Is there a way to get the galsim stamp size of a profile without computing the pixel table?

Question

In galsim, I have created a galaxy with a given sersic profile. I convole it by a PSF. I would like to know if there is a way to get the size of the stamp that would be computed using drawImage without actually computing the pixels. Basically, I'd like to know how big would be my image with a 0.05 folding_threshold, with a 0.01 or with a 0.005.

Answer 1

Yes, there is a way to do this. The drawImage method has a keyword argument setup_only, for which the default is False. If you call drawImage with setup_only=True, then it will return an empty image of the size you would get after drawing (but without actually computing the pixel values).

You can read about this and other drawImage options in the docstring for drawImage.