c# - 将 8bpp 转换为 24bpp 时图像会移动

Question

当我使用以下代码将位图从 8bpp 转换为 24bpp 时，生成的图像发生了偏移，但我无法弄清楚原因，有人可以帮忙吗？

private static Bitmap ConvertTo24(Bitmap bmpIn)
{
    bmpIn.Save(@"F:\sara1.bmp");
    Bitmap converted = new Bitmap(bmpIn.Width, bmpIn.Height, PixelFormat.Format24bppRgb);
    using (Graphics g = Graphics.FromImage(converted))
    {
         // Prevent DPI conversion
         g.PageUnit = GraphicsUnit.Pixel;
         // Draw the image
         g.DrawImageUnscaled(bmpIn, 0, 0);
         // g.DrawImage(bmpIn, 0, 0);
    }
    converted.Save(@"F:\sara2.bmp");
}

---

Answer 1

以下代码对我有用:

private static Bitmap ConvertTo24(Bitmap bmpIn)
{
    bmpIn.Save(@"F:\sara1.bmp");
    Bitmap converted = new Bitmap(bmpIn.Width, bmpIn.Height, PixelFormat.Format24bppRgb);
    using (Graphics g = Graphics.FromImage(converted))
    {
        // Prevent DPI conversion
        g.PageUnit = GraphicsUnit.Pixel;
        // Draw the image
        // g.DrawImageUnscaled(bmpIn, 0, 0);
        g.DrawImage(bmpIn, 0, 0, converted.Width, converted.Height);
    }
    converted.Save(@"F:\sara2.bmp");
}

提供宽度和高度重新缩放图像。