Next: 3.2.5 Correcting within nip2 Up: 3.2 Infrared imaging Previous: 3.2.3 Correcting illumination Contents

##
3.2.4 Correcting with the command-line tool

First, close `nip2` and open a command line window, (xterm, mingw, etc). Move to the directory containing your image files with `cd`. For example, if you have made a directory called `raphael` inside your home directory, type:

> | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
> | `prompt% cd raphael` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

The program you need to use is called `light_correct`. You need to give it the name of the grey-card image and the names of all of the image files you want it to correct with that gray card. Suppose you have saved your gray card image as `grey.v`, and your painting image files are called `dat1.1.v` and `dat1.2.v`. You would then enter:

> | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
> | `prompt% light_correct grey.v dat1.1.v dat1.2.v` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

The program will run and print messages explaining its progress. It creates a new set of corrected image files, with the same names as before, but prefixed with `ic_`. In this example, it would create two new images files called `ic_dat1.1.v` and `ic_dat1.2.v`.

If there are a lot of image files to correct this could mean a lot of typing. Fortunately, you can use wildcard characters to abbreviate lists of file names. The example above can be abbreviated to:

> | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
> | `prompt% light_correct grey.v dat*.v` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

The `dat*.v` means `any filename which starts `dat` and ends with `.v`'.

You can use this technique to correct different parts of your mosaic with different grey cards. If you have a file called `grey1.v` for the first row in your mosaic, and a file called `grey2.v` for the second, you could do the correction in two parts:

> | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` | `` |  | `` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
> | `prompt% light_correct grey1.v dat1.*.v` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
> | `prompt% light_correct grey2.v dat2.*.v` |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

Next: 3.2.5 Correcting within nip2 Up: 3.2 Infrared imaging Previous: 3.2.3 Correcting illumination Contents