Illumination compensation by using singular value decomposition and discrete wavelet transform

This paper proposes a new illumination compensation technique based on iterative implementation of singular value equalization of low frequency subband of a given image. In this work, both input and reference images are decomposed into different frequency subbands by using discrete wavelet transform (DWT). Then low frequency subbands are used in order to compensate the illumination of the input image and achieve the same illumination of the reference image. Afterwards inverse DWT (IDWT) is used to reconstruct the illumination compensated image. The experimental results on various video resolution enhancement techniques show that maximum PSNR gain of 1.96 dB is achieved by applying the proposed illumination compensation technique.