2.tif 3.tif 4.tif 5.tif 6.TIF 7.tif 8.tif flowgraph_forward_dct.m flowgraph_inverse_dct.m image_8x8_block_flowgraph_forward_dct.m image_8x8_block_flowgraph_inverse_dct.m main.m PSNR.m