index.md (992B)
1 +++ 2 title = 'Neighborhood processing' 3 +++ 4 # Neighborhood processing 5 Value of pixel in output is determined by value of same pixel in input and the neighbours. 6 7 Use small neighbourhood of pixel in input to get new brightness value in output. 8 9  10 11 ## Filtering (applying filter or mask to entire image): 12 13 - Mean filter — replace noise pixel by mean value of neighbours, including itself 14 - Median filter — order values in increasing order including itself, find median, set that as new value 15 16 ## Correlation/convolution in an image: 17 18 - works by scanning through image and applying mask (“kernel”) to each pixel 19 - kernel is filled with numbers, not always equal to one (“kernel coefficients”) 20 - coefficients weigh pixel value they are covering 21 - output of correlation is sum of weighted pixel values 22 - kernel alters center pixel 23 - decreases size of image! 24 25 example kernels: 26 27 