MATLAB: How to sort images from the smallest to the largest distance from the selected image ? the distances(histogram:Euclidean metric)

digital image processingframeimage processingvideo processing

Hi everybody. I am new matlab programmer.

My project is video Processing. I have xylopfone.mpg than How can i select image in xylopfone.mpg ?

other question How to sort images from the smallest to the largest distance from the selected image in xylophone.mpg ? the distances euclidean metric

Best Answer

https://www.mathworks.com/help/matlab/ref/videoreader.html

See the example https://www.mathworks.com/help/matlab/import_export/read-video-files.html

For determining the frame with the smallest "distance", calculate mse (mean squared error) of each frame compared to the selected frame. You can use the two-output form of min() to determine which frame had the lowest value.

Related Solutions

MATLAB: Converting video to frames

Try this demo. That is one of the things it does:

% Demo macro to extract frames and get frame means from an avi movie
% and save individual frames to separate image files.
% Also computes the mean gray value of the color channels.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
imtool close all;  % Close all imtool figures.
clear;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
fontSize = 14;
% Change the current folder to the folder of this m-file.
% (The line of code below is from Brett Shoelson of The Mathworks.)
if(~isdeployed)
  cd(fileparts(which(mfilename)));
end
% Open the rhino.avi demo movie that ships with MATLAB.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
movieFullFileName = fullfile(folder, 'rhinos.avi');
% Check to see that it exists.
if ~exist(movieFullFileName, 'file')
  strErrorMessage = sprintf('File not found:\n%s\nYou can choose a new one, or cancel', movieFullFileName);
  response = questdlg(strErrorMessage, 'File not found', 'OK - choose a new movie.', 'Cancel', 'OK - choose a new movie.');
  if strcmpi(response, 'OK - choose a new movie.')
    [baseFileName, folderName, FilterIndex] = uigetfile('*.avi');
    if ~isequal(baseFileName, 0)
      movieFullFileName = fullfile(folderName, baseFileName);
    else
      return;
    end
  else
    return;
  end
end
try
  videoObject = VideoReader(movieFullFileName)
  % Determine how many frames there are.
  numberOfFrames = videoObject.NumberOfFrames;
  vidHeight = videoObject.Height;
  vidWidth = videoObject.Width;
  numberOfFramesWritten = 0;
  % Prepare a figure to show the images in the upper half of the screen.
  figure;
%   screenSize = get(0, 'ScreenSize');
  % Enlarge figure to full screen.
  set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
  
    % Ask user if they want to write the individual frames out to disk.
    promptMessage = sprintf('Do you want to save the individual frames out to individual disk files?');
    button = questdlg(promptMessage, 'Save individual frames?', 'Yes', 'No', 'Yes');
    if strcmp(button, 'Yes')
        writeToDisk = true;
          % Extract out the various parts of the filename.
          [folder, baseFileName, extentions] = fileparts(movieFullFileName);
          % Make up a special new output subfolder for all the separate
          % movie frames that we're going to extract and save to disk.
          % (Don't worry - windows can handle forward slashes in the folder name.)
          folder = pwd;   % Make it a subfolder of the folder where this m-file lives.
          outputFolder = sprintf('%s/Movie Frames from %s', folder, baseFileName);
          % Create the folder if it doesn't exist already.
          if ~exist(outputFolder, 'dir')
              mkdir(outputFolder);
          end
      else
          writeToDisk = false;        
      end
      % Loop through the movie, writing all frames out.
    % Each frame will be in a separate file with unique name.
    meanGrayLevels = zeros(numberOfFrames, 1);
    meanRedLevels = zeros(numberOfFrames, 1);
    meanGreenLevels = zeros(numberOfFrames, 1);
    meanBlueLevels = zeros(numberOfFrames, 1);
      for frame = 1 : numberOfFrames
      % Extract the frame from the movie structure.
      thisFrame = read(videoObject, frame);
      
          % Display it
          hImage = subplot(2, 2, 1);
          image(thisFrame);
          caption = sprintf('Frame %4d of %d.', frame, numberOfFrames);
          title(caption, 'FontSize', fontSize);
          drawnow; % Force it to refresh the window.    
    % Write the image array to the output file, if requested.
        if writeToDisk
             % Construct an output image file name.

            outputBaseFileName = sprintf('Frame %4.4d.png', frame);
            outputFullFileName = fullfile(outputFolder, outputBaseFileName);
              % Stamp the name and frame number onto the image.
              % At this point it's just going into the overlay, 
              % not actually getting written into the pixel values.
              text(5, 15, outputBaseFileName, 'FontSize', 20);
              % Extract the image with the text "burned into" it.
              frameWithText = getframe(gca);
              % frameWithText.cdata is the image with the text
              % actually written into the pixel values.
              % Write it out to disk.
              imwrite(frameWithText.cdata, outputFullFileName, 'png');
          end
    % Calculate the mean gray level.
    grayImage = rgb2gray(thisFrame);
    meanGrayLevels(frame) = mean(grayImage(:));
    % Calculate the mean R, G, and B levels.
    meanRedLevels(frame) = mean(mean(thisFrame(:, :, 1)));
    meanGreenLevels(frame) = mean(mean(thisFrame(:, :, 2)));
    meanBlueLevels(frame) = mean(mean(thisFrame(:, :, 3)));
    % Plot the mean gray levels.
    hPlot = subplot(2, 2, 2);
        hold off;
    plot(meanGrayLevels, 'k-', 'LineWidth', 2);
        hold on;
        plot(meanRedLevels, 'r-');
        plot(meanGreenLevels, 'g-');
        plot(meanBlueLevels, 'b-');
        grid on;
    
