could you fix these codes?
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I=imread('filename');
a1=I(1:8,1:8);
a2=I(1:8,9:16);
a3=I(1:8,17:24);
a4=I(1:8,25:32);
b1=I(9:16,1:8);
b2=I(9:16,9:16);
b3=I(9:16,17:24);
b4=I(9:16,25:32);
c1=I(17:24,1:8);
c2=I(17:24,9:16);
c3=I(17:24,17:24);
c4=I(17:24,25:32);
d1=I(25:32,1:8);
d2=I(25:32,9:16);
d3=I(25:32,17:24);
d4=I(25:32,25:32);
could you tell me how to make it short? Thank you
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Jan
2013년 5월 14일
편집: Jan
2013년 5월 14일
Don't do this.
Hiding the index in the name of a variable is a bad programming pattern. It is much more efficient to use indices as indices:
img = reshape(a(1:32, 1:32), 8, 4, 8, 4);
img = permute(img, [1,3,2,4]);
Now you have img(:, :, 1, 1) instead of a1.
This is much faster, needs less memory, and allows to expand the method for millions of tiles easily.
댓글 수: 3
Image Analyst
2013년 5월 16일
You may not even need to do that. It's possible that you do not need to even store the tiles at all. Do you? Why do these tiles need to be stored rather than just operated on and thrown away (reused)? Just operate on one tile at a time if you can - why store forever?
추가 답변 (2개)
Iman Ansari
2013년 5월 14일
편집: Iman Ansari
2013년 5월 14일
Hi. Use cell array:
I=imread('moon.tif');
C=mat2cell(I(1:32,1:32),8*ones(1,4),8*ones(1,4));
imshow(C{5},'InitialMagnification','fit')
C{5} or C{1,2} is a2 in your code.
댓글 수: 3
Iman Ansari
2013년 5월 14일
It's not good having variable named a1,a2,..., see this:
I=imread('moon.tif');
C=mat2cell(I(1:32,1:32),8*ones(1,4),8*ones(1,4));
imshow(C{5},'InitialMagnification','fit')
C in this code is:
C={a1,a2,a3,a4;b1,b2,b3,b4;c1,c2,c3,c4;d1,d2,d3,d4}
and for s:
s=[C{1,1} C{2,1} C{3,2} C{4,3};C{1,3} C{2,2} C{3,3} C{4,4};...]
David Sanchez
2013년 5월 14일
You can try as well something like this
I=imread(your_32x32_image_name);
division = 8; % set according to yuor needs
L = size(I,1)/division;
subI = cell( L,L );
for row=1:L
for col=1:L
subI{row,col} = I( (row:row*division),(col:(col*division)) );
end
end
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