Color management observations

[Winfried]

I made two observations:
- the tumbnails are not color managed (normally no problem)
- the Exif-flag regarding the the color space is not honoured, i.e. if I set my camera to sRGB and shot JPGs PWP8 does not recognsises this.
Same with Adobe RGB. JPG from camera normally don't contain an icc-profile, but just set the exif-flag.

[jsachs]

There is code in PWP 8 to infer the color space from the EXIF data, although the standard is vague with regards to AdobeRGB. Can you email me a sample JPEG file so I can check the EXIF tags?

[jsachs]

Apparently, the Microsoft GDI+ code PWP8 uses to read JPEG files inserts an "opRGB" profile in the image. The LeadTools JPEG reader used by PWP7 did not do this. opRGB is a so-called "optional" profile which has the same properties as AdobeRGB (the official version of which is copyrighted).

If there is no profile, PWP 8 does look at the EXIF data and infers sRGB or AdobeRGB and inserts these profiles into the file automatically. This is what happens when reading TIFF files generated by a RAW converter, for example. Unfortunately since opRGB does not exactly match AdobeRGB byte-for-byte, PWP8 performs an unnecessary conversion from one to the other when reading jpeg files.

[jsachs]

I fixed this problem for the next release by detecting opRGB and, if found, replacing it with AdobeRGB.

[jsachs]

Thumbnails are now color managed for the next (20-Apr) release.