reading multiple images from a folder in Matlab

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yasmine
yasmine 2011-11-7
评论： Emily Leung 2021-6-18
I want to read many images from a folder in the Matlab directory using imread() and then make different operations in every image individually , i wrote this code but it disagrees about (+k+):
num_file=1;
file = dir('image.orig');
num_file = numel(file);
NF=num_file;
Y=1;Z=1;
images = cell(1,NF,T);
T=cell(Y,Z,3);
for k = 1:NF
images{1,k}(Y,Z,3) = imread('C:Work\image.orig\'+k-1+'.JPEG');
end
also, i want to save the matrix of each image in a cell array and i don't if what i wrote is right or not and i cannot have a permission to read from the folder, i checked the folder and found that it is read only, what do you think?
Thank you in advance

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Walter Roberson
Walter Roberson 2011-11-7
file = dir('image.orig');
NF = length(file);
images = cell(NF,1);
for k = 1 : NF
images{k} = imread(fullfile('image.orig', file(k).name));
end
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yasmine
yasmine 2011-11-10
This code was running the other day very good but now it gives no output and no errors , i changed the name of the folder but no good
is there anything in matlab i have to update or something, here is the code:
file = dir('image');
file = file(~[file.isdir]);
NF = length(file);
images = cell(NF,1);
for k = 1 : NF
disp(file(k).name);
images{k} = imread(fullfile('image', file(k).name));
end
Thank you
Walter Roberson
Walter Roberson 2011-11-10
I would put a breakpoint in and check each step -- for example, does file come out empty?
Check to be sure that you have not accidentally created your own dir.m or imread files:
which -all dir
which -all imread

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更多回答（4 个）

Image Analyst
Image Analyst 2011-11-8
It's always worth throwing in a plug for the FAQ: http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F
yasmine
yasmine 2011-12-8
Would you please help me : i'm dividing an image into blocks then making some analysis on each block i divided the image using mat2cell
now i want to convert each block into a numeric array but this error appears to me:
Assignment has more non-singleton rhs dimensions than non-singleton
subscripts
Here is the code:
nb(1) = ceil(256/ b(1)); % number of blocks in each dimension
nb(2) = ceil(384/ b(2)); % number of blocks in each dimension
C=mat2cell(images,ones(256/ b(1),1)*b(1),ones(384/ b(2),1)*b(2),3);% dividing the Image into blocks.
A= size(C);
m=1;
while (m < ((nb(1)*nb(2))+1))
for i=1:nb(1)%256
for j=1:nb(2)%384
A(i,j)=cell2mat(C{i,j});% here is the error
figure(1),subplot(nb(1),nb(2),m), image(A(i,j));
m=m+1;
end
end
end
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yasmine
yasmine 2011-12-9
yes i understand what you mean but i want to make a histogram for each block and when i did so :
for i=1:nb(1)%256
for j=1:nb(2)%384
[counts(i,j), x(i,j)] = imhist(C{i,j});
end
end
this error occurred:
??? Error using ==> iptcheckinput
Function IMHIST expected its first input, I or X, to be two-dimensional.
Error in ==> imhist>parse_inputs at 281
iptcheckinput(a,
{'double','uint8','int8','logical','uint16','int16','single','uint32', 'int32'}, ...
Error in ==> imhist at 59
[a, n, isScaled, top, map] = parse_inputs(varargin{:});
Error in ==> fll1 at 26
[counts(i,j), x(i,j)] = imhist(C{i,j});
so what do you think?
Walter Roberson
Walter Roberson 2011-12-9
I think this should definitely have gone in its own thread ;-)
You are trying to apply imhist() to a (subsection of) a truecolor image (which is thus a 3D matrix). imhist() is only for grayscale images. You should convert your whole image to grayscale before you break it up in to blocks; or you should convert each block to grayscale and imhist that as you go; or you should imhist() each of the three color planes separately.

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Shaveta Arora
Shaveta Arora 2016-4-9
If I have .tiff images and .tif images that I want to read, how they can be read ? I know how to read one type of images but how to read two types of images.
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Walter Roberson
Walter Roberson 2021-6-18
@Emily LeungIn the code I posted here, the filenames would come up empty if you do not have any .tif or .tiff files in the current directory.
In some cases, depending upon operating system configuration, files ending with extension .TIF or .TIFF might not be treated as if they ended in .tif or .tiff -- sometimes files are case sensitive.
The code I posted is not designed to look for files in a different directory; the changes to look in a different directory are not difficult though.
Emily Leung
Emily Leung 2021-6-18
@Walter Roberson i solved the issue, thank you very much this approach saved me many an if loop!

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Kumar Vaibhav
Kumar Vaibhav 2016-8-1
编辑：Walter Roberson 2016-8-1
I=imread(sprintf('C:/Users/kumar.vaibhav/Documents/MATLAB/Visually Similar Images/%d.jpeg',i));

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