问题
I'm using WinForms. I have a picture-box in my form. When I open a picture in the picture-box I am able to invert the colors back and forth on a click of a button, but my code is extremely slow. How can I increase the performance.
private void Button1_Click(object sender, System.EventArgs e)
{
Bitmap pic = new Bitmap(PictureBox1.Image);
for (int y = 0; (y
<= (pic.Height - 1)); y++) {
for (int x = 0; (x
<= (pic.Width - 1)); x++) {
Color inv = pic.GetPixel(x, y);
inv = Color.FromArgb(255, (255 - inv.R), (255 - inv.G), (255 - inv.B));
pic.SetPixel(x, y, inv);
PictureBox1.Image = pic;
}
}
}
回答1:
You are setting the control's picture each time you change a pixel, which causes the control to redraw itself. Wait until you've finished the image:
Bitmap pic = new Bitmap(PictureBox1.Image);
for (int y = 0; (y <= (pic.Height - 1)); y++) {
for (int x = 0; (x <= (pic.Width - 1)); x++) {
Color inv = pic.GetPixel(x, y);
inv = Color.FromArgb(255, (255 - inv.R), (255 - inv.G), (255 - inv.B));
pic.SetPixel(x, y, inv);
}
}
PictureBox1.Image = pic;
回答2:
It`s work for me...
private Image InvertingImage(Image source)
{
//create a blank bitmap the same size as original
Bitmap newBitmap = new Bitmap(source.Width, source.Height);
//get a graphics object from the new image
Graphics g = Graphics.FromImage(newBitmap);
// create the negative color matrix
ColorMatrix colorMatrix = new ColorMatrix(new float[][]
{
new float[] {-1, 0, 0, 0, 0},
new float[] {0, -1, 0, 0, 0},
new float[] {0, 0, -1, 0, 0},
new float[] {0, 0, 0, 1, 0},
new float[] {1, 1, 1, 0, 1}
});
// create some image attributes
ImageAttributes attributes = new ImageAttributes();
attributes.SetColorMatrix(colorMatrix);
g.DrawImage(source, new Rectangle(0, 0, source.Width, source.Height),
0, 0, source.Width, source.Height, GraphicsUnit.Pixel, attributes);
//dispose the Graphics object
g.Dispose();
return newBitmap;
}
来源:https://stackoverflow.com/questions/33024881/invert-image-faster-in-c-sharp