| .TH LIGHT_CORRECT 1 "14 Oct 1996" |
| .SH NAME |
| light_correct \- correct illumination errors on set of images |
| .SH SYNOPSIS |
| .B light_correct grey image1 image2 image3 ... |
| .SH DESCRIPTION |
| The first argument should be an image of a piece of grey card, subsequent |
| arguments should be images taken with the same lighting set-up which need |
| correcting. The corrected images are written to files prefixed with "ic_". |
| |
| For example, suppose you have a directory with the following files in: |
| |
| example% ls |
| dat1.1.v dat1.2.v dat2.1.v dat2.2.v dat3.1.v dat3.2.v |
| dat4.1.v dat4.2.v grey.v |
| |
| then run light_correct like this: |
| |
| example% light_correct grey.v dat*.v |
| |
| to generate this: |
| |
| example% ls |
| dat1.1.v dat1.2.v dat2.1.v dat2.2.v dat3.1.v dat3.2.v |
| dat4.1.v dat4.2.v grey.v |
| ic_dat1.1.v ic_dat1.2.v ic_dat2.1.v ic_dat2.2.v ic_dat3.1.v |
| ic_dat3.2.v ic_dat4.1.v ic_dat4.2.v |
| |
| light_correct works by smoothing out the grey card image, finding |
| grey-mean/pixel for each point, and then multiplying the result by all the |
| following images. It also removes any .desc files it generates, to avoid |
| problems with im_global_balance(3). |
| |
| .SH RETURN VALUE |
| returns 0 on success and non-zero on error. |
| .SH SEE ALSO |
| header(1), vips(1) |
| .SH COPYRIGHT |
| The National Gallery and Birkbeck College, 1989-1996. |
