Pixel adjustment

[peter.hansen@epfl.ch]

Hello

New user hoping to learn some tricks.
I would like to adjust pixel-values of .JPG's by applying a equation to the images.
Basically I would like to correct for pixel-value drop-off in fisheye image (correct for vignetting).
The images are to be merged with hdrgen afterwards into luminance maps - but I would like to correct for vignetting.

Can I use Imagemagick for this?
And how should I do it?

Hope to hear from you all

Kind regards
Peter

[snibgo]

Yes, IM can do this.

The easy but slow method is to use "-fx". See http://www.imagemagick.org/script/fx.php

If you have lots of images, the same size and needing the same adjustment, you can create a mask image that is composited with each of the inputs in turn for the required adjustment. This is more difficult initially, but is then much faster per image.

[fmw42]

In the future when asking questions about Imagemagick, if you start using it, please see the following:

Please, always provide your IM version and platform when asking questions, since syntax may differ. Also provide your exact command line and if possible your images.

See the top-most post in this forum "IMPORTANT: Please Read This FIRST Before Posting" at viewtopic.php?f=1&t=9620

For novices, see

viewtopic.php?f=1&t=9620
http://http://www.imagemagick.org/scrip ... essing.php
http://www.imagemagick.org/Usage/reference.html
http://www.imagemagick.org/Usage/