Copy RAW photo to Allocation

Question

To achieve photo stacking I have been creating Bitmap from ImageReader decoded bytes and copy into Allocation using Allocation.copyFrom(Bitmap bitmap). But Bitmap use 8 bit on color (max value 255). I want tu use Raw Data (16 bit on color). How to copy result bytes (in 16bit on pixel format) to Allocation? Render script should use ushort4 to store pixel.