XE33PVR::Assignment 1

1. Write a simple Matlab showimage.m script that performs the following simple experiment.

   • Convert image to grayscale. The grayscale value are to be computed as an average over the R,G,B channels. Consider to use the Matlab functions mean or sum.
   • Add a constant to each of the grayscale values.
   • Display the maximum values for images.
   • Display the images by using the functionsimage, imagesc, imshow.

   Do all displaying functions work? Discuss the results? What is the reason for different behavior? Write your analysis to your script in form of comments.

   Grading: [1 point(s)] for correct analysis
   

2. Write a Matlab funtion compareim.m that compares two images and returns binary image with "1" in those pixels where the difference will be grater than a specified threshold. If im1,im2 are color images return "1" in positions where any of the color channel differences is grater than a threshold.

   Specifications: [binim,maskedim]=compareim(im1,im2,thr)

   • im1,im2 input images
   • thr threshold
   • binim binary image according to specification above
   • maskedim masked im2. All pixels that similar to im1 will be zeroed, will be black. Only the different pixels will be shown.

   The function should be robust. It should correctly handle incompatible input parameters, for instance if im1 and im2 have different number of pixels. See the Matlab function error.

   Grading: [3 point(s)] for a complete functionality if im1,im2 are grayscale images. 4 points for complete functionality on color images.
   

3. General comments. The programming style will also be evaluated. All your scripts and comments shuold be properly commented.

4. Pack your working directory with all images, codes and upload to the upload_system .