Many thanks for the file. I have just downloaded it and will give it a whirl!
Yes, that kind of interpolation is what I am talking about. I will certainly agree that it makes images ‘prettier’ but I don’t think it is a scientifically valid procedure, particularly if no details are given on how the image was processed.
In the extreme case, imagine you have a 3×3 pixel Maldi ion image. The central pixel produced no signal for a particular ion mass (and so is coloured black), yet all the surrounding pixels registered a strong signal (and so are coloured white). If I were to now smooth/interpolate this image the central pixel will be transformed into a shade of gray suggesting that some signal was obtained from this position.
Perhaps in 90% of cases the ion of interest really was present and for some reason wasn’t successfully detected and so smoothing makes the image appear a little more like it ‘should’. But what about the 10% of cases where the ion of interest really wasn’t present? It seems to me that this is exactly the sort of information that you are trying to determine with imaging and by smoothing images you are manipulating your data and potentially losing this information.
I appreciate my example is a little extreme, but this doesn’t make the point any less valid. Although I will happily be proved wrong. 😀