Lockbits with ushort greyscale values

Question

I want to create a bitmap from given 16 bit greyscale values. So far I have this code:

var value = CamData.ToArray();

        var b = new Bitmap(160, 112, PixelFormat.Format24bppRgb);
        var bdata = b.LockBits(new Rectangle(0, 0, 160, 112), ImageLockMode.WriteOnly, b.PixelFormat);

        unsafe
        {
            fixed (ushort* pData = &value[0])
            {
                Marshal.Copy((IntPtr)pData, new IntPtr[]{ bdata.Scan0}, 0, value.Length);
            }
        }
        b.UnlockBits(bdata);

but I get an error in the Marshal.Copy Methode: "The requested range is beyond the end of the array". Where is the error?

thanks

score 1 · Answer 1 · answered Mar 29 '11 at 08:26

1

You cannot copy to a memory area defined by a pointer: you need to pass real array not a pointer to an array. You are passing an array of size 1 IntPtr and that will not work.

answered Mar 29 '11 at 08:26

Aliostad

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score 0 · Answer 2 · answered Mar 29 '11 at 08:37

0

bdata.Scan0 is an IntPtr that points to the beginning of the locked memory area. You shouldn't wrap it in an array. And you can use Marshal.Copy with an array as the source. So your code could be:

Marshal.Copy(value, 0, bdata.Scan0, value.Length);

This will use this overload of Marshal.Copy.

answered Mar 29 '11 at 08:37

driis

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okay thanks, but now I get the error that I'm trying to write into protected storege?! – h0ppel Mar 29 '11 at 08:57
Because, you were actually trying to write into an array of Intptr with Length 1, and your data is probably longer than 1 (or 2). – driis Mar 29 '11 at 09:33

Lockbits with ushort greyscale values

2 Answers2