Optimization of tone-mapping functions in video cameras for high dynamic range images

摘要

For real-time imaging with digital video cameras, good tonal rendition of video is important to ensure high visual comfort for the user. Except local contrast improvements, High Dynamic Range (HDR) scenes require adaptive gradation correction (tone-mapping function) which should enable good visualization of details at lower brightness. We discuss how to construct and control optimal tone-mapping functions, which enhance visibility of image details in the dark regions while not excessively compressing the image in the bright image parts. The result of this method is a 21-dB expansion of the dynamic range. The new algorithm was successfully evaluated in HW and although suited for any video system, it is particularly beneficial for those processing HDR video.