ECE 563 Assignment 9

Submit html and MATLAB, as usual, on Isidore. Download images and other files from impro09.zip and seq.zip

1. Correct the three images of the front face of Kettering Lab for distortion. The image KLWall1.tif is shown below. Report the sign and magnitude of distortion used in each case.

   

2. Use an impulse image (isolated pixel of gray value one on a zero background image) to generate the impulse response for bilinear and bicubic interpolation using imresize. Plot a 3D mesh plot of the response function for each case.

3. Use imrotate to rotate an image by 22.5 degrees, and then use imresize to enlarge a cropped section of that image by a factor of 8. Pick a section with well-defined edges. Generate a 3 x 3 array of such images. Each column should use a different interpolation method for rotation. Each row should use a different interpolation method for resizing. The interpolation methods are nearest neighbor, bilinear, and bicubic interpolation.

4. Use the method of separable rotations, as given in class, for a rotation of 10 degrees and 80 degrees. Identify the problem that results for 80 degrees and provide a solution.

5. Here's an image of a bar code on a cylinderical product. Produce a rectified (non-distorted) version of this image.

   

6. Create a globe of the earth, using the matlab routine warp and the image ear0xuu2.jpg as the texture.

7. Assemble the images in seq.zip into a single mosaic by using matlab functions to determine the transformation between images. Here is one attempt at the mosaic:

   

8. Using a 24-bit color image, jpeg compress the image using quality factors of (5%, 10%, 15%, 25%, 50%, 75%, and 90%). Tabulate the file sizes and compression ratio achieved. Show the lower-quality images on your web page and compare to the original. Then convert the original image to grayscale repeat the compression versus jpeg quality factor table. Are the grayscale images 1/3 the size of the color images?

9. Prepare powerpoint presentations for the following image processing toolbox demos (See help - demos):
   1. group 1 - Exploring a conformal mapping
   2. group 2 - Padding and shearing an image simultaneously
   3. group 3 - Creating a gallery of transformed images
   4. group 4 - Finding Image Rotation and Scale
   5. group 5 - Registering an Image Using Normalized Cross-Correlation

   Submit powerpoint, published MATLAB, and original MATLAB and images. Only one submission needed per group. Use Isidore messages for submission.

Maintained by John Loomis, last updated 18 April 2016