Parallelization of a Loop with 'parfor - Unsuccessfully

Question

Royi Avital 2014-9-13

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/154613-parallelization-of-a-loop-with-parfor-unsuccessfully

评论： Matt J 2014-9-13

Hello, I created an algorithm which work on Image Patches. I go through matrix of an image and apply a function of a neighborhood predefined.

For some reason MATLAB won't allow me using the 'parfor' command.

Here is the code:

mInputFrames = padarray(mInputFrames, [searchWinEffRadius searchWinEffRadius], 'replicate');
parfor iRowIdx = 1:videoFramesNumRows
    for jColIdx = 1:videoFramesNumCols
        paddedImageRowIdx = iRowIdx + searchWinEffRadius;
        paddedImageColIdx = jColIdx + searchWinEffRadius;
          vSearchWindowRowIdx = [(paddedImageRowIdx - searchWinEffRadius):(paddedImageRowIdx + searchWinEffRadius)];
          vSearchWindowColIdx = [(paddedImageColIdx - searchWinEffRadius):(paddedImageColIdx + searchWinEffRadius)];
          for kFrameIdx = 1:videoFramesNumFrames
              vPatches = ((kFrameIdx - 1) * singleFrameSearchWindowNumPixels) + ...
                  [1:singleFrameSearchWindowNumPixels];
              mCurrSearchWindow           = mInputFrames(vSearchWindowRowIdx, vSearchWindowColIdx, kFrameIdx);
              mCurrSearchWindowPatches(:, vPatches) = Im2ColSliding(mCurrSearchWindow, [localWinSize, localWinSize]);
          end
          mOutputFrame(iRowIdx, jColIdx) = PatchFilter(mCurrSearchWindowPatches, refPixelRowIdx, refPixelColIdx, vGaussianKernel, weightsStd);
      end
  end

The error I'm getting: "The PARFOR loop cannot run due to the way variable 'mCurrSearchWindowPatches' is used.

The work on the loops is per pixel which is completely indepndent (In the result) from its neighborhood. What can I do to allow the parallelization to kick in?

Thank You.