Inverting bitmap

[Jhd.Honza]

Which method allows me to invert a bitmap object?



(Well, actually it will be sufficient to specify background color in bitmap constructor, if it is possible...)

[DevGrp]

Look in System.Drawing Namespace.

[hellswraith]

Here is some code I wrote to change a picture in a PictureBox around:

private void RotateRight()
{
//Code here rotates the picture right
Bitmap pic = new Bitmap(pbViewArea.Image);
pic.RotateFlip(System.Drawing.RotateFlipType.Rotate90FlipNone);
pbViewArea.Image = pic;
}

private void RotateLeft()
{
//Code here rotates the picture left
Bitmap pic = new Bitmap(pbViewArea.Image);
pic.RotateFlip(System.Drawing.RotateFlipType.Rotate270FlipNone);
pbViewArea.Image = pic;
}
		
private void FlipHorizontal()
{
//Code here flips the picture horizontally
Bitmap pic = new Bitmap(pbViewArea.Image);
pic.RotateFlip(System.Drawing.RotateFlipType.RotateNoneFlipX);
pbViewArea.Image = pic;
}

private void FlipVertical()
{
//Code here flips the picture vertically
Bitmap pic = new Bitmap(pbViewArea.Image);
pic.RotateFlip(System.Drawing.RotateFlipType.RotateNoneFlipY);
pbViewArea.Image = pic;
}

[Jhd.Honza]

Well, thank you for reply; but I was thinking about color inverting - eg. changing black into white.

[sunburnt]

I just wrote this -- I think it works?

        private void button1_Click(object sender, System.EventArgs e)
        {

            Bitmap m = new Bitmap(pb1.Image);
            Int32 ax = 0; Int32 ay = 0;
            Color c = new Color();
            int r,g , b ;
            for (ax = 0; ax < m.Width; ax++)
            {
                for (ay = 0; ay < m.Height; ay++)
                {
                    c = m.GetPixel(ax, ay);
                    r = Math.Abs(c.R - 255);
                    g = Math.Abs(c.G - 255);
                    b = Math.Abs(c.B - 255);
                    m.SetPixel(ax, ay, Color.FromArgb(r,g,b));
                }
            }

            pb1.Image = m;
        } 

There's probably a faster way to do this :P