How to convert a bitmap to int[]?

Question

Hi there!

I'm writing a program to do some image processing on the GPU. For this I'm using CUDA.Net, but unfortunaly the CUDA doesn't recognize the type byte, in which I was able to store the pixels information using this code:

BitmapData bData = bmp.LockBits(new Rectangle(new Point(), bmp.Size),
                                ImageLockMode.ReadOnly,
                                PixelFormat.Format24bppRgb);

        // number of bytes in the bitmap
        byteCount = bData.Stride * (bmp.Height);


        byte[] bmpBytes = new byte[byteCount];


        Marshal.Copy(bData.Scan0, bmpBytes, 0, byteCount);

bmp.UnlockBits(bData);

return bmpBytes;

My problem resides in the fact that CUDA doesn't take this byte array, and if change it to a type int[] the program retrieves an AccessViolationException.

Does someone has any thoughts to resolve this problem?

Thanks in advance.

Answer 1

A bitmap is guaranteed to be a multiple of 4 bytes. So int[] will work:

  int[] bytes = new int[byteCount/4];
  Marshal.Copy(bData.Scan0, bytes, 0, byteCount/4);

That doesn't make it easy for the receiver though, I'd suggest you use PixelFormat.Format32bppRgb so one pixel is exactly the size of an int.