Another developer told me to use LockBits() for original bitmap, too. E.g., to convert a full screen bitmap (1280x960 Pixel) my pc works 65 seconds. Of course, I'll tell all users that you're the author of ConvertTo8bppFormat().įor this tool, there is one practical problem left: GetPixel() needs intolerable much time.

I call this feature a wonderful usable solution and shall copy it into my simple class FormPrint to print or save a form/control.

So first, we create a pointer to the required byte, and then by using the Marshal class, we can copy the color's index to the bitmap. In our case (8 bit per pixel), finding the appropriate information for a given pixel is very easy (row index * row length + column index). Some more explanations about the WriteBitmapData method: the BitmapData member Scan0 points to the first byte (physical memory that contains the pixel's information) and Stride contains the row size. Marshal.Copy( dataToCopy, 0, realByteAddr, Get unmanaged address of needed byte IntPtr realByteAddr = new IntPtr( 32(īyte dataToCopy = new byte / /// /// /// /// /// private static void WriteBitmapData( Return Math.Max( rDiff, Math.Max( bDiff, gDiff ) ) / /// /// /// private static byte GetMaxDiff(Color a, Color b) / /// /// /// private static byte GetSimilarColor(ColorPalette palette, Color color)įor( int i = 0 i /// Return similar color New Rectangle( 0, 0, image.Width, image.Height ),įor( int i = 0 i /// Returns Similar color / /// Source bitmap image /// public static Bitmap ConvertTo8bppFormat(Bitmap image)īitmapData bitmapData = destImage.LockBits( See the code below:Ĭopy Code /// /// Converts bitmap format to 8bpp Since it's impossible to work with Graphics because of the indexed color, we need to iterate all pixels in the source (rich color) bitmap image, get the pixel's color, and find a similar color from the Color palette (256 Colors) and save its index in the destination bitmap image (8bpp). So changing the color depth is a little bit tricky. I mean, it's possible to save a bitmap, but it's impossible to change the color depth by passing EncoderParameter. For some reason, the method Bitmap.Save doesn't really work for me. Now, we need to convert a rich color bitmap image to a bitmap with an 8bpp format. New Font( family, 12, FontStyle.Regular ),Ĭolor transColor = bitmap.GetPixel( 0, 0 ) Graphics g = Graphics.FromImage( bitmap )

/ Color to draw given character /// public static Bitmap Convert(Ĭhar charToDraw = encoding.GetChars( charCode ) / /// Charcter code /// ASCII, UNICODE.

Copy Code /// /// Converts TTF character to bitmap

Image to ttf