That's not unlike what you might do to recover a high frequency signal by using a band-pass filter and then sampling that (which is typically done by a mixer in a traditional analog system). If you know what the alias is you can reconstruct your signal. The point though is that you can't sample signals of a higher bandwidth without aliasing. If you know in advance the only alias is at a given frequency then you don't need to filter. The purpose of the filter is to ensure that the bandwidth of the sampled signal is correct given that you know nothing about the frequency content of the original signal. The sampling theorem is pretty specific and its proof is solid. So while it might be true you could use a single pixel to tell the difference between an apple and a banana, without filtering the image before sampling, it doesn't really relate to the sampling theorem at that point.