DCT_IDCT

代码说明：

  to understand the Algorithm go to matlab help in page dct2 and idct2 to get the mathematical expression for M = N = 8, we can calculate the most of hard values and save it as LUTs to speed up the execution now compare our special 8X8 functions with the internal general functions use this code: A = int32(100*rand(8,8)) tic for i = 1 : 1000 IDCT_8X8(DCT_8X8(A)) end toc tic for i = 1 : 1000 idct2(dct2(A)) end toc i had built the general functions too, but with low speed (to understand the Algorithm go to matlab help in page dct2 and idct2 to get the mathematical expressionfor M = N = 8, we can calculate the most of hard values and save it as LUTs to speed up the executionnow compare our special 8X8 functions with the internal general functionsuse this code: A = int32 (100* rand (8,8)) tic for i = 1: 1000 IDCT_8X8 (DCT_8X8 (A)) end toc tic for i = 1: 1000 idct2 (dct2 (A)) end toc i had built the general functions too, but with low speed)