Png32ToPna.cs

public static void Png32ToPna(Bitmap image)
{
	BitmapData data = image.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.ReadWrite, image.PixelFormat);
	try
	{
		unsafe
		{
			byte* ptr = (byte*)data.Scan0;

			for (int i = 0; i < data.Height; i++)
			{
				for (int j = 0; j < data.Width; j++)
				{
					ptr[1] = ptr[2] = ptr[3] = ptr[0];
					ptr += 3;
				}

				ptr += data.Stride - data.Width * 4;
			}
		}
	}
	finally
	{
		image.UnlockBits(data);
	}
}