Dynamic contrast enhancement device and method

Abstract

The invention relates to a dynamic contrast enhancement device and a dynamic contrast enhancement method. The device comprises a color space switching module, a histogram statistical module, an enhanced mapping function module and a brightness transformation module, wherein the color space switching module is used for switching an input image data from a red, green and blue (RGB) color space to aluma and chroma (YUV) color space; the histogram statistical module is used for counting a gray histogram of an image according to a brightness component Y; the enhanced mapping function module is used for calculating weights of a plurality of brightness component intervals in the histogram and obtaining an adaptive mapping function f according to the designed mapping table of each brightness component interval and the weights; and the brightness transformation module is used for transforming the brightness Y of the image to a novel brightness Y' according to the adaptive mapping function f, and outputting the brightness in the RGB color space through the color space switching module. By the device, the image is divided into the plurality of brightness component intervals, the weights arecalculated respectively, and the adaptive mapping function is obtained by a weighting method to transform the image brightness; therefore, the processed image can keep a mean brightness, the contrastis effectively improved, and the problems of level reduction and details loss caused by the traditional histogram equalization are solved.

Description

technical field [0001] The present invention relates to the technical field of image processing, in particular to a device and method for dynamic contrast enhancement in post-processing of video images. Background technique [0002] Contrast, in simple terms, is the ratio of the display's white brightness to black brightness. Under the same white / black brightness, the higher the contrast, the more vivid the picture layering. [0003] Generally speaking, the greater the contrast, the clearer and more eye-catching the image, and the brighter and brighter the color. High contrast is very helpful for the clarity, detail performance and gray level performance of the image. Products with high contrast have more obvious advantages in details, clarity and high-speed moving objects in some dark scenes. And low contrast will make the picture gray and lose details. Especially in color images, since the brightness component is closely related to other color components, such as saturat...

AI Technical Summary

Problems solved by technology

[0011] The technical problem to be solved by the present invention is to provide a dynamic contrast enhancement device and method for the defects such as loss of details and over-enhancement caused by the histogram equalization used in the existing contrast enhancement, which can self-adaptively enhance the image, and Different images adopt different enhancement modes to achieve the best enhancement effect

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