the binarizing the image of the document to obtain a binary image further comprises:

The noise in the binary image is removed according to a distribution of pixel values in the binary image.
The method according to claim 1, wherein the correcting the direction of the document image according to the tilt angle of the document image, and obtaining the document image after the direction correction comprises:

According to the position of the border in the binary image, the direction-corrected document image is redundantly cropped to obtain a redundantly cut document image.
An image correcting device comprising:

Obtaining a module for acquiring a document image to be corrected;

a processing module, configured to perform binarization processing on the document image to obtain a binary image;

a determining module, configured to determine a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image; determining a position of a header in the binary image according to a size of a connected domain in the binary image; Determining a tilt angle of the document image according to a tilt angle of the frame and a position of the title; and

The correction module is configured to perform direction correction on the document image according to the tilt angle of the document image, and obtain a document image that has undergone direction correction.
The apparatus according to claim 6, wherein the determining module is further configured to extract a line included in the binary image according to a distribution of pixel values in the binary image; and calculate the extracted straight line a coordinate position of the intersection formed therebetween; determining a straight line constituting the frame in the binary image according to the coordinate position of the intersection; and determining a tilt angle of the frame according to the inclination angle of the straight line constituting the frame.
The apparatus according to claim 6, wherein the determining module is further configured to extract a connected domain in the binary image; acquire a short side length of each connected domain; and have a longest corresponding short side length The position of the connected domain is determined as the position of the title in the binary image.
The apparatus according to claim 6, wherein the processing module is further configured to remove noise in the binary image according to a distribution of pixel values in the binary image.
The device according to claim 6, wherein the correction module is further configured to perform redundant cutting on the direction-corrected document image according to the position of the border in the binary image, and obtain redundantly cropped Document image.
One or more computer readable non-volatile storage media storing computer readable instructions, when executed by one or more processors, cause the one or more processors to perform the steps of:

Obtaining the document image to be corrected;

Performing binarization processing on the document image to obtain a binary image;

Determining a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image;

Determining a position of a title in the binary image according to a size of a connected domain in the binary image;

Determining a tilt angle of the document image according to a tilt angle of the frame and a position of the title; and

The direction of the document image is corrected according to the tilt angle of the document image, and the document image corrected by the direction is obtained.
The storage medium according to claim 11, wherein the determining a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image comprises:

Extracting a line included in the binary image according to a distribution of pixel values in the binary image;

Calculating a coordinate position of an intersection formed between the extracted straight lines;

Determining a line constituting a frame in the binary image according to the coordinate position of the intersection; and

The inclination angle of the frame is determined according to the inclination angle of the straight line constituting the frame.
The storage medium according to claim 11, wherein the determining the position of the title in the binary image according to the size of the connected domain in the binary image comprises:

Extracting a connected domain in the binary image;

Obtaining a short side length of each of the connected domains; and

The position of the connected domain having the longest length of the short side is determined as the position of the title in the binary image.
The storage medium according to claim 11, wherein the computer readable instructions cause the one or more processors to perform binarization processing on the document image to obtain a binary image, and then perform the following steps:

The noise in the binary image is removed according to a distribution of pixel values in the binary image.
The storage medium according to claim 11, wherein the computer readable instructions cause one or more processors to perform direction correction on the document image according to a tilt angle of the document image to obtain a passing direction Perform the following steps after correcting the document image:

Redundancy of the direction-corrected document image according to the position of the border in the binary image Crop to obtain a redundantly cropped document image.
A computer device comprising a memory and a processor, the memory storing computer readable instructions, the computer readable instructions being executed by the processor such that the processor performs the following steps:

Obtaining the document image to be corrected;

Performing binarization processing on the document image to obtain a binary image;

Determining a tilt angle of a border in the binary image according to a distribution of pixel values in the binary image;

Determining a position of a title in the binary image according to a size of a connected domain in the binary image;

Determining a tilt angle of the document image according to a tilt angle of the frame and a position of the title; and

The direction of the document image is corrected according to the tilt angle of the document image, and the document image corrected by the direction is obtained.
The computer device according to claim 16, wherein the determining the tilt angle of the border in the binary image according to the distribution of the pixel values in the binary image comprises:

Extracting a line included in the binary image according to a distribution of pixel values in the binary image;

Calculating a coordinate position of an intersection formed between the extracted straight lines;

Determining a line constituting a frame in the binary image according to the coordinate position of the intersection; and

The inclination angle of the frame is determined according to the inclination angle of the straight line constituting the frame.
The computer device according to claim 16, wherein the determining the location of the title in the binary image according to the size of the connected domain in the binary image comprises:

Extracting a connected domain in the binary image;

Obtaining a short side length of each of the connected domains; and

The position of the connected domain having the longest length of the short side is determined as the position of the title in the binary image.
The computer apparatus according to claim 16, wherein the computer readable instructions cause the processor to perform a binarization process on the document image to obtain a binary image, and then perform the following steps:

The noise in the binary image is removed according to a distribution of pixel values in the binary image.
The computer apparatus according to claim 16, wherein the computer readable instructions cause the processor to perform direction correction on the document image according to a tilt angle of the document image to obtain a direction corrected document Perform the following steps after the image:

According to the position of the border in the binary image, the direction-corrected document image is redundantly cropped to obtain a redundantly cut document image.