How to detect the color of a pixel on the monitor in C#?

Question

I need to detect the color of a pixel on my monitor. How do I retrieve it on coordinate (x,y) in C#?

duplicate, see:http://stackoverflow.com/questions/1483928/how-to-read-the-color-of-a-screen-pixel — Bolu, Nov 17 '10 at 11:58

score 5 · Answer 1 · answered Nov 17 '10 at 11:58

5

Use Graphics.CopyFromScreen to copy a 1x1 bitmap, Bitmap.GetPixel() to get its color.

answered Nov 17 '10 at 11:58

Hans Passant

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Thank you. That seems like an easy solution. – Kasper Hansen Nov 17 '10 at 12:05

score 2 · Answer 2 · answered Nov 17 '10 at 12:17

First Import these Dlls

    [DllImport("user32.dll")]    
    static extern IntPtr GetDC(IntPtr hwnd);

    [DllImport("user32.dll")]
    static extern Int32 ReleaseDC(IntPtr hwnd, IntPtr hdc);

    [DllImport("gdi32.dll")]
    static extern uint GetPixel(IntPtr hdc, int nXPos, int nYPos);

Then write this method GetPixelColor(x,y);

      static public System.Drawing.Color GetPixelColor(int x, int y)
      {
       IntPtr hdc = GetDC(IntPtr.Zero);
       uint pixel = GetPixel(hdc, x, y);
       ReleaseDC(IntPtr.Zero, hdc);
       Color color = Color.FromArgb((int)(pixel & 0x000000FF),
                    (int)(pixel & 0x0000FF00) >> 8,
                    (int)(pixel & 0x00FF0000) >> 16);
       return color;
      }

Call the method Color clr= GetPixelcolor(50,50);

score 1 · Answer 3 · edited May 23 '17 at 11:47

1

First, capture the screen.

Rectangle screenRegion = Screen.AllScreens[0].Bounds;
Bitmap screen = new Bitmap(screenRegion.Width, screenRegion.Height, PixelFormat.Format32bppArgb);

Graphics screenGraphics = Graphics.FromImage(screenBitmap);
screenGraphics.CopyFromScreen(screenRegion.Left, screenRegion.Top, 0, 0, screenRegion.Size);

Then, get the pixel from the bitmap.

edited May 23 '17 at 11:47

Community

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answered Nov 17 '10 at 12:00

Arseni Mourzenko

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Note that it works only with the primary monitor. If you need to capture a pixel from other monitors, you have to change the zero index at the first line of the code. – Arseni Mourzenko Nov 17 '10 at 12:03

score 0 · Answer 4 · edited Aug 19 '12 at 05:41

0

You can use winapi GetPixel(...)

edited Aug 19 '12 at 05:41

Servy

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answered Nov 17 '10 at 11:57

pyCoder

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How to detect the color of a pixel on the monitor in C#?

4 Answers4