Removing rogue spatial frequencies from and image
I am currently working through an exercise and am at lost to how to remove the rouge pixels or as the question implies change them to a different colour I believe.
Here is the question, I have screen capture so no misspelling are made.
Q part 1
Q part 2
So here is my code so far
A=imread('coins.png');
x=1:size(A,2); y=1:size(A,1); [X,Y]=meshgrid(x,y);
noise= 30.*cos(2.*pi.*X./15 + 2.*pi.*Y./20);
B=double(A) + noise;
%subplot(1,2,1), imshow(A)
%subplot(1,2,2), imagesc(B); axis image; axis image;
D = fftshift(fft2(B));
E=imagesc(log(abs(D)));colormap gray
plot(abs(D))
Plot of frequency
As you can see from my plot there are two peak next to the central peak, these are the peak that I have to remove. But my issue I cant figure a way on how to implement my idea.
My idea is that if I take the central value and the two end point of each peak and find the row and column I can set it to zero and run it in a loop which will zero out all the element in the peaks, the issue is I cant figure a way into implementing this in a loop or if statement and wondering if someone could maybe advise and guide me though.
matlab image-processing matlab-figure
edited Jan 5 at 21:24
marc_s
573k12811071255
asked Nov 14 '18 at 20:54
james2018james2018
32
add a comment |
I am currently working through an exercise and am at lost to how to remove the rouge pixels or as the question implies change them to a different colour I believe.
Here is the question, I have screen capture so no misspelling are made.
Q part 1
Q part 2
So here is my code so far
A=imread('coins.png');
x=1:size(A,2); y=1:size(A,1); [X,Y]=meshgrid(x,y);
noise= 30.*cos(2.*pi.*X./15 + 2.*pi.*Y./20);
B=double(A) + noise;
%subplot(1,2,1), imshow(A)
%subplot(1,2,2), imagesc(B); axis image; axis image;
D = fftshift(fft2(B));
E=imagesc(log(abs(D)));colormap gray
plot(abs(D))
Plot of frequency
As you can see from my plot there are two peak next to the central peak, these are the peak that I have to remove. But my issue I cant figure a way on how to implement my idea.
My idea is that if I take the central value and the two end point of each peak and find the row and column I can set it to zero and run it in a loop which will zero out all the element in the peaks, the issue is I cant figure a way into implementing this in a loop or if statement and wondering if someone could maybe advise and guide me though.
matlab image-processing matlab-figure
edited Jan 5 at 21:24
marc_s
573k12811071255
asked Nov 14 '18 at 20:54
james2018james2018
32
I did try to change the from RGB to grey using RGB2grey(E) but I got an error the only other way round was to use imagesc(...;colormap grey) but to me that only displays the image in grey not change it.
– james2018
Nov 15 '18 at 11:35
add a comment |
I am currently working through an exercise and am at lost to how to remove the rouge pixels or as the question implies change them to a different colour I believe.
Here is the question, I have screen capture so no misspelling are made.
Q part 1
Q part 2
So here is my code so far
A=imread('coins.png');
x=1:size(A,2); y=1:size(A,1); [X,Y]=meshgrid(x,y);
noise= 30.*cos(2.*pi.*X./15 + 2.*pi.*Y./20);
B=double(A) + noise;
%subplot(1,2,1), imshow(A)
%subplot(1,2,2), imagesc(B); axis image; axis image;
D = fftshift(fft2(B));
E=imagesc(log(abs(D)));colormap gray
plot(abs(D))
Plot of frequency
As you can see from my plot there are two peak next to the central peak, these are the peak that I have to remove. But my issue I cant figure a way on how to implement my idea.
My idea is that if I take the central value and the two end point of each peak and find the row and column I can set it to zero and run it in a loop which will zero out all the element in the peaks, the issue is I cant figure a way into implementing this in a loop or if statement and wondering if someone could maybe advise and guide me though.
matlab image-processing matlab-figure
edited Jan 5 at 21:24
marc_s
573k12811071255
asked Nov 14 '18 at 20:54
james2018james2018
32
I am currently working through an exercise and am at lost to how to remove the rouge pixels or as the question implies change them to a different colour I believe.
Here is the question, I have screen capture so no misspelling are made.
Q part 1
Q part 2
So here is my code so far
A=imread('coins.png');
x=1:size(A,2); y=1:size(A,1); [X,Y]=meshgrid(x,y);
noise= 30.*cos(2.*pi.*X./15 + 2.*pi.*Y./20);
B=double(A) + noise;
%subplot(1,2,1), imshow(A)
%subplot(1,2,2), imagesc(B); axis image; axis image;
D = fftshift(fft2(B));
E=imagesc(log(abs(D)));colormap gray
plot(abs(D))
Plot of frequency
As you can see from my plot there are two peak next to the central peak, these are the peak that I have to remove. But my issue I cant figure a way on how to implement my idea.
My idea is that if I take the central value and the two end point of each peak and find the row and column I can set it to zero and run it in a loop which will zero out all the element in the peaks, the issue is I cant figure a way into implementing this in a loop or if statement and wondering if someone could maybe advise and guide me though.
matlab image-processing matlab-figure
matlab image-processing matlab-figure
edited Jan 5 at 21:24
marc_s
573k12811071255
asked Nov 14 '18 at 20:54
james2018james2018
32
edited Jan 5 at 21:24
marc_s
573k12811071255
asked Nov 14 '18 at 20:54
james2018james2018
32
edited Jan 5 at 21:24
marc_s
573k12811071255
edited Jan 5 at 21:24
marc_s
573k12811071255
edited Jan 5 at 21:24
marc_s
573k12811071255
573k12811071255
asked Nov 14 '18 at 20:54
james2018james2018
32
asked Nov 14 '18 at 20:54
james2018james2018
32
asked Nov 14 '18 at 20:54
james2018james2018
32
32
I did try to change the from RGB to grey using RGB2grey(E) but I got an error the only other way round was to use imagesc(...;colormap grey) but to me that only displays the image in grey not change it.
– james2018
Nov 15 '18 at 11:35
add a comment |
I did try to change the from RGB to grey using RGB2grey(E) but I got an error the only other way round was to use imagesc(...;colormap grey) but to me that only displays the image in grey not change it.
– james2018
Nov 15 '18 at 11:35
I did try to change the from RGB to grey using RGB2grey(E) but I got an error the only other way round was to use imagesc(...;colormap grey) but to me that only displays the image in grey not change it.
– james2018
Nov 15 '18 at 11:35
I did try to change the from RGB to grey using RGB2grey(E) but I got an error the only other way round was to use imagesc(...;colormap grey) but to me that only displays the image in grey not change it.
– james2018
Nov 15 '18 at 11:35
add a comment |
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I did try to change the from RGB to grey using RGB2grey(E) but I got an error the only other way round was to use imagesc(...;colormap grey) but to me that only displays the image in grey not change it.
– james2018
Nov 15 '18 at 11:35