Can I ask you something? What is a good colorspace for comparing stars and galaxies in your opinion? What is a good colorspace for processing astronomical images in general?

But aren't E0 type galaxies spherical?

Thanks, but is there a database out there which gives me an image and tells me "there are X galaxies in here". I found galaxyzoo but I really dont see any image files in their data release

ned.ipac.caltech.edu/cgi-bin/…

Also someone suggested I could use the NED Database for getting a count of the galaxies in the image, but I cannot seem to use it at all

Dumb question but can I estimate the PSF of a camera from an image??

Can you tell me how I could use the queries? Say I want an image of a region with only the count of ALL galaxies in that region, then save that image without any labels

I get this when trying to do a search ned.ipac.caltech.edu/cgi-bin/…

Please tell me how to use the NED, I cannot get it to give me the images!

Say I just want to do stars-galaxy separation, the galaxy can be of any type. Check my update for a sample image, can you elaborate " Stars are not spatially extended, which is perhaps the main way of separating stars and galaxies on an image"

Do you have any idea how I could use image processing to classify different kinds of galaxies? I know that for elliptical galaxies, I can directly estimate the parameters of the best fit ellipse (to the contour) and get the eccentricity, thresholding on its value can give me a rough E0 - E5 scale. What about the other kinds? Also Do you know how to differentiate between stars and galaxies, given only image data? Not any other sensor/header data, but only image data?