A 16 x 16 image of 8 bits deep requires a total of 128 bits.
If you have 256 slots (pixels) in which to embed these 128 bits, then by the pigeon hole principle, the answer is Yes, it can be done, averaging 1 embedded bit for every 2 original pixels.
If the 16 x 16 image to be embedded is 16 bits deep, then still, Yes, that could be done, at an averaging of 1 embedded bit for every original pixel.
Thus, the answer to your question would appear to be Yes -- provided you do not have any additional restrictions you have not previously mentioned.
