在矩形下反转1bbp颜色

Question

我正在使用GDI +,我正在使用的图像是一个1bbp的图像.我想做的是在图像上绘制一个矩形,该矩形下的所有内容都将被反转(白色像素将变为黑色,黑色像素变为白色).

我见过的所有示例代码都是针对8位RGB色阶图像,我不认为他们使用的技术对我有用.

这是我到目前为止的代码.这是父控件,其中一个Epl2.IDrawableCommand将是执行反转的命令.

public class DisplayBox : UserControl
{
    (...)
    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);
        (...)
            using (Bitmap drawnLabel = new Bitmap((int)((float)Label.LabelHeight * _ImageScaleFactor), (int)((float)Label.LableLength *(int) _ImageScaleFactor), System.Drawing.Imaging.PixelFormat.Format1bppIndexed))
            {
                using (Graphics drawBuffer = Graphics.FromImage(drawnLabel))
                {
                    (...)
                    foreach (Epl2.IDrawableCommand cmd in Label.Collection)
                    {
                        cmd.Paint(drawBuffer);
                    }
                    (...)
                }
            }
        }
    }
}
public class InvertArea : IDrawableCommand
{
    (...)
    public Rectangle InvertRectangle {get; set;}
    public void Paint(Graphics g)
    {
        throw new NotImplementedExecption();
    }
}

我应该Paint(Graphic g)为此命令添加什么？

Answer 1

诀窍是再次绘制相同的图像并使用反转图像的ColorMatrix .例如:

    protected override void OnPaint(PaintEventArgs e) {
        e.Graphics.DrawImage(mImage, Point.Empty);
        ImageAttributes ia = new ImageAttributes();
        ColorMatrix cm = new ColorMatrix();
        cm.Matrix00 = cm.Matrix11 = cm.Matrix22 = -0.99f;
        cm.Matrix40 = cm.Matrix41 = cm.Matrix42 = 0.99f;
        ia.SetColorMatrix(cm);
        var dest = new Rectangle(50, 50, 100, 100);
        e.Graphics.DrawImage(mImage, dest, dest.Left, dest.Top, 
            dest.Width, dest.Height, GraphicsUnit.Pixel, ia);
    }

其中mImage是我的样本1bpp图像,而我正在以50,50反转100x100矩形