REGION-BASED TEXTURE CODING AT VERY LOW BITRATES

Anton Březina – Jaroslav Polec – Jarmila Pavlovičová –Ivana Kolingerová –Peter Bandzi

   Our approach to image region approximation offers a complete scheme consisting of few steps. The original image is segmented using two algorithms. An unsupervised colour - texture regions segmentation method (JSEG) and feature distributions based method. Following polygonal approximation of the created regions causes the region boundaries degradation. This approximation has no significant influence upon the image quality and allows increasing the code efficiency. Especially for very low bitrates image coding we achieved better values of objective quality criteria (PSNR). For texture approximation we use the 2D shape independent orthogonal transform (DCT II.). The encoding and decoding of polygons is very efficient because we need to store only their endpoints. The texture is coded with a modified code similar to JPEG arithmetic code.

Keywords: texture, segmentation, image compression, region-based coding

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