out of memory with [c,s]=wavedec2()

i apply wavelet transform for MP4 video, already i read the video and divide it to frames and divide each frame to each color channel and each color channel to 512*512 blocks, and apply wavedec2 to each block. how solve out of memory error in [c,s]=wavedec2(img,4,db2)?? the error exactly is:

 ??? Error using ==> conv2
Out of memory. Type HELP MEMORY for your options.

Error in ==> dwt2 at 94
  z = conv2(y,Hi_D(:)','valid');

Error in ==> wavedec2 at 66
  [x,h,v,d] = dwt2(x,Lo_D,Hi_D); % decomposition

Error in ==> WaveletTransform at 21
              [C,S]=wavedec2(img,nLevel,wname);

also it shouldn't have problem with AVI video. my MP4 video is short and 2 sec.

Answer 1

[Wayne King]

Are you saying that wavedec2() throws a memory error on a single call with a 512x512?

For example, this does not cause a memory issue:

 X = randn(512,512);
 [C,S] = wavedec2(X,4,'db2');

Are you sure that you are not somehow aggregating data in your img variable so that it is growing in your WavletTransform script?

[roya]

in fact i am using wavedec2() in nested loop which in each iteration it is applied for a block...i can show you here this part of my code:

[roya]

   for k=1:c
        for i=1:nbw
            for j=1:nbh
                img=im2double(Blocks{nFrame}{k}{i}{j});
                [C,S]=wavedec2(img,nLevel,wname);
                CS{nFrame}{k}{i}{j}{1}=C;
                CS{nFrame}{k}{i}{j}{2}=S;
                A=appcoef2(C,S,wname,nLevel);
                W{nFrame}{k}{i}{j}{1}=A;
                for ii=1:nLevel
                    [H,V,D]=detcoef2('all',C,S,ii);
                    W{nFrame}{k}{i}{j}{(nLevel-ii+1)*3-1}=H;
                    W{nFrame}{k}{i}{j}{(nLevel-ii+1)*3}=V;
                    W{nFrame}{k}{i}{j}{(nLevel-ii+1)*3+1}=D;

                end    
            end
        end

if true
  % code
end

[roya]

also i use the limited number of frames for example i assign "maxnumframe=10", but it doesn't work and same error. this code is ok for AVI video but not for MP4 video...:(