convolution and filtering raed s. rasheed 2012. convolution and filtering – convolution is the...
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Convolution and Filtering
Raed S. Rasheed2012
Convolution and Filtering
– Convolution is the fundamental neighborhood operations of image processing.
– Used for filtering of images e.g., to suppress noise or enhance edges.
Convolution
– In convolution, the calculation performed at a pixel is a weighted sum of grey levels from a neighborhood surrounding a pixel. The neighborhood includes the pixel under consideration, and it is customary for it to be disposed symmetrically about that pixel.
Convolution
Convolution
Convolution
Convolution
– Computational problems • No processing at the border• Copying of input image pixels• Truncation of the image• Truncation of the kernel
Filtering
– Mean & Median filter• In which we select the middle-ranked value from a
neighborhood as our output value. For a 3x3 neighborhood, the middle value is fifth in the list of sorted grey levels; for an nxn neighborhood with n odd, the middle value is at position n2/2 + 1.
Filtering
Filtering
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