Image processing in astronomy

[hishadow]

Is anyone here familiar with image processing and common data formats used in astronomy. I've been working on a small program and wanted to see if it could be useful for some simple image processing in relation to astronomy. I'm not familiar with what formats are used, like what kind of contrast resolution is used etc. Any pointers to freely available test data would also be appreciated.

[Chris Peterson]

Is anyone here familiar with image processing and common data formats used in astronomy. I've been working on a small program and wanted to see if it could be useful for some simple image processing in relation to astronomy. I'm not familiar with what formats are used, like what kind of contrast resolution is used etc. Any pointers to freely available test data would also be appreciated.

Virtually all astronomical images use a format called FITS, which you can read about here. You can freely download libraries to handle reading and writing FITS data. If you are writing your own processing routines, I would highly recommend taking advantage of one of these libraries, since they are well tested and will save you a lot of effort. Bear in mind that astronomical images are usually made up of more bits per channel than most conventional images. Normally, you need to be able to handle at least 16-bit integer data, and 32-bit integer or IEEE float data is quite common. Standards are loose with respect to how color data is stored. Although it is possible to store multiple planes in a single FITS file, it is more common with color (or narrowband filters) to save each channel in a separate file.

"Contrast" is meaningless in terms of astronomical data; it only becomes useful during the display process. Resolution has different meanings. Usually it refers to the spatial resolution of an image: arcseconds per pixel. That is different from the image size (or number of pixels), which isn't the same as "resolution", although it is often used that way in conventional digital photography.

FITS Liberator is a free plugin for Photoshop that allows reading FITS files. Check out their site for more information, and for sample files you can work with.

[hishadow]

Thank you for lots of useful information I can start working from.