C# 将byte[]转化为灰度图片

想要将存在byte[]信号强度数据转换成灰度图片，现在用下面这种方法，总是出现内存操作
错误，请大牛来为我解惑~~不胜感谢！
public static Bitmap ToGrayBitmap(Int16[] rawValues, int width, int height)
{
//// 申请目标位图的变量，并将其内存区域锁定
Bitmap bmp = new Bitmap(width, height,PixelFormat.Format16bppRgb565);
Rectangle newbmp = new Rectangle(0, 0, width, height);
BitmapData bmpData = bmp.LockBits((newbmp),ImageLockMode.WriteOnly, PixelFormat.Format16bppRgb565);
//// 获取图像参数
int stride = bmpData.Stride; // 扫描线的宽度
int offset = stride - width; // 显示宽度与扫描线宽度的间隙

int scanBytes = stride * height; // 用stride宽度，表示这是内存区域的大小
IntPtr iptr = bmpData.Scan0; // 获取bmpData的内存起始位置

    //// 下面把原始的显示大小字节数组转换为内存中实际存放的字节数组
    int posScan = 0, posReal = 0;// 分别设置两个位置指针，指向源数组和目标数组

    Int16[] pixelValues = new Int16[scanBytes]; //为目标数组分配内存

    for (int x = 0; x < height; x++)
    {
        //// 下面的循环节是模拟行扫描
        for (int y = 0; y < width; y++)
        {
            pixelValues[posScan++] = rawValues[posReal++];
        }
        posScan += offset; //行扫描结束，要将目标位置指针移过那段“间隙”
    }
    //// 用Marshal的Copy方法，将刚才得到的内存字节数组复制到BitmapData中  
    Marshal.Copy(pixelValues, 0, iptr, scanBytes);
    bmp.UnlockBits(bmpData);       
    return bmp;
}

BitmapData.stride 是字节数，你怎么用在 Int16 的计数上了？
牛头不对马嘴！

   private static Bitmap PGray(Bitmap src)
    {
        int w = src.Width;
        int h = src.Height;

    //构建与原图像大小一样的模版图像
        Bitmap dstBitmap = new Bitmap(src.Width, src.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);

   //将原图像存入内存
        System.Drawing.Imaging.BitmapData srcData = src.LockBits(new Rectangle(0, 0, w, h), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
        System.Drawing.Imaging.BitmapData dstData = dstBitmap.LockBits(new Rectangle(0, 0, w, h), System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
        unsafe
        {
            byte* pIn = (byte*)srcData.Scan0.ToPointer();
            byte* pOut = (byte*)dstData.Scan0.ToPointer();
            byte* p;
            int stride = srcData.Stride;
            int r, g, b;
            for (int y = 0; y < h; y++)
            {
                for (int x = 0; x < w; x++)
                {
                    p = pIn;
                    r = p[2];
                    g = p[1];
                    b = p[0];

       //调用图像灰度化公式

                    pOut[0] = pOut[1] = pOut[2] = (byte)(b * 0.114 + g * 0.587 + r * 0.299);   
                    pIn += 3;
                    pOut += 3;
                }
                pIn += srcData.Stride - w * 3;
                pOut += srcData.Stride - w * 3;
            }
            src.UnlockBits(srcData);
            dstBitmap.UnlockBits(dstData);
            return dstBitmap;
        }

    }

直接使用！