I want to split an image into several pieces and automatically save them without needing to crop them manually. How can I do that?

Currently I'm using this code to split an image and save them. But I need to crop the split image manually before I save them. I'm doing this way because I don't want any white border around my image. So I'm trying to write a code where The image will be cropped automatically according to given dimension and save as cropped. Can anyone help to get there? I'm currently using this code:

clf;
clear all;
I = imread('Image1-Filter-segmented.tif');
[r c]= size(I);
A11=I(1:1*r/12,1:1*c/7);
A12=I(1:1*r/12,1*c/7:2*c/7);
A13=I(1:1*r/12,2*c/7:3*c/7);
A14=I(1:1*r/12,3*c/7:4*c/7);
A15=I(1:1*r/12,4*c/7:5*c/7);
A16=I(1:1*r/12,5*c/7:6*c/7);
A17=I(1:1*r/12,6*c/7:7*c/7);
imshow(A11);
crop=imcrop;
imwrite(crop,'A11.tif');
imshow(A12);

[DGM]

You should be able to simply save each of the A11 - A17 using imwrite(). If there are some sort of variable-width margins in each of those subimages, it may be simple enough to automatically crop them off, depending on what the image content is. It would help if you attach an example of the parent image. Since it's a TIFF file, you may have to zip it before the site will let you attach it.

You may also see if this helps:

https://www.mathworks.com/matlabcentral/answers/23921-remove-white-space-from-around-image#answer_825324

[Image Analyst]

"But I need to crop the split image manually ...... The image will be cropped automatically......"

So, which is it? How do you want to do it: manually or automatically? If automatic, how many tiles across and down do you want?

[Mohammad Nazmus Saquib]

I want 10 tites across down. It doesn't matter though if I can parametrize it and change it later according to necessity.

[Mohammad Nazmus Saquib]

@DGM I tried with the remove whitespace function. It helps. Thanks.

Answer 1

[yanqi liu]

clc;clear all;close all;
I = imread('cameraman.tif');
[r, c]= size(I);
A11=I(1:1*round(r/12),1:round(1*c/7));
A12=I(1:1*round(r/12),round(1*c/7):round(2*c/7));
A13=I(1:1*round(r/12),round(2*c/7):round(3*c/7));
A14=I(1:1*round(r/12),round(3*c/7):round(4*c/7));
A15=I(1:1*round(r/12),round(4*c/7):round(5*c/7));
A16=I(1:1*round(r/12),round(5*c/7):round(6*c/7));
A17=I(1:1*round(r/12),round(6*c/7):round(7*c/7));

% display
sz = size(I);
[x, y] = meshgrid(linspace(1,sz(2),8), linspace(1,sz(1),13));
y(y>r/12+1) = NaN;
z = ones(size(x));
figure;
imshow(I, []);
hold on; axis off;
mesh(x, y, z, 'FaceColor', 'none', ...
    'EdgeColor', 'r', 'LineWidth', 1);

% save
for i = 1 : 7
    imwrite(eval(sprintf('A1%d',i)), sprintf('A1%d.tif', i));
end

[Mohammad Nazmus Saquib]

Thanks. It helps. I was able to modify it for later stages too.

[x, y] = meshgrid(linspace(1,sz(2),8), linspace(round(r/12),sz(1),12));

y(y>round(2*r/12)+1) = NaN;

[DGM]

This doesn't even answer the question about cropping the images.

[Mohammad Nazmus Saquib]

@yanqi liu if I want to save the split parts into a different folder, is there any idea what to do? Currently I'm trying this but it saves in the original directory.

folder_name = 'r1';

if ~exist(folder_name, 'dir')

mkdir(folder_name);

end

for i = 1 : 7

filepath = fullfile(folder_name);

imwrite(eval(sprintf('A1%d',i)), sprintf('A1%d.tif', i));

end

[yanqi liu]

yes，sir，may be use this

clc;clear all;close all;
I = imread('cameraman.tif');
[r, c]= size(I);
A11=I(1:1*round(r/12),1:round(1*c/7));
A12=I(1:1*round(r/12),round(1*c/7):round(2*c/7));
A13=I(1:1*round(r/12),round(2*c/7):round(3*c/7));
A14=I(1:1*round(r/12),round(3*c/7):round(4*c/7));
A15=I(1:1*round(r/12),round(4*c/7):round(5*c/7));
A16=I(1:1*round(r/12),round(5*c/7):round(6*c/7));
A17=I(1:1*round(r/12),round(6*c/7):round(7*c/7));

% display
sz = size(I);
[x, y] = meshgrid(linspace(1,sz(2),8), linspace(1,sz(1),13));
y(y>r/12+1) = NaN;
z = ones(size(x));
figure;
imshow(I, []);
hold on; axis off;
mesh(x, y, z, 'FaceColor', 'none', ...
    'EdgeColor', 'r', 'LineWidth', 1);
% save the split parts into a different folder
folder_name = 'r1';
if ~exist(folder_name, 'dir')
    mkdir(folder_name);
end
for i = 1 : 7
    filepath = fullfile(folder_name);
    imwrite(eval(sprintf('A1%d',i)), fullfile(folder_name,sprintf('A1%d.tif', i)));
end

Answer 2

[DGM]

Without further information, this is a basic example using the following image.

I = imread('letterscatter.png');

tiling = [2 4]; % [tilesdown tilesacross]
framerange = [1 8]; % which tiles to save

padcolor = 255; % presumed border color to crop off
tol = 5; % color tolerance

% tiling order is row-wise
tilesize = [size(I,1) size(I,2)]./tiling
C = mat2cell(I,repmat(tilesize(1),1,tiling(1)),repmat(tilesize(2),1,tiling(2))).';
for f = 1:prod(tiling)
    % find the minimal box enclosing all pixels which aren't the padding color
    cdiff = abs(padcolor-C{f})>tol;
    rmap = any(cdiff,2);
    cmap = any(cdiff,1);
    rrange = find(rmap,1,'first'):find(rmap,1,'last');
    crange = find(cmap,1,'first'):find(cmap,1,'last');
    
    % crop
    thisframe = C{f}(rrange,crange);
    
    % save
    fname = sprintf('frame_%02d.tif',f);
    imwrite(thisframe,fname)
    
    % show
    imshow(thisframe)
    pause(0.5)
end