function subsampled_image = mSubsampleAverage( image )

[ row_max, col_max ] = size( image );

subsampled_image = round( ( ...
                     image( 1:2:row_max, 1:2:col_max ) + image( 2:2:row_max, 1:2:col_max ) ...
                     + image( 1:2:row_max, 2:2:col_max ) + image( 2:2:row_max, 2:2:col_max ) ...
		          ) / 4 );