code: private ImageFormat getFormat(List<ImageFormat> l, String n){
  		for(ImageFormat f:l)
  			if(f.getName().equals(n))
  				return f;
  		return null;
  	}
docs: this method returns a format in a list given its name
  @param l the image format list
  @param n the name of the format
  @return the image format with the given name, or null