CN-112040151-B - Image noise processing method and device, image sensor and storage medium

CN112040151BCN 112040151 BCN112040151 BCN 112040151BCN-112040151-B

Abstract

The invention provides an image noise processing method, an image noise processing device, an image sensor and a storage medium, wherein the method comprises the steps of obtaining a reference column where a reference pixel with preset characteristics in a pixel array is located; and eliminating the fixed pattern noise of the effective pixels in the target column indicated by the position of the reference column in the pixel array. The invention can only process the noise elimination for the column pixels with fixed pattern noise, avoid influencing the column pixels without fixed pattern noise, improve the noise elimination effect and ensure the image presentation effect.

Inventors

XIE YONG
GUO XIANQING
LIU KUN

Assignees

比亚迪股份有限公司

Dates

Publication Date: 20260505
Application Date: 20190604

Claims (10)

1. An image noise processing method, characterized by comprising the steps of: acquiring a reference column in which a reference pixel with preset characteristics is located in a pixel array, wherein the reference pixel with the preset characteristics is a pixel incapable of sensing illumination; For a first reference pixel in each of the reference columns, determining a first noise signal for the first reference pixel and determining a second noise signal for a second reference pixel in a preceding column of the reference columns and a third noise signal for a third reference pixel in a following column of the reference columns; determining whether fixed pattern noise is present in the reference column based on the first noise signal, the second noise signal, and the third noise signal; The determining whether the fixed pattern noise exists for the reference column based on the first noise signal, the second noise signal, and the third noise signal includes: the first noise signal and the second noise signal are subjected to difference to obtain a first difference value, the number of the first difference values is a plurality of, and the number of the first difference values is the number of rows with first reference pixels in the reference column; The first noise signal and the third noise signal are subjected to difference to obtain second difference values, the number of the second difference values is a plurality of, and the number of the second difference values is the number of rows with first reference pixels in the reference column; Calculating a first proportional value of positive numbers and reference pixel line numbers of the signs of the first difference values, and a second proportional value of positive numbers and reference pixel line numbers of the signs of the second difference values; when the first proportion value and the second proportion value are both larger than a preset threshold value, determining that the fixed pattern noise exists in the reference column; determining a location of the reference column upon determining that the reference column is in the presence of the fixed pattern noise; And eliminating fixed pattern noise of effective pixels in a target column indicated by the position of the reference column in the pixel array.
2. The image noise processing method according to claim 1, wherein the performing the elimination processing on the fixed pattern noise of the effective pixels in the target column indicated by the position of the reference column in the pixel array includes: Determining a parameter value of an effective pixel in the target column and a parameter value of the reference pixel; and carrying out difference on the parameter value of the effective pixel and the parameter value of the reference pixel, and updating the parameter value of the corresponding effective pixel according to the result obtained by the difference.
3. The image noise processing method according to claim 1, further comprising: And determining the preset threshold according to the reference pixel line number.
4. The image noise processing method according to claim 3, further comprising: an average of the first difference and the second difference is determined and used as a parameter value of the reference pixel.
5. An image noise processing apparatus, characterized in that the apparatus comprises: the acquisition module is used for acquiring a reference column where a reference pixel with a preset characteristic is located in the pixel array, wherein the reference pixel with the preset characteristic is a pixel incapable of sensing illumination; a first determining module configured to determine, for a first reference pixel in each of the reference columns, a first noise signal of the first reference pixel, and determine a second noise signal of a second reference pixel in a preceding column of the reference columns, and a third noise signal of a third reference pixel in a following column of the reference columns; determining whether fixed pattern noise is present in the reference column based on the first noise signal, the second noise signal, and the third noise signal; determining a location of the reference column upon determining that the reference column is in the presence of the fixed pattern noise; The first determining module is further specifically configured to: the first noise signal and the second noise signal are subjected to difference to obtain a first difference value, the number of the first difference values is a plurality of, and the number of the first difference values is the number of rows with first reference pixels in the reference column; The first noise signal and the third noise signal are subjected to difference to obtain second difference values, the number of the second difference values is a plurality of, and the number of the second difference values is the number of rows with first reference pixels in the reference column; Calculating a first proportional value of positive numbers and reference pixel line numbers of the signs of the first difference values, and a second proportional value of positive numbers and reference pixel line numbers of the signs of the second difference values; when the first proportion value and the second proportion value are both larger than a preset threshold value, determining that the fixed pattern noise exists in the reference column; And the processing module is used for eliminating the fixed pattern noise of the effective pixels in the target column indicated by the position of the reference column in the pixel array.
6. The image noise processing apparatus of claim 5, wherein the processing module comprises: a determining submodule, configured to determine a parameter value of an effective pixel in the target column and a parameter value of the reference pixel; and the updating sub-module is used for carrying out difference on the parameter value of the effective pixel and the parameter value of the reference pixel, and updating the parameter value of the corresponding effective pixel according to the result obtained by the difference.
7. The image noise processing apparatus according to claim 5, further comprising: And the second determining module is used for determining the preset threshold according to the line number of the reference pixels.
8. The image noise processing apparatus according to claim 7, further comprising: And a third determining module, configured to determine an average value of the first difference value and the second difference value, and use the average value as a parameter value of the reference pixel.
9. An image sensor is provided, which is capable of detecting a light source, characterized by comprising the following steps: the image noise processing apparatus according to any one of claims 5 to 8.
10. A computer-readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the image noise processing method according to any one of claims 1-4.

