For years I have scanned negatives using vuescan, and then opened the resulting tiff file in gimp without incident. But now something strange has started happening. I scanned a b/w negative, and when I opened it, it came up in ufraw and I had to fiddle with it in order to get it into gimp. It wwas an noying and took a lot of time, and the image was not the same as it appeared in Vuescan, which previously was always the case. I don't understand why gimp is doing that.

I've checked my gimp setup and don't see any place where such operation has been specified. Can anyone explain what is happening and how I should stop it?

There are also some other peculiarities. When ufraw comes up, it says it can't find a profile for the display---which is an old one no longer valid, but there doesn't seem to be any way to change the setting for the profile. Using Options, I can delete it, but i can't set a different one.

I am running gimp 2.6.6 under Fedora 9 Linux.

On Sat, 2009-09-12 at 22:50 +0200, Sven Neumann wrote:

On Fri, 2009-09-11 at 17:17 -0500, Leonard Evens wrote:

For years I have scanned negatives using vuescan, and then opened the resulting tiff file in gimp without incident. But now something strange has started happening. I scanned a b/w negative, and when I opened it, it came up in ufraw and I had to fiddle with it in order to get it into gimp. It wwas an noying and took a lot of time, and the image was not the same as it appeared in Vuescan, which previously was always the case. I don't understand why gimp is doing that.

Sounds like ufraw has installed itself as a loader for TIFF images. To verify that you could look at your ~/.gimp-2.6/pluginrc and search for "tiff". You could even edit that file to remove the registration of the ufraw procedure for TIFF images.

I thought something like that was the problem. Thanks for helping me find where to look. But there is still one thing I don't understand. The problem doesn't happen with all tiff files, just with those created by vuescan from a film scan. It doesn't have for example with a tiff file created from a flatbed scan. So ufraw is somehow identifying these tiff files as coming from a caera, which indirectly is true.

Sven

I am starting to do raw images with my Nikon D90. I have ufraw both as a gimp plugin and a standalone program under Fedora Linux 14. I have started to look at the ufraw User's Guide at the ufraw website, but it would be helpful to have some tutorials or other guides if they exist.

I already found that ufraw doesn't correct for lens distortion adequately. According the the ufraw forum at sourceforge, this is a known problem.

I can do the lens correction with ufraw manually, but there are three parameters, and it is hard to figure out how to adjust them visually. The gimplensfun filter for gimp does a much better job. It reads the lens data from the exif information in the image, and makes the correction based on the lensfun database. ufraw is supposed to do something like that, but it gets it wrong.