Reference-based local color distribution transformation method and its application to image integration

Abstract

We propose a reference-based filtering method that transforms the local color distribution of individual image patches. With our method, the color of a reference image is transformed by patch-wise color transformation so that it comes close to a noisy input image. Our method can be regarded as an extended version of reference-based filtering methods, such as guided image filtering and our previously proposed linear local color distribution transformation (LCDT). The main contribution is to enable more flexible transformation, which is required in some applications, e.g., flash/no-flash image integration and high dynamic range (HDR) image generation. We also propose an efficient framework for HDR image generation which is particularly suitable for generation of dark scenes without loss of image contrast. Experimental results show that the proposed quadratic LCDT achieves more robust color transformation, even in flash/no-flash image integration, and it was confirmed that the proposed framework based on quadratic LCDT is effective in HDR image generation.