How it is possible to change all images orientation to same i.e. to vertical

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Zara Khan 2018-6-21

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评论： Zara Khan 2018-6-24

My folder consisting of 1000 binary images with different orientation. I want to make all of them to vertically align. How it will be possible through a single code ? Later I want to save all the vertically aligned images to a new folder. Note:few images are already in vertical orientation . I want to keep them as it is .

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Guillaume 2018-6-21

How do you define the orientation of your image? Is it based on the content of the image (e.g. there's a line in the image) or simply on the size of the image (i.e it's taller than wide)?

Zara Khan 2018-6-21

I am finding images orientation by regionprops

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Answer 1

Image Analyst 2018-6-21

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https://ww2.mathworks.cn/matlabcentral/answers/406732-how-it-is-possible-to-change-all-images-orientation-to-same-i-e-to-vertical#answer_325643

在 MATLAB Online 中打开

regionprops() is not needed. Simply use size(). Rotate if the image is wider than tall:

[rows, columns, numberOfColorChannels] = size(yourImage);
if columns > rows
    yourImage= imrotate(yourImage, 90);
end

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Zara Khan 2018-6-22

编辑：Zara Khan 2018-6-22

在 MATLAB Online 中打开

Image Analyst: I am attaching few of my images here. Few images are already in vertically align(considering their orientation by regionprops). I want to set a condition where the program will leave those images as it is where they are already vertically align and will change rest images orientation to vertical which are having different orientations

    folder = 'D:\folder1';
% folder = pwd;
filepattern = fullfile(folder, '*.png');
srcFiles = dir(filepattern);
numImages = length(srcFiles);
for k = 1 : numImages
  fullFileName = fullfile(folder, srcFiles(k).name);
    a = imread(fullFileName);
    bwimg =bwareafilt(~a, 1); 
s1=regionprops(bwimg,'Orientation','Centroid');
angle = s1(1).Orientation;
angleToRotateBy = 90 - angle;
rotatedImage = imrotate(bwimg, angleToRotateBy);
verticalProfile = sum(rotatedImage, 2);
firstLine = find(verticalProfile > 0, 1, 'first');
lastLine = find(verticalProfile > 0, 1, 'last');
topSum = sum(verticalProfile(firstLine:firstLine+50));
bottomSum = sum(verticalProfile(lastLine-50:lastLine));
if topSum > bottomSum
  rotatedImage = imrotate(rotatedImage, 180);
end
path='D:\folder2\';
imwrite(rotatedImage,[path,num2str(k),'.png']);
end

Even I have tried your this above code too but not able to change all images orientation to the same.

Image Analyst 2018-6-23

编辑：Image Analyst 2018-6-23

在 MATLAB Online 中打开

It might not work because you did this extremely unwise thing:

path='D:\folder2\';

Never overwrite the MATLAB search path or you'll get into trouble! Once you fix that, it seems to work fine!

% Initialization steps.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;
% folder = 'D:\folder1';
folder = pwd;
filepattern = fullfile(folder, 'P*.png');
directoryInfo = dir(filepattern);
numImages = length(directoryInfo);
for k = 1 : numImages
  baseFileName = directoryInfo(k).name
  fullFileName = fullfile(folder, baseFileName);
  grayImage = imread(fullFileName);
  [rows, columns, numberOfColorChannels] = size(grayImage);
  if numberOfColorChannels > 3
    % It's not gray scale!  Convert to gray scale.
    grayImage = grayImage(:, :, 1); % Use red channel only.
  end
  % Bring up a new figure for each image.
  figure;
  subplot(2, 2, 1);
  imshow(grayImage, []);
  axis('on', 'image');
  title(baseFileName, 'FontSize', fontSize, 'Interpreter', 'none');
  drawnow;
  
  binaryImage = grayImage < 128;
  binaryImage = bwareafilt(binaryImage, 1); % Take largest blob only
  subplot(2, 2, 2);
  imshow(binaryImage, []);
  axis('on', 'image');
  title('Binary Image', 'FontSize', fontSize);
  drawnow;
  
  % Measure angle.
  props=regionprops(binaryImage, 'Orientation', 'Centroid');
  % Get slopes and angles.
  angle = props.Orientation
  angleToRotateBy = 90 - angle
  slope = tand(angle);
  
  % Draw line through centroid.
  xCentroid = props.Centroid(1);
  yCentroid = props.Centroid(2);
  hold on;
  plot(xCentroid, yCentroid, 'r*', 'MarkerSize', 13, 'LineWidth', 2);
  plot(xCentroid, yCentroid, 'ro', 'MarkerSize', 13, 'LineWidth', 2);
  % Fit line
  x = linspace(1, columns);
  y = -slope * (x - xCentroid) + yCentroid;
  % Clip y values to image
  y = max(y, 0);
  y = min(y, rows);
  line(x, y, 'Color', 'r', 'LineWidth', 2);
  drawnow;
  
  rotatedImage = imrotate(binaryImage, angleToRotateBy);
  verticalProfile = sum(rotatedImage, 2);
  firstLine = find(verticalProfile > 0, 1, 'first');
  lastLine = find(verticalProfile > 0, 1, 'last');
  topSum = sum(verticalProfile(firstLine:firstLine+50));
  bottomSum = sum(verticalProfile(lastLine-50:lastLine));
  if topSum > bottomSum
    rotatedImage = imrotate(rotatedImage, 180);
  end
  subplot(2, 2, 3);
  imshow(rotatedImage, []);
  axis('on', 'image');
  title('Rotated Image', 'FontSize', fontSize);
  drawnow;
  
  outputFileName = fullfile('D:\folder2\', [num2str(k),'.png'])
%   imwrite(rotatedImage,outputFileName);
end

I fancied it up a bit also, and improved the variable names to make them more descriptive.

Image Analyst 2018-6-23

You may have to put in some ad hoc code to recognize and handle pathological image, like ones that are too roundish. For example you may have to track the angle across frames and do something special if the angle changed too much from one frame to the next. Sorry, I can't write a turnkey and robust gesture recognition system for you - it's just way too much work.

Zara Khan 2018-6-24

okey. Thank you for your time and response.

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Answer 2

Matt J 2018-6-21

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https://ww2.mathworks.cn/matlabcentral/answers/406732-how-it-is-possible-to-change-all-images-orientation-to-same-i-e-to-vertical#answer_325690

Use imrotate() with the Orientation angle given by regionprops().

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Matt J 2018-6-21

Zara Khan commented:

I have already accessed and loaded them in matlab. But each image having different orientation and then how it will be possible to set all them to vertically align ? It is possible through a code ?