Our approach to image region approximation offers a complete schemeconsisting of several steps. We separate the encoding of regionboundaries from the texture description. The original image is firstsegmented using an unsupervised segmentation method for color-textureregions. Following polygonal approximation of created regions causesthe degradation of region boundaries. The triangulation is then appliedto polygons and either all short edges, or all small triangles arefiltered out from the triangular mesh. This results in new smallerregions. The encoding and decoding of polygons and triangles is veryefficient, because we need to store only the vertices. For textureapproximation we use 2D shape independent orthogonal transforms (e.g.DCT II). The texture is encoded with a code similar to JPEG arithmeticcode. The encoding scheme proposed in this paper is much faster thanlatest approaches with polygonal approximation. We present the twotriangulation algorithms - constrained greedy (CGT) and constrainedDelaunay triangulation (CDT). Both CGT and CDT provide similar results
