Graphics平移原点及向上向右方向为正方式变换

Image img = Image.FromFile(path);
using (var g = Graphics.FromImage(img))
{
	g.Transform = new System.Drawing.Drawing2D.Matrix(1, 0, 0, -1, 0, 0);//Y轴向上为正，X向右为正
	g.TranslateTransform(ox, oy, System.Drawing.Drawing2D.MatrixOrder.Append);//平移坐标原点
}