Color management in creating HTML galleries from iView

[Rick McCleary]

Hi Peter -

Tthumbnail and media views in iView show accurate color - I'm assuming because they are showing the embedded (and sRGB tagged) JPEG in the DNG file.  When I create an HTML gallery, however, the color goes south.  In looking at the image files in the resulting html folder, there is no profile embedded in the .jpg's.  iView is not color managing the creation of the HTML gallery image files.

Under Actions: Manage Color Profiles, there are no options available because iVIew is seeing the DNG, not the embedded JPEG.  

How do you manage the color in your HTML galleries?  Is this something you can speak to Yan about?  I know that eveyone's monitor is different, so it's probably not worth losing a lot of sleep over, but I'd at least like things to look as perfect as possible before they leave my shop.

(I'm also posting the question on the iView forum.)

Thanks - Rick

[peterkrogh]

Rick,
Ae you doing this in 3.x?  Do you have "preserve color profiles" checked in the Settings tab of the Mke HTML dialog?
Peter

[Rick McCleary]

I just checked the iView forum.  There are some questions that reflect a confusion about color management in general, but nothing specifically about broken color management in creating the HTML galleries.

To reiterate, the views in iView (thumbnails, media) are accurate.  The problem is in the creation of the image files for the HTML gallery.  There are some obvious workarounds.  For example, in ACR, I could open all the DNG's as sRGB JPEG's, save them to a folder, then bring those into iView and create the HTML gallery from those.  That seems like double work, though.  iView should be able to extract the JPEG from the DNG and properly color manage it in creating the HTML gallery image files.

To those of us who are creating lots of web galleries for our clients, the HTML gallery feature is a very important part of the iView software.  Unless I'm missing something obvious, this is a seious problem that needs to be fixed.

Yan?...

[Rick McCleary]

Rick,
Ae you doing this in 3.x?  Do you have "preserve color profiles" checked in the Settings tab of the Mke HTML dialog?
Peter

Yes and yes.

[peterkrogh]

Rick,
I took a look at it, and it seems to be in Colormatch space, rather than sRGB. (open the image and assign colormatch profile, it makes a very close match to what the DNG looks like if you open it ).  I'll ask the powers that be what's up with that.
Peter

[Rick McCleary]

Peter -

Thanks for looking into it.  I'm out of town right now and have not had time to totally analyze the problem.  I want to test to see what happens if I create a gallery of tagged JPEG's.  If the tags are properly preserved, then the problem is only in how iVIew deals with DNG's.  If it throws away the JPEG tags, then the problem is more fundamental.

One possibility is that the HTML gallery engine arbitrarily ASSIGNS a profile (like Colormatch) and then saves the file without embedding it -- a colossal breakage of color management!  Only after looking at the actual script that is used will answer the question.

Lete me know what you find out from Yan (or whoever "the powers that be" are!).  I'd be happy to brainstorm with you/him/them on this.  It's gotta get fixed.

Rick

[peterkrogh]

Rick,
I did a test:
Open a DNG and look at it in Photoshop
Have iView Create a JPEG from the DNG. The JPEG comes out untagged, because the preview technically does not have a profile.  If you assign sRGB, the jpeg looks dark. If you assign Colormatch, it looks just like the conversion file made straight from the DNG.  My conclusion, the embedded preview is coming out as a Colormatch file.

I have asked Yan and the Adobe teeam to look into this.  I don't think it will be hard to have iView convert the JPEG to sRGB.
Peter

[Rick McCleary]

Peter,

I alos conducted a test:

Open a DNG into CS2 through Camera Raw; choose sRGB in Camera Raw.

Using iView, convert same DNG to JEPG.  (I did this by creating an HTML gallery containing this image and using the .jpg file iView generated which is located in the resulting Gallery: Source; Image folder.)

Open both files in CS2 for comparison.  My conclusions are a bit different from yours.

The ACR-generated JPEG is properly tagged with sRGB and displays accurate color.
The iView-generated JPEG is untagged and displays poor color.  When assigning a profile to this JPEG, none of the working space options (Adobe98, Apple RGB, Colormatch, and sRGB) come close to the CS2 JPEG.  In the Assign Profile dialog box, a preview of sRGB shows the LEAST difference between the untagged view and the assigned view.  This indicates to me that the untagged file is closest to an sRGB color space. 

However, assigning sRGB to the iVIew-generated JPEG does not fix the problem.  The color is still off.  It has a distinct blue cast in the shadows as if the black point has been remapped.

I can't imagine what iView is doing to this file.  Only by looking into the programming of the HTML Gallery engine can we understand.

Another question relates to how DNG is handling the generation of the JPEG.  Perhaps the problem is in the DNG Converter.

Let me know how your conversations with the iView and Adobe folks go.

