Image Processing Reference
In-Depth Information
Function edges=roberts(image)
%Find all edges by roberts cross operator
%
%Usage: [new image]=roberts(image)
%
%Parameters: image-array of points
%
%Author: Mark S. Nixon
%get dimensions
[rows, cols]=size(image);
%set the output image to black
edges=zeros (rows, cols);
for x=1: cols-1 %address all columns
except right border
for y=1: rows-1 %address all rows
except bottom border
%top right minus bottom left point
M_plus=abs(image (y,x+1)-image (y+1, x));
%top left minus bottom right point
M_minus=abs(image(y,x)-image (y+1, x+1));
%return maximum
edges(y,x)=max(M_plus, M_minus);
end
end
Eye edges by Roberts cross operator
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Edges by Roberts operator
disp (' ')
disp ('The Prewitt operator includes smoothing in horizontal and
vertical')
disp ('templates')
prewitt_edges=prewitt(eye);
disp ('From these, we calculate the magnitude and direction. The
magnitude')
disp ('shows the amount of contrast, as revealed by its image')
pmagnitude=prewitt_edges(:,:,1);
subplot (1,2,1), imagesc(pmagnitude);
