can anybody explain regionprops with superpixels?

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Ad 2017-4-15

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评论： Ad 2017-4-20

I have generated 200 superpixels and used S=regionprops(L,'pixelList'); I got S= 196*1 struct value. How to access them and how do I know which one is column or row? help me is idx=label2idx(L); idx{i} helpful to access superpixel region?

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Image Analyst 2017-4-15

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With superpixels, row and column don't really have any meaning, do they? So don't think like that. You need to think about what you really want to do with the superpixels, or even if superpixels are what you really should be doing in the first place to process your image. Post your image and tell us what you want to do with it (like what you need to measure), and explain why you think superpixels is the best approach to accomplishing that. Maybe it is, but maybe it isn't - I don't know yet.

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Image Analyst 2017-4-17

在 MATLAB Online 中打开

Your first superpixel region has 1515 pixels in it. To get all the mean L values, you'd do

allLValues = [props.MeanIntensity]; % Extract from structure into array.
meanLValue = mean(allLValues);

Be careful with that though, because the superpixels may have different number of pixels in them so the mean as I showed above is not weighted by the area of each superpixel region. If you want the mean of the whole image, you can simply use mean2():

meanLOfWholeImage = mean2(I:,:,1);
meanAOfWholeImage = mean2(I:,:,2);
meanBOfWholeImage = mean2(I:,:,3);

I don't really know what it means to have the pixels lists of the whole image. Each superpixel will have a list of pixels in it. For the whole image, the pixel list will essentially just be every pixel in the whole image. If you want to access individual superpixel pixellists, you could do

for k = 1 : length(lprops)
    thisPixelList = lprops(k).PixelList; % No need to repeat for aprops and b props since they're the same pixel coordinates.
    thisPixelValuesL = lprops(k).PixelValues;
    thisPixelValuesA = aprops(k).PixelValues;
    thisPixelValuesB = bprops(k).PixelValues;
end