        % Put title back because plot() erases the existing title.
    title('Mean Gray Levels', 'FontSize', fontSize);
        if frame == 1
      xlabel('Frame Number');
      ylabel('Gray Level');
            % Get size data later for preallocation if we read
            % the movie back in from disk.
            [rows columns numberOfColorChannels] = size(thisFrame);
        end
          % Update user with the progress.  Display in the command window.
          if writeToDisk
          progressIndication = sprintf('Wrote frame %4d of %d.', frame, numberOfFrames);
          else
          progressIndication = sprintf('Processed frame %4d of %d.', frame, numberOfFrames);
          end
      disp(progressIndication);
      % Increment frame count (should eventually = numberOfFrames
      % unless an error happens).
      numberOfFramesWritten = numberOfFramesWritten + 1;
      
      % Now let's do the differencing
      alpha = 0.5;
      if frame == 1
        Background = thisFrame;
      else
        % Change background slightly at each frame
  %       Background(t+1)=(1-alpha)*I+alpha*Background
        Background = (1-alpha)* thisFrame + alpha * Background;
      end
      % Display the changing/adapting background.
      subplot(2, 2, 3);
      imshow(Background);
      title('Adaptive Background', 'FontSize', fontSize);
      % Calculate a difference between this frame and the background.
      differenceImage = thisFrame - uint8(Background);
      % Threshold with Otsu method.
      grayImage = rgb2gray(differenceImage); % Convert to gray level
      thresholdLevel = graythresh(grayImage); % Get threshold.
      binaryImage = im2bw( grayImage, thresholdLevel); % Do the binarization
      % Plot the binary image.
      subplot(2, 2, 4);
      imshow(binaryImage);
      title('Binarized Difference Image', 'FontSize', fontSize);
      end
      % Alert user that we're done.
      if writeToDisk
          finishedMessage = sprintf('Done!  It wrote %d frames to folder\n"%s"', numberOfFramesWritten, outputFolder);
      else
          finishedMessage = sprintf('Done!  It processed %d frames of\n"%s"', numberOfFramesWritten, movieFullFileName);
      end
      disp(finishedMessage); % Write to command window.
      uiwait(msgbox(finishedMessage)); % Also pop up a message box.
      % Exit if they didn't write any individual frames out to disk.
      if ~writeToDisk
          return;
      end
      % Ask user if they want to read the individual frames from the disk,
      % that they just wrote out, back into a movie and display it.
      promptMessage = sprintf('Do you want to recall the individual frames\nback from disk into a movie?\n(This will take several seconds.)');
      button = questdlg(promptMessage, 'Recall Movie?', 'Yes', 'No', 'Yes');
      if strcmp(button, 'No')
          return;
      end
      % Read the frames back in, and convert them to a movie.
      % I don't know of any way to preallocate recalledMovie.
      for frame = 1 : numberOfFrames
          % Construct an output image file name.
          outputBaseFileName = sprintf('Frame %4.4d.png', frame);
          outputFullFileName = fullfile(outputFolder, outputBaseFileName);
          % Read the image in from disk.
          thisFrame = imread(outputFullFileName);
          % Convert the image into a "movie frame" structure.
          recalledMovie(frame) = im2frame(thisFrame);
      end
      % Get rid of old image and plot.
      delete(hImage);
      delete(hPlot);
      % Create new axes for our movie.
      subPlot(1, 3, 2);
      axis off;  % Turn off axes numbers.
      title('Movie recalled from disk', 'FontSize', fontSize);
      % Play the movie in the axes.
      movie(recalledMovie);
      % Note: if you want to display graphics or text in the overlay
      % as the movie plays back then you need to do it like I did at first
      % (at the top of this file where you extract and imshow a frame at a time.)
      msgbox('Done with this demo!');
catch ME
  % Some error happened if you get here.
  stError = lasterror;
  strErrorMessage = sprintf('Error extracting movie frames from:\n\n%s\n\nError: %s\n\n)', movieFullFileName, stError.message);
  uiwait(msgbox(strErrorMessage));
end

MATLAB: Matlab does not recognize the hasFrame for input type VideoReader

isaironi - according to hasFrame, this function was introduced in version R2014b so you will need at least that version in order to make use of it. (If you are using an earlier version of MATLAB, you will probably have an issue with the http://www.mathworks.com/help/matlab/ref/videoreader.readframe.htm readframe> function too.)

As an alternative, try the following

 numFrames = get(vidObj,'NumberOfFrames');
 for k=1:numFrames
    s(k).cdata = read(vidObj,k);
 end

Best Answer

Related Solutions

MATLAB: Converting video to frames

MATLAB: Matlab does not recognize the hasFrame for input type VideoReader

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