how to call multiple binary images in for loop?

Question

nitesh patil 2014-1-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/113139-how-to-call-multiple-binary-images-in-for-loop

评论： Image Analyst 2014-1-21

i am doing black pixel count in 9 images , so i created a for loop to perform count on each image one after other , please help me how to call 9 images one after other

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

AJ von Alt 2014-1-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/113139-how-to-call-multiple-binary-images-in-for-loop#answer_121645

编辑：AJ von Alt 2014-1-21

在 MATLAB Online 中打开

A cell array would be your best bet. Read each image in and store it as an element of the cell array. You can then iterate through the array in a loop.

Here's a quick example:

% Read in images and store them in a cell array
imarray{1} = imread('trees.tif');
imarray{2} = imread('trees.tif');
imarray{3} = imread('trees.tif');
imarray{4} = imread('trees.tif');
imarray{5} = imread('trees.tif');
imarray{6} = imread('trees.tif');
for i = 1:6
    % load each image and operate on it.
    currImage = imarray{i};
    % your code here 
end

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Amit 2014-1-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/113139-how-to-call-multiple-binary-images-in-for-loop#answer_121646

在 MATLAB Online 中打开

A = {'Image1.jpg','image2.jpg' ..... etc 'image9.jpg'}; % Store the names of all 9 image files.
for i = 1:9
  B = imread(A{i});
  _ Do you operation _
end

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 3

Image Analyst 2014-1-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/113139-how-to-call-multiple-binary-images-in-for-loop#answer_121651

在 MATLAB Online 中打开

See the FAQ for code samples: http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F. I don't think you need to create cell arrays to store the images, like the others suggested, unless you want to use them later for some reason.

myFolder = 'C:\Documents and Settings\yourUserName\My Documents\My Pictures';
if ~isdir(myFolder)
  errorMessage = sprintf('Error: The following folder does not exist:\n%s', myFolder);
  uiwait(warndlg(errorMessage));
  return;
end
filePattern = fullfile(myFolder, '*.jpg');
jpegFiles = dir(filePattern);
for k = 1:length(jpegFiles)
  baseFileName = jpegFiles(k).name;
  fullFileName = fullfile(myFolder, baseFileName);
  fprintf(1, 'Now reading %s\n', fullFileName);
  imageArray = imread(fullFileName);  
  % Note, imageArray is not a cell array, and is not being saved after the loop ends.
  imshow(imageArray);  % Display image.
  drawnow; % Force display to update immediately.
    % Now binarize the image and count black pixels.
    binaryImage = imageArray > thresholdValue; % which can be whatever value you want.
    sumOfBlackPixels(k) = sum(~binaryImage(:));
  end

Or, alternatively if you already have your 9 binary images (which is not very many), you can simply do it in 9 lines of code

sumOfBlackPixels(1) = sum(~binaryImage1(:));
sumOfBlackPixels(2) = sum(~binaryImage2(:));
sumOfBlackPixels(3) = sum(~binaryImage3(:));
sumOfBlackPixels(4) = sum(~binaryImage4(:));
sumOfBlackPixels(5) = sum(~binaryImage5(:));
sumOfBlackPixels(6) = sum(~binaryImage6(:));
sumOfBlackPixels(7) = sum(~binaryImage7(:));
sumOfBlackPixels(8) = sum(~binaryImage8(:));
sumOfBlackPixels(9) = sum(~binaryImage9(:));

2 个评论
显示无隐藏无

nitesh patil 2014-1-21

is it possible to perform alternative method using for loop instead 9 lines of sum operation?

Image Analyst 2014-1-21

Do you already have the 9 images before the for loop would start? If so, then you can't unless you load them into a cell array first (like amit and AJ showed you) and then do the for loop, which seems like more lines of code and an unnecessary complication. If you have some variable number of images - not always 9 - then you'll have to read them in in a for loop like the FAQ code above. But like I said, I wouldn't bother with a for loop unless you needed the images in some code after the for loop has finished. But if you do all your processing in the for loop, then no cells are needed.

See the FAQ for a good discussion of cells: http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F

请先登录，再进行评论。