coins = imread('coins.png');
coins_sp = imnoise(coins, 'salt & pepper', 0.02);
coins_median = medfilt2(coins_sp);
boxfilter = ones(3, 3) / 9;
coins_mean = imfilter(coins_sp, boxfilter);
%figure (1), imshow(coins);
%figure (2), imshow(coins_sp);
%figure (3), imshow(coins_median);
%figure (4), imshow(coins_mean);

rice = imread('rice.png');
rice_size = size(rice);
imgPyramid = impyramid(rice, 'reduce');
imgPyramid_size = size(imgPyramid);
imgPyramid1 = impyramid(imgPyramid, 'reduce');
imgPyramid1_size = size(imgPyramid1);
imgPyramid2 = impyramid(imgPyramid1, 'reduce');
imgPyramid2_size = size(imgPyramid2);
%figure (5), imshow(rice);
%figure (6), imshow(imgPyramid);
%figure (7), imshow(imgPyramid1);
%figure (8), imshow(imgPyramid2);

circuit = imread('circuit.tif');
circuit_edge1 = edge(circuit, 'Sobel');
circuit_edge2 = edge(circuit, 'Prewitt');
figure (9), imshow(circuit);
figure (10), imshow(circuit_edge1);
figure (11), imshow(circuit_edge2);
coins_Sobel = edge(coins, 'Sobel');
coins_Canny = edge(coins, 'Canny');
figure (12), imshow(coins);
figure (13), imshow(coins_Sobel);
figure (14), imshow(coins_Canny);