c# - Can you change one colour to another in an Bitmap image? -

for bitmap, there maketransparent method, there 1 similar changing 1 color another?

// sets color.white transparent bitmap mybitmap = new bitmap(sr.stream); mybitmap.maketransparent(system.drawing.color.white); 

is there can this?

bitmap mybitmap = new bitmap(sr.stream); mybitmap.changecolor(system.drawing.color.black, system.drawing.color.gray); 

through curiosity yorye nathan's comment, extension created modifying http://msdn.microsoft.com/en-gb/library/ms229672(v=vs.90).aspx.

it can turn pixels in bitmap 1 colour another.

public static class bitmapext {     public static void changecolour(this bitmap bmp, byte incolourr, byte incolourg, byte incolourb, byte outcolourr, byte outcolourg, byte outcolourb)     {         // specify pixel format.         pixelformat pxf = pixelformat.format24bpprgb;          // lock bitmap's bits.         rectangle rect = new rectangle(0, 0, bmp.width, bmp.height);         bitmapdata bmpdata =         bmp.lockbits(rect, imagelockmode.readwrite,                      pxf);          // address of first line.         intptr ptr = bmpdata.scan0;          // declare array hold bytes of bitmap.          // int numbytes = bmp.width * bmp.height * 3;          int numbytes = bmpdata.stride * bmp.height;         byte[] rgbvalues = new byte[numbytes];          // copy rgb values array.         marshal.copy(ptr, rgbvalues, 0, numbytes);          // manipulate bitmap         (int counter = 0; counter < rgbvalues.length; counter += 3)         {             if (rgbvalues[counter] == incolourr &&                 rgbvalues[counter + 1] == incolourg &&                 rgbvalues[counter + 2] == incolourb)               {                 rgbvalues[counter] = outcolourr;                 rgbvalues[counter + 1] = outcolourg;                 rgbvalues[counter + 2] = outcolourb;              }         }          // copy rgb values bitmap         marshal.copy(rgbvalues, 0, ptr, numbytes);          // unlock bits.         bmp.unlockbits(bmpdata);     } } 

called bmp.changecolour(0,128,0,0,0,0);