public static WriteableBitmap MakeSmallerCopy(this WriteableBitmap original, int maxDimension)
{
var ratio = 0.0;
if (original.PixelHeight > original.PixelWidth)
{
ratio = ((double)original.PixelHeight) / maxDimension;
}
else
{
ratio = ((double)original.PixelWidth) / maxDimension;
}
if (ratio > 1.0)
ratio = 1.0;
var newWidth = (int)Math.Floor(((double)original.PixelWidth) / ratio);
var newHeight = (int)Math.Floor(((double)original.PixelHeight) / ratio);
var toReturn = new WriteableBitmap(newWidth, newHeight);
toReturn.Blit(toReturn.BoundingRect(), original, original.BoundingRect());
return toReturn;
}