Method and device for reducing fixed pattern noise of image sensor in digital domain

Abstract

The invention provides a method of reducing fixed pattern noise of an image sensor in a digital domain. The method comprises steps: in a test environment, pixel data for at least one test picture are accessed; the average value of at least one part of pixel data for the at least one test picture in each row is calculated; and the average value in each row is used as a correction value for image data in each row in a normal light source environment to reduce the fixed pattern noise of the image sensor. The invention also provides a device for reducing the fixed pattern noise of the image sensor in the digital domain. By adopting the method and the device of the invention, the fixed pattern noise of the image sensor can be reduced.

Description

technical field [0001] The invention relates to a noise elimination mechanism in the field of image sensing, in particular to a method and device for reducing fixed pattern noise of an image sensor. Background technique [0002] Generally speaking, a traditional image sensor has the non-ideal effect of the analog circuit, which causes noise on the image sensing screen. For example, noise from non-ideal effects of analog circuits may include fixed pattern noise on the screen, that is, the phenomenon of straight lines on the sensing screen, which is caused by traditional sensor arrays. Leakage currents lead to inconsistencies in the signal characteristics of each straight-line circuit, causing straight lines to appear on the final sensing screen. In addition, the stray capacitance in traditional image sensors also easily causes each straight-line circuit to be affected when the analog signal is switched. Interference causes the signal characteristics of each direct circuit to...

AI Technical Summary

Problems solved by technology

[0002] Generally speaking, a traditional image sensor has the non-ideal effect of the analog circuit, resulting in the presence of noise on the image sensing screen.

For example, noise from non-ideal effects of analog circuits may include fixed pattern noise on the screen, that is, the phenomenon of straight lines on the sensing screen, which is caused by traditional sensor arrays. Leakage current, resulting in inconsistent signal characteristics of each straight-line circuit, resulting in a straight line phenomenon on the final sensing screen. In addition, the stray capacitance in the traditional image sensor is also easy to cause each straight-line circuit to be affected when the analog signal is switched. Interference causes the signal characteristics of each direct circuit to be inconsistent, and this is also one of the causes of fixed pattern noise

Furthermore, the analog circuit of the traditional image sensor also has other noises (such as random noise), which will also affect the image sensing screen

In order to reduce the noise caused by the non-ideal effect of the analog circuit in the current existing technology, the noise elimination circuit is usually implemented in the analog domain to reduce the noise. However, such a circuit design will be too complicated, and the circuit cost is also high

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