Dynamic contrast automatic adjustment circuit and its adjustment method

Abstract

The present invention provides a dynamic contrast automatic adjustment circuit and its adjustment method. It first counts the number of points whose brightness is less than the low threshold and the number of points whose brightness is greater than the high threshold in the brightness input signal through the histogram statistical module, and then through the dynamic The parameter calculation module calculates each dynamic parameter according to the statistical results and the linear mapping curve, such as the mapping selection signal, and then increases or decreases the brightness input signal by a dynamic brightness offset signal through the dynamic brightness adjustment circuit to adjust it to the brightness input signal to be mapped, and finally The luminance input signal to be mapped is calculated point by point through the piecewise linear mapping module to obtain the luminance signal output after mapping. Through the present invention, the contrast of the video image is enhanced, and the definition of the picture quality is improved, and due to the present invention All adjustments are made in a gradual manner, and the human eye does not perceive flicker.

Description

Technical field [0001] The invention relates to a contrast adjustment circuit and an adjustment method thereof, in particular to a dynamic contrast automatic adjustment circuit and an adjustment method thereof that can automatically and dynamically adjust the contrast of an image. Background technique [0002] Nowadays, people have higher and higher requirements for video quality, and image contrast has become an important indicator of many electronic video equipment. Although the existing technology already has the function of manually adjusting the video contrast, when the gray level of the video data is distributed in the darker to the brighter gray, the contrast will not increase, but will decrease. There is even a problem of gray-scale merge. [0003] The prior art mostly adopts the method of gray-scale mapping curve to adjust the contrast according to the video image. The grayscale mapping curve method first determines the curve for grayscale mapping according to the histog...

AI Technical Summary

Problems solved by technology

However, there are some defects in this method: when the gray level distribution in the scene changes slightly, the scene detection will switch between various modes frequently, so that the image will flicker, and this method of curve mapping is not only dynamic The optional range of adjustment is limited, and because the table itself needs to be stored, the overhead is relatively large

[0004] To sum up, it can be seen that the dynamic contrast adjustment method of the prior art has the problems of image flickering, limited range of options for dynamic adjustment, and high overhead. Therefore, it is necessary to propose improved technical means to solve this problem

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