The program that you use for superimposition will do the scaling, translation and rotation. You do not need to scale those images prior to superimposition. You need the scale factor to estimate centroid size.

Dear Colleague ,

If you already scaled each foto using the "TPSDig" measure tools, you've already found the best way to scale size of photos; if you open the tps file with any .txt reader you will notice that the number corresponding to "Scale" change between individuals in cases like this.

But, as aforementioned, this step is important if interested in centroid size.

Thank you so much by all comments.

I am initiating my studies in morphogeo. I read the Zelditch' book about the theme (GeoMorph for Biologists, 2012) and now, with my data set, I am trying to apply some analysis. However, some procedures are not so clear in the help of packages from R or in forums about the theme.

But, I will following in the study. Thank you!

I hope that it will be clearer soon--we are now at the stage of proofreading the second edition of the Practical Companion to Geometric Morphometrics for Biologists: running analyses in freely available software. This new edition is almost entirely about doing analyses in R (the exceptions are that we also cover digitizing in tpsDig and using tpsUtil for various functions, like making the sliders file). The first edition predates geomorph, so it was past time for a new one. It is now much easier to do morphometric analyses in R, and I'd say that it's also much easier to do geometric morphometric analyses now that the software does not get in the way (and it does so much more than anything that we used to have)