Nikon Software Solution to 'Uncalibrated Colorspace'

Posted: Sun May 01, 2011 4:12 pm

For some time now I have been at wits end, and still am to some extent at the way Nikon/Nik software goes about manipulating EXIF data.

The problem has been:
After editing .NEF (RAW) image files in Capture NX 2 (and possibly Nikon View NX 2) and saving as a .JPG, results in some applications* reading the EXIF tag for colorspace as "Uncalibrated" or "Uncalibrated (sRGB)". *Such programs or web scripts are IMatch and Gallery 2, to name just a couple.

The importance of using the sRGB colorspace is so that color aware applications can properly display images as they are meant to be seen. Also important is that scripts that read the EXIF tags can present meaningful and correct data. If the tag is improperly formatted or the wrong colorspace/no color space is used an application may have no way to determine what the intended colorspace ought to be.

The bottom line is this; there are standards and the companies do not always follow them. They generally rely on things like "interpretation". Which means that at times they "cherry pick" the standards leaving out things they do not feel are important or that may present a financial barrier (cost to implement/correct).

The Solution to Nikon software incorrectly tagging the EXIF Colorspace Tag is as follows:

When saving as a .JPG or .TIF format, a Save Options Dialog box will appear such as this one for .JPG:

Or this one for .TIF:

Simply uncheck the option to Embed ICC profile. The profile will still be used, and the EXIF Colorspace tag will now be correctly written so that other applications and scripts can read the data.

The method that Nikon/Nik Software uses to embed the ICC Profile within the EXIF data structure, prevents applications and scripts from reading the data.

Sources, Resources and Information:

EXIF 2.2 - Specification by JEITA, April 2002.

4.6.5 Exif IFD Attribute Information (Page 32)

Quote:

B. Tag Relating to Color Space
ColorSpace
The color space information tag (ColorSpace) is always recorded as the color space specifier.
Normally sRGB (=1) is used to define the color space based on the PC monitor conditions and environment. If a
color space other than sRGB is used, Uncalibrated (=FFFF.H) is set. Image data recorded as Uncalibrated can be
treated as sRGB when it is converted to Flashpix. On sRGB see Annex E.

Tag = 40961 (A001.H)
Type = SHORT
Count = 1
1 = sRGB
FFFF.H = Uncalibrated
Other = reserved

Source: http://www.exif.org/specifications.html