Image Calibration and Astrophotography

One of the features needed in programs used in astrophotography is image calibration. It is an advanced image processing technique, which  also involves aligning and stacking images to make the final image clearer.

Definition of Image Calibration, Stacking and Aligning

Calibration means that certain signals are removed or corrected in order for the raw image to accurately represent the amount of light being emitted by the celestial body and captured by the camera. Stacking involves combining several images with short exposures into one master image to improve the contrast and color. This is done by using a number of mathematical formulas. Aligning involves lining up the images so that the bodies line up entirely.

Software Used in Image Calibration

There are a number of computer programs commonly used in astrophotography. However, only a handful of programs have the calibration feature. Software produced by camera manufacturers often includes some form of image processing but these can only be used with images taken during the daytime. These cannot be used in stacking, aligning or for calibration. For this purpose, more specialized software with a built in special astronomical image processing feature is necessary. Although Photoshop is capable of performing this function, the process becomes exhausting after several frames, and it is not as accurate as the astronomical image processing software.