AForge.Imaging.UnmanagedImage.Copy C# (CSharp) Method

        public void Copy( UnmanagedImage destImage )
        {
            if (
                ( width != destImage.width ) || ( height != destImage.height ) ||
                ( pixelFormat != destImage.pixelFormat ) )
            {
                throw new InvalidImagePropertiesException( "Destination image has different size or pixel format." );
            }

            if ( stride == destImage.stride )
            {
                // copy entire image
                AForge.SystemTools.CopyUnmanagedMemory( destImage.imageData, imageData, stride * height );
            }
            else
            {
                unsafe
                {
                    int dstStride = destImage.stride;
                    int copyLength = ( stride < dstStride ) ? stride : dstStride;

                    byte* src = (byte*) imageData.ToPointer( );
                    byte* dst = (byte*) destImage.imageData.ToPointer( );

                    // copy line by line
                    for ( int i = 0; i < height; i++ )
                    {
                        AForge.SystemTools.CopyUnmanagedMemory( dst, src, copyLength );

                        dst += dstStride;
                        src += stride;
                    }
                }
            }
        }

 public static void ConvertToGrayscale(UnmanagedImage source, UnmanagedImage destination)
 {
     if (source.PixelFormat != PixelFormat.Format8bppIndexed)
     {
         Grayscale.CommonAlgorithms.BT709.Apply(source, destination);
     }
     else
     {
         source.Copy(destination);
     }
 }