Explain briefly the operation, draw the functions, formulas and observations.
(i) Write an m-file "imnorm.m" which takes an image finds min and max values and uses them to normalize the image.
What kind of image enhancement operation is performed within that function? Draw an illustration.
Write an m-file for each of the following operations: (ii) compute negative image (neg.m)
(iii) apply power law transform with a superscript 0.2 (powlaw.m)
(iv) perform histogram equalization of an image (hist_eq.m) it should display 5 figures: the input image and its histogram the integral histogram the output image and its histogram the following function will give you a histogram of pixel values between 0 and 255 h=sum(hist(im,[0:255])'); %help hist; help sum; stem(h,'.k');
function imh=hist_eq(im); figure(1); imshow(?); h=? figure(2) stem(?); % compute integral image hint=h; for i=2:256 hint(i)=hint(i-1)+h(i); end hint=255*hint/hint(end); %normalize the integral histogram to have values between 0 and 255 figure(3) stem(?); imh=hint(im);%modify pixel intensities imh=uint8(imh);%normalize to byte values figure(4) imshow(?) h=? figure(5) stem(?);
What histogram equalization does? What should be the shape of the output histogram? Why it isn't?