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 image enhancement method comprises the steps that the brightness value of an original image is extracted, a visibility threshold is determined, and a brightness enhanced image is determined through combination of light intensity of the environment in which display equipment is arranged. The gradient gain function of a display image is determined through combination of a just-noticeable-distortion model according to the light intensity of the environment in which the display equipment is arranged so that the enhanced display image under ambient light is acquired through a weighed optimization mode. A readability enhanced color display image is obtained through color spatial conversion. The brightness and the details of the display image are enhanced through a gradient domain optimization framework based on weighting so that readability of the display image under ambient light can be enhanced, the brightness of the display image is enhanced by using a nonlinear transfer function under ambient light, gradient loss caused by ambient light can be compensated by adopting the just-noticeable-distortion model, and finally readability of the image on the display equipment can be enhanced.

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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