MATLAB: IMWRITE followed by IMREAD Changes Pixel Values

imageimage processing

I have an image matrix
aa        150x200x3            720000  double
With pixel values 0-255
Why does this test fail :
imwrite(aa, 'aatest.png');
aanew = imread('aatest.png');
isequal(aa, aanew)

Best Answer

I tried this, and I realized that ISEQUAL compares a DOUBLE and UINT8, which quite obviously does not return true.
 p = rand(150,200,3);
 imwrite(p,'test.png');
 pnew = imread('test.png');
 isequal(p,pnew)
if you really want to check equality,
 isequal(im2uint8(p),pnew)
is the way to go.
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