Rick

[peterkrogh]

Rick,
Thanks for catching this.  I had been meaning to run this test, but had nnot gotten around to it. The fix will be forthcoming. Here's the issue:

When you make the JPEG out of Camera Raw, Photoshop is making the file from the RAW data.  It opens it up, applies the internal "profiles" in Camera Raw, and makes a conversion file with the profile that is indicated in the workflow options of Camera Raw dialog box.

iView is making use of the embedded preview.  This IS an sRGB file, but because it is an embedded preview, it has no actual profile embedded.  Yan is working out exactly how to work with this file as he extracts it.  It should not be terribly hard to make this work.

As to the match of the iView extraction and the Photoshop conversion, I wonder why yours does not match?  Is it possible that there was a mismatch between the embedded preview and the conversion file due to a mismatch of settings?  Do you have your Camera Raw preferences set to Always Update the preview? Did you adjust the image in Camera Raw as you opened it?  Are you trying this with an iView conversion file (Action>Convert Image File...) or an HTML gallery file?  When you open it into Photoshop, do you assign Colormatch when you get the missing profile warning?

[Rick McCleary]

When you make the JPEG out of Camera Raw, Photoshop is making the file from the RAW data.  It opens it up, applies the internal "profiles" in Camera Raw, and makes a conversion file with the profile that is indicated in the workflow options of Camera Raw dialog box.

This makes sense and works the way it should.

iView is making use of the embedded preview.  This IS an sRGB file, but because it is an embedded preview, it has no actual profile embedded.  Yan is working out exactly how to work with this file as he extracts it.  It should not be terribly hard to make this work.

When you say that iVIew is using the embedded preview, are you referring to the "pretty good print" JPEG that is in the DNG?  If so, and if it is an sRGB, then why is there not a profile embedded in the JPEG?  Is this an Adobe problem?

As to the match of the iView extraction and the Photoshop conversion, I wonder why yours does not match?  Is it possible that there was a mismatch between the embedded preview and the conversion file due to a mismatch of settings?  Do you have your Camera Raw preferences set to Always Update the preview? Did you adjust the image in Camera Raw as you opened it?  Are you trying this with an iView conversion file (Action>Convert Image File...) or an HTML gallery file?  When you open it into Photoshop, do you assign Colormatch when you get the missing profile warning?

I'm still trying to figure that out.  I have checked and triple-checked my color settings.  In order to run a consistent test with as few variables as possible, I did not adjust the ACR settings (exposure, shadow, color temp, etc.). 

I have generated the iView conversion both ways (Make: HTML Gallery... and Action: Convert Image File...).  Both methods generate an untagged RGB file.  Both methods generate the exact same color problems.  However, curiously, Convert Image File... generates a file that is consistently about 10 points darker (on a 0-255 scale) than Make: HTML Gallery.  What do you see when you do same test?

BTW, when I open the iView-generated files in CS2, I choose to leave the file as is (no color management), so I can try different profile assignments in Edit: Assign Profile...

Curiouser and curiouser...
Rick

[peterkrogh]

>When you say that iVIew is using the embedded preview, are you referring to the "pretty good print" JPEG that is in the DNG?  If so, >and if it is an sRGB, then why is there not a profile embedded in the JPEG?  Is this an Adobe problem?

Not an Adobe problem, just a limitation of the format.  There are two image files in a DNG: the Preview and the RAW image itself.  I believe it would cause all kinds of confusion for the two files to have different tags embedded.  So instead, the preview IS an sRGB file, just not tagged as such. It's up to the extracting application to assignn the sRGB profile upon extraction.

>BTW, when I open the iView-generated files in CS2, I choose to leave the file as is (no color management), so I can try different profile >assignments in Edit: Assign Profile...

I think this is the mismatch.  Try assigning a colormatch profile when you open the file, then convert to sRGB after you have opened it.  Do you get a match?

[Rick McCleary]

I think this is the mismatch.  Try assigning a colormatch profile when you open the file, then convert to sRGB after you have opened it.  Do you get a match?

No. 

You get the exact same results in either of the following cases:
Open an untagged file. In the mismatch dialog box, choose "leave as is", then Edit: Assign Profile...
Open an untagged file. In the mismatch dialog box, choose Assign Profile.

[peterkrogh]

Interesting.  I'll try it again.  BTW, Yan tells me that there will be a new beta today that fixes the problem.  Will report back after I try it.
Peter

[Rick McCleary]

Peter -

Any word from Yan on the new beta?

Rick

[peterkrogh]

Rick,
I was just about  to post...

Here is a new build:
http://www.iview-multimedia.com/beta/

I also think I know what might have been going wrong yesterday.  Did you have the "colormatch" box checked in the Preferences>Media Rendering>Images panel?

I just ran a test, and the result from iView and from Bridge were 1 point away on two colors, and an exact match on one color.  Close enough for proofing.  The image file came in with an sRGB profile.

Very slick.