Laplacian and sobel for image processing

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John Snow 2013-11-25

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评论： Image Analyst 2021-11-19

Hello im having trouble finding how to do the laplacian and sobel of an image I tried the following but none of the 2 results are like what is showed in the book The original image i'm working on is image (a)

Code I tried:

img = imread ('imagename'); A=[0 -1 0 ; -1 4 -1 ; 0 -1 0]; result1 = imfilter (img,A); result2 = conv2 (img,A);

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Here are the book results

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Image Analyst 2013-11-25

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test.m

Well you're not doing the Laplacian or Sobel. Try using the correct kernel and the correct function imgradient). Try the code I wrote for you below in blue.

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bini kif 2021-11-19

@Image Analyst in test.m

Image Analyst 2021-11-19

To make sure that the output values of hte convolution were in the same range as the input image. Otherwise, worst case where the center value is 255 and the outer values are zero then the output would be 8*255. That is more than the range of the input values. So just to make sure that case would get you a value of 255 instead of 8*255, I divided by 8.

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Bruno Pop-Stefanov 2013-11-25

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Make sure img is in right format. imfilter will work on a grayscale uint8 image. However, conv2 will only work on a double image. Use im2double to convert it.