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ECE468: HOMEWORK 2
due 01/
(20pts) Problems from the textbook: 3.11, 3.
(20pts) Write a MATLAB code for computing an affine transform of an image. The input to your program is: (i) image, (ii) parameters of the affine transform, and (iii) interpolation method. Your report should include:
a) M-file with a well commented code;
b) Figure 1 and the caption: Use the image for Problem 2 that is available on the class website as input, and transform it using the bilinear interpolation and the following spatial transform
x′ y′ 1
= T
x y 1
where
T =
c) Figure 2 and the caption: Use the image generated in Figure 1 as input to your code, and applying the inverse transform T −^1 to Figure 1 and the bilinear interpolation
x′′ y′′ 1
= T −^1
x′ y′ 1
d) Figure 3 and the caption: Subtract Figure 2 from the original image used in (b) (pad zeros at the boundary of Figure 2 in case the images have different sizes); In the caption, explain why Figure 2 is different from the original image.
(Hint: Use the following MATLAB commands: ’maketform’, ’imtransform’)
- (40pts) Write a MATLAB code for image sharpening using the Laplacian filter. The input to your program is: (i) image, and (ii) type of the Laplacian filter. Use the image for Problem 3 that is available on the class website as input. Your report should include:
a) M-file with a well commented code;
b) Figure 4 and the caption: Directly apply the 3 × 3 Laplacian filter with 8 at the center.
c) Figure 5 and the caption: First, smooth the original image by using the 3 × 3 Gaussian filter with σ^2 =. 5 , and then apply the 3 × 3 Laplacian filter with 4 at the center.
d) Figure 6 and the caption: First, smooth the original image by using the 3 × 3 Gaussian filter with σ^2 = 1, and then apply the 3 × 3 Laplacian filter with − 8 at the center.
e) Which sharpening procedure of the above is more visually appealing?
(Hint: Use the following MATLAB commands: ’imfilter’, ’fspecial’)
- (20pts) Write a MATLAB code for computing the correlation between two images. The input to your program is: (i) image 1, and (ii) image 2. Use the images for Problem 4 that are available on the class website as input. Your report should include:
a) M-file with a well commented code;
b) Figure 7 showing the correlation and the caption.
c) What are (x, y) coordinates of the maximum correlation?
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