What corr_im_fast Does

This is a short description of the steps that corr_im_fast takes. Further details can be gleaned from the perl script itself.

1. corr_im_fast is provided with directories for image and calibration files. For more information on the command line, see Section 8.2.1.

2. It scans the calibration directory for the best dark image. This image must have the same exposure time as the data image, the date must be on or before the data image, and the camera temperature must be within 2${^\circ}$ of the data image.

   If a proper dark is not found, the program will exit with an error.

3. It scans the calibration directory for the best flat image. This image must have been taken with data on or before the date of the data image.

   If a proper flat is not found, the program will exit with an error.

4. It checks which amplifier (or both) was used with the image to determine the proper image cropping parameters. The cropping removes the bias areas and leaves only image data.

5. It runs new_dfc.