Which applications use the embedded JPEG previews in a DNG image?

[Louie Sherwin]

I am looking to revise my workflow. I currently use IIP to ingest my RAW image files, make backups and convert to DNG. I have always specified "Full-sized" JPEG Preview" as part of the conversion process. I also have specified "Update embedded JPEG previews: Full Size" in my ACR preferences. Then I use Bridge to evaluate, select and develop with ACR the images I want print.

I have always known that ACR used it's own 100% previews that will be built on the fly or can be created with the "Build and Export Cache" on the Tools menu. In fact I usually do this after each import to speed up the image evaluation  process in Bridge as waiting for the previews to built on the fly was just to agonizingly slow.

Recently I started to evaluate Lightroom 3 beta thinking that overall it might be a simpler more efficient solution for me. I was somewhat surprised so discover that it too has to build it's own previews. This leads me to wonder if I am just wasting my time building the full sized previews at import and then having them recreated every time I make any new adjustments in ACR or Lightroom.

Right now the only software that I know that uses the embedded preview is  Expression Media( and iViewPro). This clearly speeds up the workflow when generating output form those applications. If this is true I now don't see any advantage to creating these previews until and unless I decide to continue using EM2 (or the hinted at successor).

Do I have this right or am I missing something?

-louie

[ianw]

Louie,

I've used the Light Table facility within iView and xMedia for some time now.  Recently had to get a new Windows laptop and decided to reinvestigate the WIC position, as on my XP based desktop xMedia can't handle my Olympus ORF files.  In fact I was using the more reliable iView!  I was converting to DNG to get around this.

I found a new piece of software called Fast Picture Viewer and downloaded it for a trial ( http://www.fastpictureviewer.com/ ).  Wow!  It's rare that a piece of software blows me away but its speed did that.  I think iView was the last such software to have a similar effect, although for other reasons such as interface and functionality.

Anyway I pointed it at a directory of DNG files and it allowed me to review the images almost as quickly as I could scroll through them.  For example I took almost 300 images in a studio shoot last night.  This morning it took me less than 5 minutes to review them and get rid of the blurs and blinkers and flash misfires.  Previously, in xMedia, this would have taken 30 minutes.  Needless to say I have bought the software and consider that within a month it has more than paid for itself.

It is Windows only but it appears the author really knows how the operating system handles images.  It comes bundled with a big selection of WIC Codecs, so my Olympus ORF files now show as images in Windows explorer, as do the DNG files.  As it can use the built in JPG this means you don't need to go to DNG - I prefer to as my files have reduced size JPGs not ideal for review purposes.  It also works best on Windows 7 over Vista over XP - i.e. it makes use of newer features.  Therefore it won't go on to my desktop until that gets upgraded.

Hope this helps.

Ian

[Louie Sherwin]

Hi Ian,

Thanks for the comments. I'll guess that Fast Picture Viewer is reading the embedded previews. Too bad it's only on Windows.

Regarding the slow display in LR3 beta, I checked the discussion group and found that there is a known problem with building previews and not likely to be fixed until the real release. It seems ironic that built in full sized previews is one of the touted features of Adobe's DNG but non of their applications give you the option to make use of them.

-louie

[peterkrogh]

Louie,
The function of the full sized embedded preview is really to enable the rendering of the file to be portable.  If you are always going to stay in a asingle environment (such as Lightroom), then there is no need to build these on a regular basis. Whenever you want to pass the image to software that does not own the Adobe rendering engine, then the preview *may* become very valuable, and you would want to make sure it's updated. (You need to test and see what the software "sees", and determine that it's of use in the task at hand.)

Bridge in CS4, BTW, has a setting to display embedded preview only. (It's in the preferences, and in the toolbar).  This can make use of the preview to speed up display.

I agree that Lightrom should make better use of these, but there is a somewhat complex user understanding issue. Many (probably most) Lightroom users don't have a really good handle on exactly what they are seeing at any particular point in the program.  Live rendering, draft-quality cache rendering, full-quality cache rendering, or proxy preview (for file types that it does not understand, suc as through Jefrey Friedl's plug-ins). This can be really confusing.

Lightroom has been reluctant to open the Library up to more confusion, until they can get a really good handle oon how to make the user understand what they are seeing. If we add "embedded preview (not live, full-quality rendering) for files that Lightroom can render", and, worse, "embedded preview that does not currently match the state of develop sliders", then there is the real potential to make users confused.

The DNG format does have built-in capability to help sort out this confusion.  There are tags in the file that describe what settings were used to make the preview, so Lightroom *can* know if the preview is up-to-date or not.  There is some significant UI design required, as well as the engineering that is required to make use of the previews.

It's not as simple as one might hope.
Peter

[Louie Sherwin]

Hi Peter,

I concur with your description of the purpose intended uses of the embedded preview. It is why I have set my preferences to keep them up to date. As you point out the actual usefulness depends on the follow on application. From your work we know that EM2 can use it it you configure it to. Also it appears that Fast Picture Viewer will also use the preview present in a DNG to display the image.

With respect to Bridge CS4  I finally found the two buttons on the tool bar. They only appear if the "Path Bar" is turned on. In any case these seem to affect only the standard size preview and the thumbnail but not the 100% view which is still very slow to generate on the fly. Even with "Prefer imbedded" checked there is a long pause when you request a 100% view. This is true whether or not I have selected "Generate 100% Previews" or if I have  "Keep 100% Previews in Cache" selected.

So for my purposes because I depend so much on 100% views for image evaluation I will continue to manually build the cache and previews immediately after I import a shoot. And I will  probably not even convert to DNG at any more.

Your comments regarding choices the Lightroom has to consider reflect a larger challenge that has already bitten the Lightroom team. The inclusion of the Process Version in LR3 Beta illuminates the fact that the application algorithms are just as important to the image creation process as is the capture data and the process parameters. This is likely to become more rather than less complicated as tools an technology move forward.

tks, louie

[peterkrogh]

>Your comments regarding choices the Lightroom has to consider reflect a larger challenge that has already bitten the Lightroom team. The inclusion of the Process Version in LR3 Beta illuminates the fact that the application algorithms are just as important to the image creation process as is the capture data and the process parameters. This is likely to become more rather than less complicated as tools an technology move forward.

Louie,
And makes DNG even more important.
Peter