Color image contrast enhancement method and system

Abstract

The invention discloses a color image contrast enhancement method comprising the following steps that a color image is read, and the coordinates of each pixel and the color component values thereof are acquired; the mean value of all the color component values is calculated so that mean image data are generated; edge-preserving smoothing filtering processing is performed on the mean image data; small scale mean filtering processing is performed; a pixel contrast enhancement coefficient is calculated according to contrast enhancement control parameters; all the color component values are enhanced according to the pixel contrast enhancement coefficient so that enhanced color component values are obtained; and clamping processing is performed on the enhanced color component values and then the enhanced color component values are outputted. Besides, the invention also discloses an enhancement system performing the method. The enhancement system comprises a reading module, a mean calculation module, a smoothing filtering processing module, a mean filtering processing module, an enhancement coefficient calculation module, an enhancement module and an output module. Processing in an RGB space can be performed directly, and only one time of key smoothing filtering processing is performed so that calculation is simplified and the effect of contrast enhancement is great.

Description

technical field [0001] The invention belongs to the field of image and video processing, in particular to a color image contrast enhancement method and system. Background technique [0002] Due to the influence of bad weather or the dark color of the scene itself, the contrast of the imaging picture is low, making the details of the scene in the image blurred and the definition insufficient. Therefore, image contrast enhancement is a basic operation widely used in the field of image processing. Its algorithm The complexity has an important impact on the real-time performance of practical engineering. [0003] The existing color image contrast enhancement methods are generally divided into two categories. One type of method is to convert color image data from RGB space to another color space, such as Lab space, and then convert the brightness data back to RGB space after contrast enhancement processing. The disadvantage of this type of method is that the multiple conversion...

AI Technical Summary

Problems solved by technology

The disadvantage of this type of method is that the multiple conversions of data cause an increase in computational complexity; another type of method is directly processed in the RGB space, such as the unsharp mask (USM) method in Photoshop software, through each color plane Contrast enhancement is carried out separately. The disadvantage of this method is that the calculation of multiple plane data will increase the calculation amount exponentially.

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