Image contrast enhancement in compressed wavelet domain

This paper presents a new and efficient framework for image contrast and color enhancement in the compressed wavelet domain such as JPEG 2000. The proposed approach is capable of improving both global and local contrast as well as preserving color consistency. The framework does not require inverse transform for image enhancement since linear scale factors are directly applied to both scaling and wavelet coefficients in the compressed domain, which results in high computational efficiency. Also contaminated noise in the image can be efficiently reduced by introducing wavelet shrinkage terms adaptively in the different scales. Experimental results show that the proposed method can enhance wavelet-coded image computationally efficiently with high image quality and less noise or other artifact.