bmi.bmiHeader.biSizeImage = w * h * 4;
PointerByReference ppbits = new PointerByReference();
hBitmap = gdi.CreateDIBSection(memDC, bmi,
GDI32.DIB_RGB_COLORS,
ppbits, null, 0);
oldBitmap = gdi.SelectObject(memDC, hBitmap);
Pointer pbits = ppbits.getValue();
Raster raster = buf.getData();
int[] pixel = new int[4];
int[] bits = new int[w * h];
for (int row = 0; row < h; row++) {