Low-illumination image processing method and device

Abstract

The invention provides a low-illumination image processing method and device. A noise suppression filter is additionally arranged before operation of contrast enhancement by aiming at a problem of noise amplification existing in an original low-illumination image contrast enhancement technology, and smoothing is performed on the inverse color image of a low-illumination image by adopting a first filtering coefficient and a second filtering coefficient so that image contrast is enhanced and random noise is suppressed simultaneously. Texture and noise level parameters of the image are calculated according to the local block interior characteristics of the image. Weighted averaging is performed on a first smooth image and a second smooth image after smoothing according to the texture and the noise level parameters. A texture image is obtained by performing texture structure extraction on the gradient image of the inverse color image, and the texture image is combined with the weighted image and the weighted image is sharpened so that the effect of enhancing image details can be realized. Therefore, contrast of the low-illumination image can be effectively enhanced, various types of noise can be filtered, the image color and details can be retained and thus a clear and lifelike restored image can be obtained.

Description

technical field [0001] The present application relates to the field of digital image processing, in particular to a low-illuminance image processing method and device. Background technique [0002] People are increasingly using surveillance cameras to ensure the safety of cities, traffic, public places, etc., and vehicle cameras are also used to improve driving safety. However, low-light conditions (such as night, backlight, indoors, etc.) will greatly reduce the performance of such cameras, making the images and videos captured by them less visible, and it is often difficult to identify key people, objects and other information. The images taken under the above conditions are called low-illumination images. Low-illumination images have various noises, which will become more prominent after image enhancement, thereby reducing the recognizability of the objects of interest in the image and strongly reducing people's subjective feelings. [0003] For traditional image enhance...

AI Technical Summary

Problems solved by technology

[0007] This application provides a low-illuminance image processing method and device, which solves the problems of noise amplification and detail loss after low-illuminance image processing

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