if, for loop, median
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hi, I am new to matlab programming. I wish to write a program involving image processing, which serves the following purpose: consider a 3x3 window in a normalised 512x512 image. Compare each value of the pixel with 0.3. If the value of image pixel is less than 0.3, sort the vector, and find the median of all the pixels with value less than 0.3. And if value is more than 0.3, neglect that pixel value, and find median of all remaining pixels which have values less than 0.3. All of this should result in a new image. Thanks and Regards Manpreet Kapoor
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Accepted Answer
Walter Roberson
on 11 Apr 2011
Is this 3 x 3 window to be slid overlapping over the whole image, or is the image to be broken up in to 3 x 3 blocks? If it is to be broken up in to 3 x 3 blocks, there is a problem because 512 is not divisible by 3.
You can use sorting to find the median if you want, but there is a median() function. For example, if P are the pixels in the window, then
median(P(P<0.3))
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Walter Roberson
on 11 Apr 2011
Sorry, I am not familiar with colfilt .
I would think it likely that blkproc() or blockproc() would be much faster than nlfilter.
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