High dynamic range imaging optimization method and device

Abstract

The invention discloses a high dynamic range imaging optimization method and a device, which aim at increasing the brightness of insufficient exposure parts in a high dynamic range. In the invention, single-frame colorful images are used as a foundation; the information of other pixels in a certain scope surrounding a single pixel is used to implement accuracy judgment on whether the pixel exposure is sufficient or not; then the image is converted into a linear space; exposure compensation is implemented on the pixels with insufficient exposure to improve the brightness of the pixels with insufficient exposure and avoid color distortion possibly caused by directly improving the pixel values or possibly formed false details; besides, the whole treatment process is simple to operate and has low complexity. The invention is particularly suitable for being implemented on small devices with limited operation processing capacity like mobile phones, digital cameras, etc.

Description

technical field [0001] The invention relates to the field of digital image processing, in particular to a high dynamic range imaging optimization technology in image processing. Background technique [0002] In the process of image acquisition, since the dynamic range of the scene to be shot is greater than that of the shooting device, and only one global and fixed exposure method can be used for a single shot, only part of the scene in the scene to be shot can be correctly exposed. Other scenes are either overexposed or underexposed. Overexposure makes the scene appear bright and whitish, and underexposure makes the scene dark and black. [0003] In order to make all the scenes in the image look bright enough to obtain better visual effects, a common solution is to first obtain an image that allows the brighter parts of the scene to be correctly exposed, and at this time the darker parts of the scene are underexposed , appears dim in the obtained image; then remap all pix...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the large gain compensation for correctly exposed dark pixels in the prior art, the mapping curve used to increase the brightness cannot correctly reflect the nonlinear response of the shooting equipment to the light intensity, and the lack of false details on the original image, The present invention provides a high dynamic range imaging optimization method and its device. Based on a single-frame color image, the present invention uses the information of other pixels within a certain range around a single pixel to accurately judge whether the pixel is fully exposed, and then The image is converted into a linear space, and the underexposed pixels are compensated for exposure in the linear space. Finally, through nonlinear inverse mapping, the obtained new exposure is mapped into a new pixel value, which can improve its brightness while maintaining color and details. consistent with the original image

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