New Post: WinRT Blit image quality

Hello,
I might not see the trees for the wood here. I have several smaller WriteableBitmaps and want to blit them into a larger one in a Windows Store 8.1 app.

When I copy pixel by pixel, I get the result on the right in the following image. When using Blit, I get the left one. Both sections are not the same but there is an obvious quality difference :-/. What am I doing wrong?

Any help appreciated.

Andreas



Source code:
Blit:

dest.DrawInto(backgroundImage, xDestOffset, yDestOffset, 0, 0, backgroundImage.PixelWidth, backgroundImage.PixelHeight);

 public static void DrawInto(this WriteableBitmap dest, WriteableBitmap backgroundImage, int xDestOffset, int yDestOffset, int xstart, int ystart, int xend, int yend)
{
  Rect destRect = new Windows.Foundation.Rect(xDestOffset, yDestOffset, xDestOffset + xend-xstart, yDestOffset + yend-ystart);
  Rect srcRect = new Windows.Foundation.Rect(xstart, ystart, xend-xstart, yend-ystart);
  dest.Blit(destRect, backgroundImage, srcRect, WriteableBitmapExtensions.BlendMode.None);
 }

Get/SetPixel:

 for (int x = 0; x < backgroundImage.PixelWidth; x++)
{
  if (x +xDestOffset >= dest.PixelWidth) {
    break;
  }
  for (int y = 0; y < backgroundImage.PixelHeight; y++)
  {
    if (y + yDestOffset >= dest.PixelHeight)
    {
      break;
    }
    var color = backgroundImage.GetPixel(x, y);
    dest.SetPixel(x+xDestOffset, y+yDestOffset, color);
  }
}