Image processing method and image processing device for high dynamic range image

Abstract

The invention discloses an image processing method and an image processing device for a high dynamic range image. The method comprises the following steps: obtaining the high dynamic range image; collecting a brightness value of each pixel in the high dynamic range image; obtaining a first maximum brightness value and a first preset brightness value; according to the first preset brightness value, obtaining a first type of pixels and a second type of pixels from the pixels of the high dynamic range image; obtaining a first mapping curve according to each first type of pixels; obtaining a second mapping curve according to each second type of pixels, wherein the second mapping curve is continuous with the first mapping curve; and mapping the high dynamic range image according to the first mapping curve and the second mapping curve to obtain a target low dynamic range image. According to the image processing method, the compressed target low-dynamic-range image can display rich details in the high-dynamic-range image, and meanwhile, the requirement of image processing on hardware equipment is lowered.

Description

technical field [0001] The present invention relates to the technical field of image processing, in particular to an image processing method and an image processing device for high dynamic range images. Background technique [0002] The dynamic range reproduced by digital images is an important factor affecting image quality. Many devices, such as digital cameras and camcorders, cannot render scenes with high dynamic range (HDR) well. For example: for a person standing in front of a window indoors on a sunny day, when the exposure of the portrait is correct, the scenery outside the window is usually overexposed; when the scenery outside the window is correctly exposed, the portrait is very dark. [0003] In order to simultaneously present the portrait in front of the window and the scenery outside the window, an image processing method is proposed in the prior art: multiple frames of low dynamic range images with different dynamic ranges are synthesized into one frame of hi...

AI Technical Summary

Problems solved by technology

When performing histogram statistics on images with such a high dynamic range, if the interval of the histogram is too small, the amount of calculation in the data processing process will be huge, and the hardware requirements of the device are very high. For real-time and weak computing power Portable devices such as digital cameras and camcorders are difficult to meet the hardware requirements; if the interval of the histogram is too large, the compressed low dynamic range image will lose a lot of dark details, resulting in the displayed image unable to retain the rich details in the original high dynamic range image

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