Applying Threshold mask

i am making image compression in matlab.

After i applied DCT on image and i had img matrix, i want to apply a threshold mask on that matrix.

mask =     [1   1   1   1   0   0   0   0
            1   1   1   0   0   0   0   0
            1   1开发者_高级运维   0   0   0   0   0   0
            1   0   0   0   0   0   0   0
            0   0   0   0   0   0   0   0
            0   0   0   0   0   0   0   0
            0   0   0   0   0   0   0   0
            0   0   0   0   0   0   0   0];

maskedImg = blkproc(img,[8 8],mask );

I used that function but it didnt work and i get error message:

Error in ==> blkproc at 67 [a, block, border, fun, params, padval] = parse_inputs(varargin{:});

According to latest Matlab documentation; closest blockproc syntax (for your case) is B = blockproc(A,[M N],fun). So apparently your mask really should be a function!

However, I recall that blkproc has been a valid Matlab function for a while ago, thus double check the proper way to call it by typing (in the command line) > help blkproc. (Al tough I'm quite confident that it will share the calling signature with blockproc [in this case]).