public Painter(WriteableBitmap filledImage, BitmapImage sourceImage)
{
this.filledImage = filledImage;
SourceImage = sourceImage;
this.sourceWidth = sourceImage.PixelWidth;
this.sourceHeight = sourceImage.PixelHeight;
this.stride = this.sourceWidth*BytesPerPixel;
this.sourceImageBytes = sourceImage.GetBytes();
this.patternImageBytes = filledImage.GetBytes();
this.sourcePatternImageBytes = new byte[this.patternImageBytes.Length];
this.patternImageBytes.CopyTo(this.sourcePatternImageBytes, 0);
}