Question

unfortunately I cannot resort to C# in my current project, so I’ll have to solve this without the unsafe keyword.

I’ve got a bitmap, and I need to access the pixels and channel values directly. I’d like to go beyond Marshal.ReadByte() and Marshal.WriteByte() (and definitely beyond GetPixel and SetPixel).

Is there a way to put all the pixel data of the bitmap into a Byte array that works on both 32 and 64 bit systems? I want the exact same layout as the original bitmap, so the padding for each row (if it exists) also needs to be included.

Marshal doesn’t seem to have something akin to:

byte[] ReadBytes(IntPtr start, int offset, int count)

Unless I totally missed it…

Any help greatly appreciated,
David

ps. So far all my images are in 32BppPArgb pixelformat.

Answer 1

Marshal does have a Method that does exactly what you are asking. See Marshall.Copy()

public static void Copy(
    IntPtr source,
    byte[] destination,
    int startIndex,
    int length
   )

Copies data from an unmanaged memory
pointer to a managed 8-bit unsigned
integer array.

And there are overloads to go the other direction as well