Question

well, i wonder if one writes code to show a bitmap on a form.
Would it be possible to access it directly like an array in c#?

I am wondering this because the bitmap is already there in memory and on screen.
But I’m not sure on how to point to it; like it where a pointer or array so, I want to do this in c# and I also don’t know the array data structure on the form (like is it RGB BGR / RGB24 etc)

As a note, this image source isn’t from a file, it’s from a webcam.
Also, a reason I want to do this is because getpixel / putpixel is to slow for what I want.

Answer 1

If you want to get the image pixels in the array you can do it like this:

            Bitmap image = new Bitmap("somebitmap.png");
            Rectangle area = new Rectangle(0,0,image.Width, image.Height);
            BitmapData bitmapData = image.LockBits(area, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
            int stride = bitmapData.Stride;
            IntPtr ptr = bitmapData.Scan0;
            int numBytes = bitmapData.Stride * image.Height;
            byte[] rgbValues = new byte[numBytes];
            Marshal.Copy(ptr, rgbValues, 0, numBytes);

And when you change them you should copy that array back to the Bitmap using this:

            Marshal.Copy(rgbValues, 0, bitmapData.Scan0, bitmapData.Stride * image.Height);
            image.UnlockBits(bitmapData);

But if you realy want to deal with pixels like you said, you should use some FastBitmap implementation. There are many other implementations available also.