A mixed triangular and quadrilateral partition for fractal image coding

This paper presents a new partitioning scheme for fractal image coding, based on triangles and quadrilaterals. The aim is to have the advantage of the triangles over the square and rectangular blocks, in terms of adaptivity to the image (reduction of the block effect), and to reduce the blocks number by grouping neighboring triangles into quadrilaterals. Quadrilaterals permit a reduction of the number of local contractive affine transformations composing the fractal transform, and thus to increase the compression ratio, while preserving the visual quality of the decoded image