Automatic adjustment method of color image brightness

Abstract

The invention discloses an automatic adjustment method of color image brightness. As for the problem of being excessively low or high of the brightness of a color image, although a certain detailed information exists at areas of the image which are too dark or bright, the areas of the image are unfavourable for an eye visual system to be distinguished, and as a result, a visual effect is poor, and it is of great necessity and great significance to adjust the brightness of the color image to an optimal sensing range of eyes. The automatic adjustment method of the invention includes the following steps that: 1) an original image is read; (2) the inputted image is converted to an HSV color space from a RGB color space; 3) the average background brightness of each pixel in a brightness component V is obtained through a background filter; 4) the brightness mean value of the whole filtered image is obtained; 5) the drawing coefficient of piecewise linear brightness drawing which is performed on the brightness component V can be obtained through utilizing the JND and the brightness mean value; 6) piecewise linear brightness drawing is performed on the on the brightness component V; and 7) the HSV color space is converted to the RGB color space, and a color image after brightness adjustment is outputted.

Description

technical field [0001] The invention belongs to the technical field of image processing and analysis, and more specifically relates to an automatic adjustment method for color image brightness. Background technique [0002] Human vision is divided into scotopic vision under low illuminance, photopic vision and intermediate vision under normal illuminance. Under scotopic conditions, the contrast resolution threshold of human vision is very low. Even if the contrast is relatively high in an image with too dark brightness, and the detailed information is relatively rich, it still cannot be detected because it cannot reach the threshold of contrast resolution of human vision. perceived by the human visual system. The human visual contrast resolution threshold is called JND (Just-noticeable difference). An image that is too bright is also not conducive to the human eye to distinguish details in a local area. The automatic adjustment of the brightness of the color image makes t...

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Problems solved by technology

And the image is too bright, which is not conducive to the human eye to distinguish the details in the local area.

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