ProPhoto RGB and PTGui panorama problem?

[earlybird]

Hi,
 I am using a trial version of PTGui to stitch panoramas and have noticed that when I supply it with .tif files using the ProPhoto RGB color space the .tif file output from PTGui does not seem to have the ProPhoto RGB color space recognized by some applications. At the same time, the ProPhoto RGB colorspace is honored by other applications.

 Specifically, my old Windows 7 Photo Viewer recognizes the ProPhoto RGB colorspace on the individual source files but not on the panorama that PTGui stitched. The same panoramas stitched in PTGui open fine in my Photoshop CS6 install.

 I enjoy using Photo Viewer to open and view flattened .tif files quickly. When I finish editing a multilayer .psd or .psb I make a master .tif file to use as the reference and source for jpeg and print output. 

  This issue with the panoramas persists even when the panorama is used as the basis for a multilayer Photoshop file that receives further editing. A new flattened .tif file made via save has the same issue: the Photo Viewer does not recognize the ProPhoto RGB colorspace. I am perplexed that whatever issue occurs persists after throughput in Photoshop.

 I found a workaround solution. If I copy and paste the contents of the .tif panorama produced by PTGui into a New Photoshop project, I can then save the copy of the panorama as a .tif file that Photo Viewer recognizes as being in a ProPhotoRGB colorspace.



 I used a tool named ExifToolGUI to view the colorspace info in all the files and they are all listed as ProPhoto RGB.

 I opened each of the .tif image files in Notepad++ and looked at the xmpmeta info. The content and formatting differed between the source files and the PTGui panorama file, but when I found each file's colorspace line, it said "ProPhoto RGB."

 I am guessing that Windows Photo Viewer is looking for some other info, which is in the metadata of the source files but is not in the PTGui panorama file.

 I made a small test with 3 source files and a panorama that I can upload if it is helpful.

 Any ideas? It seems like it would be something simple, perhaps something that PTGui can add or edit to their file output.

 Thank you!

[digitaldog]

It sounds like ProPhoto RGB (either the profile or metadata) is being used, but some apps don't understand or recognize it. It makes sense for color-managed apps; they have no idea about color management.

[earlybird]

Hi, Thanks for considering the question.

If the Photo Viewer had not treated any of the ProPhoto RGB images properly, I would not have been as surprised. In this case, it treats some one way and others differently.

I hope to identify what is different in the image files that changes how Photo Viewer interprets them.

Thank you.

[earlybird]

...It makes sense for color-managed apps; they have no idea about color management.

I have read this sentence a few times and concluded that I do not understand what it means.

[digitaldog]

I have read this sentence a few times and concluded that I do not understand what it means.

There is a universe of software that has no idea what an ICC profile is or what different color spaces are. They assume sRGB or send the RGB numbers to the display. They don't understand or use color management, which is number management.

It sounds like ProPhoto RGB (either the profile or metadata) is being used, but some apps don't understand or recognize it.

[earlybird]

It sounds like ProPhoto RGB (either the profile or metadata) is being used, but some apps don't understand or recognize it.

Yes, I understood that sentence.

It makes sense for color-managed apps; they have no idea about color management.

This is the sentence I do not understand.



In any case, it has been my, perhaps mistaken, understanding that Windows Photo Viewer uses color management, recognizes ProPhotoRGB, and adapts the display accordingly.

In the past decade, I have been accustomed to viewing both my 8bit sRGB .jpg files, and my 16bit ProPhoto RGB .tif files in Windows Photo Viewer with no unexpected shift in color.

Photo Viewer works fine with all my ProPhoto RGB .tif files except those composited by PTGui.

This is why I am wondering why .tif files that originate in PTGui are somehow treated differently. My question is especially incited by my observation that the PTGui ProPhoto RGB .tif files seem to have tagging recognized by other applications.

This leads me to assume that Windows Photo Viewer is looking for tagging that PTGui does not include.

If I can identify the issue, I may be able to ask the PTGui developers to include the necessary tagging.


As I mentioned above, I figured out a workaround by copy-pasting from the PTGui .tif file and pasting it into a fresh new Photoshop project. There's something different between the default tagging that Photoshop uses in a new project and the PTGui tagging that Photoshop preserves if you use the PTGui tif as the first layer basis of a project.

I'm hoping someone can help.

Thank you!

 

[digitaldog]

In any case, it has been my, perhaps mistaken, understanding that Windows Photo Viewer uses color management, recognizes ProPhotoRGB, and adapts the display accordingly.

Depending on the age of the product, no then yes.

This is why I am wondering why .tif files that originate in PTGui are somehow treated differently.

It depends on how the color space is defined and how the app accesses it. ICC profile and or/metadata. Photoshop can use either.

[earlybird]

It depends on how the color space is defined and how the app accesses it. ICC profile and or/metadata. Photoshop can use either.

That is what I am assuming.

I have attached two examples.

The Source.tif is a small crop of a .cr2 photo made with a Canon 5DSR, "developed" in Adobe Camera RAW, and converted to a .tif file with Photoshop's Image Processor script. The .tif file that this was cropped out of was one of several used as source files in a PTGui stitching project.

The PTGui-output file is a small crop of a .tif file exported from PTGui trial version after the app stitched several .tif source files that had been prepared as described above.

The meta tagging differs in some ways, but the ICC tagging seems the same. Is the ICC Profile info also stored elsewhere in the file? Where and How could I inspect for differences?

[digitaldog]

Is the ICC Profile info also stored elsewhere in the file? Where and How could I inspect for differences?

It is embedded, but I can't say exactly where it is.

[earlybird]

Thank you, I can try to follow up with PTGui once/if I buy a license.

Thank you.