Adaptive Local Power-Law Transformation for Color Image Enhancement

Color image enhancement is a very important process that has significantly impacted many portable devices, including PDAs, digital cameras, and mobile camera phones. Due to the limited memory space and computational power of portable devices, reducing the computational complexity of an embedded system is priority concern. Thus, this paper proposes an adaptive local power-law transformation method with low computational complexity and high performance. In order to reduce the computational time, a fast method is proposed to compute the local mean from the neighboring pixels to adapt the exponential value in the power-law transformation for enhancing the color images. The experiments reported included various color images; the results show that the performance of the proposed method is better than the compared global and local enhancement methods in terms of both non-over enhancement and natural color clearly revealed. In particular, the proposed enhancement method has low computational cost. Moreover, the proposed algorithm can be run on an embedded environment and processed in a real-time system due to its simplicity and efficiency