Spatio-temporal video contrast enhancement

A video contrast enhancement algorithm which automatically enhances the contrast of a video using spatial and temporal information is proposed. The algorithm is based on the observation that the contrast in a video frame can be improved by increasing the grey-level differences between each pixel of the video frame and its neighbouring pixels. Furthermore, such an improvement should be smooth in between consecutive video frames so that continuum of contrast improvement is achieved. A two-dimensional (2D) histogram of a video frame is constructed using mutual relationship between each pixel and its neighbouring pixels. For each video frame, a 2D target histogram is computed by considering 2D histogram of the video frame, 2D uniformly distributed histogram, and the 2D histograms of forward and backward neighbouring video frames. The contrast enhancement of the video frame is achieved by mapping the diagonal elements of the 2D input histogram to the diagonal elements of the 2D target histogram. The proposed algorithm is easy to implement and is thus suitable for real-time contrast enhancement applications.

[1]  Azeddine Beghdadi,et al.  Contrast enhancement technique based on local detection of edges , 1989, Comput. Vis. Graph. Image Process..

[2]  Abd. Rahman Ramli,et al.  Minimum mean brightness error bi-histogram equalization in contrast enhancement , 2003, IEEE Trans. Consumer Electron..

[3]  Shanq-Jang Ruan,et al.  Dynamic contrast enhancement based on histogram specification , 2005, IEEE Transactions on Consumer Electronics.

[4]  Turgay Çelik,et al.  Contextual and Variational Contrast Enhancement , 2011, IEEE Transactions on Image Processing.

[5]  Zia-ur Rahman,et al.  A multiscale retinex for bridging the gap between color images and the human observation of scenes , 1997, IEEE Trans. Image Process..

[6]  Sanjit K. Mitra,et al.  Enhancement of Color Images by Scaling the DCT Coefficients , 2008, IEEE Transactions on Image Processing.

[7]  Qian Chen,et al.  Image enhancement based on equal area dualistic sub-image histogram equalization method , 1999, IEEE Trans. Consumer Electron..

[8]  Yücel Altunbasak,et al.  A Histogram Modification Framework and Its Application for Image Contrast Enhancement , 2009, IEEE Transactions on Image Processing.

[9]  Yeong-Taeg Kim,et al.  Contrast enhancement using brightness preserving bi-histogram equalization , 1997 .

[10]  Gérard G. Medioni,et al.  A Framework for Robust Online Video Contrast Enhancement Using Modularity Optimization , 2012, IEEE Transactions on Circuits and Systems for Video Technology.

[11]  Sos S. Agaian,et al.  Transform Coefficient Histogram-Based Image Enhancement Algorithms Using Contrast Entropy , 2007, IEEE Transactions on Image Processing.

[12]  Zhongfu Ye,et al.  Flattest histogram specification with accurate brightness preservation , 2008 .

[13]  Eli Peli,et al.  Post Transmission Digital Video Enhancement for People with Visual Impairments. , 2006, Journal of the Society for Information Display.

[14]  V. Ranganath.  AUTOMATIC IMAGE EQUALIZATION AND CONTRAST ENHANCEMENT USING GAUSSIAN MIXTURE MODELING , 2014 .

[15]  Turgay Çelik,et al.  Two-dimensional histogram equalization and contrast enhancement , 2012, Pattern Recognit..

[16]  David Menotti,et al.  Multi-Histogram Equalization Methods for Contrast Enhancement and Brightness Preserving , 2007, IEEE Transactions on Consumer Electronics.

[17]  Rabab Kreidieh Ward,et al.  Fast Image/Video Contrast Enhancement Based on Weighted Thresholded Histogram Equalization , 2007, IEEE Transactions on Consumer Electronics.

[18]  C. E. SHANNON,et al.  A mathematical theory of communication , 1948, MOCO.