Average image of a folder of images

I am trying to obtain the average image for this folder of multiple images.

My code is as shown, however there is an error -> thisImage=imread(files(k).myFolder);

myFolder='E:\FYP2\Time Frames\Frame 13';

if ~isdir(myFolder)
  errorMessage = sprintf('Error: The following folder does not exist:\n%s', myFolder);
  uiwait(warndlg(errorMessage));
  return;  
end

filePattern = fullfile(myFolder, '*.png');
theFiles = dir(filePattern);
numberOfImages=length(theFiles);
for k=1 : numberOfImages
  thisImage=imread(files(k).myFolder);
  [rows, columns, numberOfColorBands]=size(thisImage);
  if k == 1
    sumImage = thisImage;
  else
    sumImage = sumImage + thisImage;
  end
end
sumImage = sumImage / numberImages;

Answer 1

[Image Analyst]

Instead of this:

thisImage=imread(files(k).myFolder);

where

1. you did not include the folder when sending the filename to imread(), and
2. you did not use the right variable (files instead of theFiles) and
3. you did not have the right structure member off files (should be name, not myFolder),

try this:

fullFileName = fullfile(myFolder, theFiles(k).name);
thisImage=double(imread(fullFileName)); % Be sure to cast to double to prevent clipping.

[Gee Cheng Mun]

It finally works! The folder of images is actually PET scan images with red, yellow and green colored pixels. However, the average image obtained has changed into a white and magenta colored image. What I would like to have is actually an average of red, yellow and green pixels for all the images within the folder. What can I do?

[Image Analyst]

See my attached demo, which averages all gray scale or RGB images in a folder.

[Marcela pena]

Thanks for the script !!!