Floyd L. Davidson
jeff@cjsa.com (Jeffery Small) wrote:

Jeffery Small
I thought I would post this to the digital group to see if there were any Minolta or Sony users who used the UFRaw converter software with their raw image files. I have been having serious problems and wanted to see if this was observed by others. Here is my story.

Ubuntu 13.10 system running on an Asus U56E system UFRaw ver. 0.19.2 Dcraw ver. 9.19.1 GIMP ver. 2.8.6 Darktable ver. 1.2.3 Shotwell ver. 0.15.0

When attempting to load Minolta (mrw) and Sony (arw) raw image files into GIMP, the UFRaw plug-in is not properly processing them. The following webpage has images which demonstrate the problem:

http://smallthoughts.com/photos/misc/GIMP/index.html

The raw files are being imported with distorted color, exposure and contrast. However, as the additional images show, other programs such as Darktable and Shotwell and the Minolta/Sony editing programs (on Windows) are importing and displaying these raw files properly.

Has anyone else been experiencing similar problems with their raw files of any type?

Floyd L. Davidson
Typically UFRAW is configured to save the current configuration as the default for the next image, which means (with that option enabled) you must set all configuration options each time UFRAW is started. Or another way to put it, there is no standard set of defaults that will always be somewhere close. If the last image processed was way out in left field, the next one will not even come close to looking right unless it is also off into left field.

With the screen shots you are showing we can't tell anything other than what "exposure" is set for. There are two places where a gamma curve can be set, plus slider options for gamma value and gamma linearity. (If it is compiled in, you may also have a slider option for "contrast".) Any of those, with odd defaults, might be the cause of the way the RGB image is being produced.

There are a number of ways, if you need a standard default configuration, to accomplish that.

You could configure UFRAW to have one preset default configuration used for every image. Sounds good, but in practice that will cost a huge amount of processing time unless you actually do RAW conversions one at a time (for example using UFRAW as a plugin to GIMP to preprocess individual images).

The most efficient workflow is usually invoking UFRAW interactively on a directory full of RAW files, and writing only the "ID" file for each while using it interactively. When finished with all of the RAW files UFRAW is then invoked as a batch process to produce the RGB output files (while you can then take a coffee break or whatever).

At the beginning of the interactive session every configuration option is set as desired, and the configuration for each image is the default for the next.

-- Floyd L. Davidson http://www.apaflo.com/ Ukpeagvik (Barrow, Alaska) floyd@apaflo.com