A method for transmitting image data sets via a communication network is provided. Image data are processed for dividing the image into a plurality of image sub regions and for determining for each of the plurality of the image sub regions a hash code in dependence upon pixel data of pixels located in the respective image sub region. The hash codes are transmitted together with location data of the respective image sub regions if the hash code exists in an associative dataset and the pixel data are transmitted together with location data of the respective image sub regions if the hash code does not exist in the associative dataset. Upon receipt of at least one of the hash codes and the pixel data together with the location data, image data are generated by performing at least one of: retrieving the pixel data from the associative dataset in dependence upon the received hash codes and placing the retrieved pixel data in the image in dependence upon the location data; and, placing the received pixel data in the image in dependence upon the location data.