A method of image enhancement under ambient light

Abstract

The invention discloses an image enhancement method under ambient light and belongs to the field of image processing. The invention includes extracting the brightness value of the original image, determining the visibility threshold, and determining the brightness-enhanced image in combination with the light intensity of the environment where the display device is located. According to the light intensity of the environment where the display device is located, the gradient gain function of the display image is determined based on the perceptible error model, and then the enhanced display image under ambient light is obtained through weighted optimization. After color space transformation, a color display image with enhanced readability is obtained. Through a weighted gradient domain optimization framework, the brightness and details of the displayed image are enhanced to improve the readability of the displayed image under ambient light. The nonlinear transfer function under ambient light is used to enhance the brightness of the displayed image, while using a just perceptible error model. To compensate for the gradient loss caused by ambient light, it ultimately enhances the readability of images on display devices.

Description

technical field [0001] The invention belongs to the field of image processing, in particular to an image enhancement method under ambient light. Background technique [0002] Recently, viewing conditions have become a hot issue in display technology research and have attracted considerable attention from display manufacturers. For example, the color temperature characteristic in lighting performance makes the displayed image appear reddish or bluish. In addition, it is often encountered that different lighting conditions change drastically, such as when the mobile phone is in the office and outdoors. As the light intensity increases the black level brightness of the display device, it will reduce the contrast, color and color gamut size of the display device; especially in daylight conditions, the image displayed on the mobile device will appear dark and lose a lot of detail information . Therefore, under strong outdoor conditions, obtaining images with high brightness, r...

AI Technical Summary

Problems solved by technology

[0005] Ambient light not only loses the contrast of the displayed image, but also loses the brightness of the displayed image

Especially under strong ambient light, the brightness loss is more serious than other losses, which will lead to the overall darkening of the displayed image, and cause a large amount of detail loss and contrast loss in the displayed image

At this time, simply using the brightness enhancement method will lead to the loss of details of the displayed image, and as the ambient light increases, the loss of details will become more obvious, reducing the readability of the displayed image

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