% edges.m illustrates Matlab edge detection methods

F = 'party_72.png';                   % specify the file name

P = imread(F);                        % read image into M by N by 3 matrix
size(P)
class(P)

ED = edge(rgb2gray(P),'prewitt',0.05);% "prewitt" method w/ threshhold
imshow(ED)

size(ED)