/// <summary>
/// Computes the new image size.
/// </summary>
protected override Size CalculateNewImageSize(UnmanagedImage sourceData)
{
// Calculate source size
float w = sourceData.Width;
float h = sourceData.Height;
// Get the four corners and the center of the image
PointF[] corners =
{
new PointF(0, 0),
new PointF(w, 0),
new PointF(0, h),
new PointF(w, h),
new PointF(w / 2f, h / 2f)
};
// Project those points
corners = homography.Inverse().TransformPoints(corners);
// Recalculate image size
float[] px = { corners[0].X, corners[1].X, corners[2].X, corners[3].X };
float[] py = { corners[0].Y, corners[1].Y, corners[2].Y, corners[3].Y };
float maxX = Matrix.Max(px);
float minX = Matrix.Min(px);
float newWidth = Math.Max(maxX, overlayImage.Width) - Math.Min(0, minX);
float maxY = Accord.Math.Matrix.Max(py);
float minY = Accord.Math.Matrix.Min(py);
float newHeight = Math.Max(maxY, overlayImage.Height) - Math.Min(0, minY);
// Store overlay image size
this.imageSize = new Size((int)Math.Round(maxX - minX), (int)Math.Round(maxY - minY));
// Store image center
this.center = Point.Round(corners[4]);
// Calculate and store image offset
int offsetX = 0, offsetY = 0;
if (minX < 0)
{
offsetX = (int)Math.Round(minX);
}
if (minY < 0)
{
offsetY = (int)Math.Round(minY);
}
this.offset = new Point(offsetX, offsetY);
// Return the final image size
return(new Size((int)Math.Ceiling(newWidth), (int)Math.Ceiling(newHeight)));
}
