Application of nonlinear pre- and post-processing in low bit rate, error resilient image communication

The low bit rate, error resilience image coding method proposed here takes into account the content of an image and yields the least amount of degradation, caused by data loss, in those areas of the image which are of greater interest. This is achieved by employing a non-linear geometrical transform to add redundancy mainly to the region of interest (ROI). The non-linear transformation increases the ratio of pixels in the ROI to the total number of pixels in the image. This increased redundancy for ROI yields a high-quality reconstruction of ROI even with missing data. Simulations show that this approach has acceptable performance. Moreover, the method proposed here can be implemented through pre- and post-processing of the image data, without modification to the source codecs (e.g., JPEG). (C) 2003 Elsevier B.V. All rights reserved.