2A-L5 gradient direction quiz code

% Gradient Direction function result = select_gdir(gmag, gdir, mag_min, angle_low, angle_high) % TODO Find and return pixels that fall within the desired mag, angle range result = gmag >= mag_min & angle_low <= gdir & gdir <= angle_high; endfunction pkg load image; %% Load and convert image to double type, range [0, 1] for convenience img = double(imread('octagon.png')) / 255.; %imshow(img); % assumes [0, 1] range for double images %% Compute x, y gradients [gx gy] = imgradientxy(img, 'sobel'); % Note: gx, gy are not normalized %imshow((gx + 4) / 8);%or imshow(gx, [-4 4]) or imshow(gx, []) or imagesc(gx) %imshow((gy + 4) / 8); %% Obtain gradient magnitude and direction [gmag gdir] = imgradient(gx, gy); %imshow(gmag / (4 * sqrt(2))); % mag = sqrt(gx^2 + gy^2), so [0, (4 * sqrt(2))] %imshow((gdir + 180.0) / 360.0); % angle in degrees [-180, 180] %% Find pixels with desired gradient direction my_grad = select_gdir(gmag, gdir, 1, 30, 60); % 45 +/- 15 imshow(my_grad); % NOTE: enable after you've implemented select_gdir