Abstract

There is no universally accepted way to measure a galaxy's brightness; all of the methods that I know of have their drawbacks. I shall discuss measuring galaxies' fluxes by fitting simple models, and outline some tricks that make this efficient enough to be used for the routine processing of hundreds of millions of objects.



I shall then introduce a new algorithm for deblending overlapping images, and discuss its application to bright nearby galaxies in the NGC catalogue.



Finally, I shall lay down the law on the correct way to present colour pictures of astronomical images.