How can divide image with size 1704 x 2272 into 128 x 128 patches?

I have image with size 1704 x 2272. I divide the image into 128 x 128 patches. the output y is cell but the column 18 is empty as attached file. pls can u help me to solve that.

My code is

img = imread(filename)
img = rgb2gray(img);
img = size8cut(img);
y=preprocess5(img);

function Y=size8cut(X) % cut the rim of the image, to make it more fit to be cut into 128*128 patches

[m,n] = size(X);
if mod(m,8)~=0
    X=X(1:m-mod(m,8),:);
end
if mod(n,8)~=0
    X=X(:,1:n-mod(n,8));
end
Y=X;
end

function blkim=preprocess5(im)  % cut the image into image patch with 128*128 size
[m n]=size(im);
i = ceil(m/128);
j = ceil(n/128);
blkim=cell(i,j);
if i-1 ==0                 %%no zero dividsion
  overlap_m=0;
else
  overlap_m=(i*128-m)/(i-1);%compute the overlap between the patches
end
if j-1 ==0
  overlap_n=0;
else
  overlap_n=(j*128-n)/(j-1); 
end
if mod(overlap_m,8)~=0
  for count=1:32
     m=m-8;
     i=ceil(m/128);
     overlap_m=(i*128-m)/(i-1);
     if mod(overlap_m,8)==0
       break;
     end
   end
end

if mod(overlap_n,8)~=0
  for count=1:32
     n=n-8;
     j=ceil(n/128);
     overlap_n=(j*128-n)/(j-1);
     if mod(overlap_n,8)==0
        break;
     end
  end
end
im=im(1:m,1:n);
for ii=1:i
  for jj=1:j
      blkim{ii,jj}=im((128-overlap_m)*(ii-1)+1:(128-overlap_m)*(ii-1)+128,(128-overlap_n)*(jj-1)+1: (128-overlap_n)*(jj-1)+128);
   end
end
return;
end

[Jan]

Please read http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup for instructions to post readable code. Thanks.

[Jan]

@Ismail: I've added a proper indentation and removed the blank lines after each line of code to improve the readablility.

Answer 1

[Walter Roberson]

Use mat2cell if you do not need overlap. Use blockproc with a function of @(block) {block.data} if you need overlap, and remember to turn off border trim

[Ismail T. Ahmed]

Thanks.But my error in the code I want the answer and corrections on same code

[Jan]

@Ismail: Please post the complete error message by editing the original question.

[Ismail T. Ahmed]

I editted

[Walter Roberson]

Why do you want to use that code when you can do the task more easily? Is this an assignment where you are required to do it the way you are doing it? If so then are there any other requirements that people need to be aware of?

[Ismail T. Ahmed]

MY case is I have database contain more images but with different size.so I want divide each image into blocks with 128 x128 .pls how can do that?

[Image Analyst]

And why should the image size matter? As long as it will fit a 128x128 tile in there, what's the problem? If you need to handle partial tiles, then see the FAQ, like I've been suggesting, for a more general purpose/flexible solution.

[Walter Roberson]

With no overlap and not assuming complete tiling:

s1 = size(TheImage,1);
s2 = size(TheImage,2);

mat2cell(TheImage, [128 * ones(1, floor(s1/128)), mod(s1,128)], [128 * ones(1, floor(s2/128)), mod(s2,128)], size(TheImage,3))

The expression is a little simpler if you can be sure the images are multiples of 128 on a side:

 mat2cell(TheImage, 128 * ones(1, s1/128), 128 * ones(1, s2/128), size(TheImage,3))

Answer 2

[Image Analyst]

See the FAQ for code that works. http://matlab.wikia.com/wiki/FAQ#How_do_I_split_an_image_into_non-overlapping_blocks.3F

It's for non-overlapping blocks. If you need the blocks to overlap instead of being tiled or moving in "jumps" then there is a parameter in blockproc() that can control overlap.