Tutorial 1

Question 1

Assume that humans have the ability to tell the gender and approximate age by looking at

the picture of an unknown person? If a computer can be made to have the same ability,

what kinds of information the computer must possess?

Question 2

Write a program to reduce the size of an image by half.

Question 3

Write a program to count the number of bright pixels (pixel value >= 200) in an image.

Tutorial 1 Solution

Question 2 function halfim % reduce the image size by half

image = imread('baboon64g.bmp'); imshow(image) [height, width] = size(image); y = 1; for i = 1:2:height x = 1; for j = 1:2:width halfimage(y, x) = image(i, j); x = x + 1; end y = y + 1; end figure imshow(halfimage) end

Question 3 function [count] = countbrightpixels % count the number of pixels >= 200

image = imread('lenna_gray.bmp'); [height, width] = size(image); count = 0; for i = 1:height for j = 1:width if image(i, j) >= 200 count = count + 1; end end end end