An Efficient Metric for Evaluating the Quality of Color Image Enhancement M. C Hanumantharaju, M. Ravishankar, D. R Rameshbabu, V. N Manjunath Aradhya Department of Information Science and Engineering, Dayananda Sagar College of Engineering, Bangalore, India {mchanumantharaju,ravishankarmcn,bobrammysore,aradhya.mysore}@gmail.com Abstract. This paper describes a new metric for evaluating the quality of the color image enhancement. The image enhancement achieved by algorithms such as histogram equalization, adaptive histogram equaliza- tion, homomorphic filtering and Multiscale Retinex with Color Restora- tion (MSRCR) etc., improves the contrast, luminance and dynamic range compression. However, these algorithms introduces halo artifacts, vio- lates the gray world assumption and edge details of an image is lost. A major concern is that there is no accurate objective criterion for as- sessing the performance of image enhancement algorithms. Researchers developed some objective criteria such as Peak Signal to Noise Ratio (PSNR), contrast enhancement performance, luminance enhancement performance and Structural Similarity Measurement (SSIM) etc. How- ever, they could not solve the problem satisfactorily, and it often uses visual inspection and subjective criteria to evaluate the performance of these image enhancement algorithms. This paper proposes an objective and effective assessment criterion, Wavelet Energy (WE), to evaluate the performance of the color image enhancement algorithms. The proposed scheme describes both textual and structural information changes in an enhanced image. Numerous experiments were conducted to demonstrate the superiority of the proposed metric over the existing metrics. Exper- imental results confirm that the WE is an efficient and useful metric for evaluating the quality of the color image enhancement. Keywords: Objective Metric, Color Image Enhancement, Wavelet En- ergy, Peak Signal to Noise Ratio, Structural Similarity Measure. 1 Introduction Image enhancement is one of the important preprocessing step in digital image processing. Nowadays color image enhancement has become significant research area due to the widespread use of color images in many applications. The goal