IEEE International Conference on Image Processing, September 2002


Generalized Bitplane-by-Bitplane Shift Method for JPEG2000 ROI Coding

 Zhou Wang, S. Banerjee, B. L. Evans and Alan C. Bovik

Laboratory for Image and Video Engineering (LIVE), Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX 78712-1084

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Abstract: One interesting feature of the upcoming JPEG2000 image coding standard is support of region of interest (ROI) coding using the maximum shift (Maxshift) method, which allows for arbitrarily shaped ROI image compression without shape coding or explicitly transmitting any shape information to the decoder. The major disadvantage of the Maxshift method is that it cannot adjust the scaling value which determines the degree of relative importance between the ROI and the background wavelet coefficients. The bitplane-by-bitplane shift (BbBShift) method was introduced to support both arbitrary ROI shape and arbitrary scaling without shape coding. In this paper, we propose a generalize BbBShift (GBbBShift) method, which delivers much more flexibility than both Maxshift and BbBShift for ``degree-of-interest" adjustment of the ROI with trivial reduction of coding efficiency and increase of computational complexity. Experiments show that it can provide significantly better visual quality than Maxshift at low bit rates. GBbBShift is not compliant with the current JPEG2000 definitions. In order to use it, a new ROI coding mode would need to be added to the standard.