resize( ... , INTER_AREA ) - wrong scaling (Bug #921)

Hi,
when shrinking images with INTER_AREA, the scaling on the y-axis is wrong for some image/factor combinations.

It can easily be reproduced with this image
http://1bsbvthrwzq3cksa.1b.funpic.de/obskur.png
and the following code:

#include <opencv2/opencv.hpp>
using namespace cv;
int main() {
int boxSize( 10 );
double downScale( 1.0 / static_cast<double>(boxSize) );
Mat img = imread( "obskur.png" );
if ( !img.rows )
return 1;
Mat smallLinear;
Mat smallCubic;
Mat smallArea;
resize( img, smallLinear, Size(), downScale, downScale, INTER_LINEAR );
resize( img, smallCubic, Size(), downScale, downScale, INTER_CUBIC );
resize( img, smallArea, Size(), downScale, downScale, INTER_AREA );
namedWindow( "linear" );
namedWindow( "cubic" );
namedWindow( "area" );
imshow( "linear", smallLinear );
imshow( "cubic", smallCubic );
imshow( "area", smallArea );
waitKey();
destroyWindow( "linear" );
destroyWindow( "cubic" );
destroyWindow( "area" );
return 0;
}

Regards,
Dobias