Computer assignment 6 solution ee114 winter 100 150

Computer Assignment 6 Solution EE114, Winter 2014
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Figure 3 FT coefficients magnitude, reduced to [-128:127]
Typing
im_128 = real(ifft2(ft_128));
imagesc(im_128);
axis square;
PSNR(im, im_128)
yields the result in Figure 4 and a PSNR = 31.2383 .

EE114, Winter 2014 Computer Assignment 6 Solution
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Figure 4 Bridge, reconstructed from [-128,127]
2.3 Task c Reduce to [-64:63]
Typing
ft_64 = ReduceFT(ft, 64);
sft_64 = ScaleFTAmp(ft_64);
imagesc(sft_64); colormap(gray);
axis square;
yields the result in Figure 5.

Computer Assignment 6 Solution EE114, Winter 2014
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Figure 5 FT coefficients, reduced to [-64:63]
Typing
im_64 = real(ifft2(ft_64));
imagesc(im_64);
axis square;
PSNR(im, im_64)
yields the result in Figure 6 and a PSNR = 26.7170 .

EE114, Winter 2014 Computer Assignment 6 Solution
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Figure 6 Bridge, reconstructed from [-64,63]
2.4 Task c Reduce to [-32:31]
Typing
ft_32 = ReduceFT(ft, 32);
sft_32 = ScaleFTAmp(ft_32);
imagesc(sft_32); colormap(gray);
axis square;
yields the result in Figure 7.

Computer Assignment 6 Solution EE114, Winter 2014
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Figure 7 FT coefficients magnitude, reduced to [-32:31]
Typing
im_32 = real(ifft2(ft_32));
imagesc(im_32);
axis square;
PSNR(im, im_32)
yields the result in Figure 8 and a PSNR = 24.1756 .

EE114, Winter 2014 Computer Assignment 6 Solution
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Figure 8 Bridge, reconstructed from [-32:31]