Description

Image noise processing method and device, image sensor and storage medium Technical Field The present invention relates to the field of image processing technologies, and in particular, to an image noise processing method, an image noise processing device, an image sensor, and a storage medium. Background Fixed pattern noise in an image sensor can form more obvious stripes in the column direction after gain amplification, and eliminating or reducing the noise is one of important research points in the image sensor. The fixed pattern noise is basically positively correlated with the gain of the sensor, the fixed pattern noise is amplified by increasing the gain, the fixed pattern noise has a certain relation with the temperature, and the fixed pattern noise has different magnitudes at different temperatures. In the related art, a pixel for eliminating fixed pattern noise is generally obtained by making a difference between an effective pixel and an average value of black pixels in the same column. In this way, all column pixels are made bad, so that column fixed pattern noise cannot be accurately eliminated, the same operation is performed on columns without fixed pattern noise, and since the average value of black row pixels is not zero, effective pixels on columns without fixed pattern noise are lost, and the effect of the whole image is affected. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, an object of the present invention is to provide an image noise processing method, an image noise processing device, an image sensor, and a storage medium, which can perform noise cancellation processing only for column pixels having fixed pattern noise, avoid affecting column pixels not having fixed pattern noise, improve noise cancellation effects, and ensure image presentation effects. In order to achieve the above purpose, the image noise processing method according to the embodiment of the first aspect of the present invention includes obtaining a reference column in which a reference pixel having a preset feature in a pixel array is located, determining a position of the reference column in which fixed pattern noise exists from the reference column, and performing elimination processing on the fixed pattern noise of an effective pixel in a target column indicated by the position of the reference column in the pixel array. According to the image noise processing method provided by the embodiment of the first aspect of the invention, the reference column where the reference pixel with the preset characteristic is located in the pixel array is obtained, the position of the reference column with the fixed pattern noise is determined from the reference column, the fixed pattern noise of the effective pixel in the target column indicated by the position of the reference column is eliminated, the noise elimination process can be carried out only on the column pixel with the fixed pattern noise, the column pixel without the fixed pattern noise is prevented from being influenced, the noise elimination effect is improved, and the image presentation effect is ensured. In order to achieve the above object, an image noise processing device according to a second aspect of the present invention includes an acquisition module configured to acquire a reference column in which a reference pixel having a preset feature is located in a pixel array, a determination module configured to determine a position of the reference column in which fixed pattern noise exists from the reference column, and a processing module configured to perform elimination processing on the fixed pattern noise of an effective pixel in a target column indicated by the position of the reference column in the pixel array. According to the image noise processing device provided by the embodiment of the second aspect of the invention, the reference column where the reference pixel with the preset characteristic is located in the pixel array is obtained, the position of the reference column with the fixed pattern noise is determined from the reference columns, the fixed pattern noise of the effective pixel in the target column indicated by the position of the reference column is eliminated, the noise elimination process can be carried out only on the column pixel with the fixed pattern noise, the column pixel without the fixed pattern noise is prevented from being influenced, the noise elimination effect is improved, and the image presentation effect is ensured. In order to achieve the aim, the image sensor provided by the embodiment of the third aspect of the invention comprises the image noise processing device provided by the embodiment of the second aspect of the invention. According to the image sensor provided by the embodiment of the third aspect of the invention, the reference column where the reference pixel with the preset characteristic is located in the