DNG - Open Standard not so open after all?

[solardarkroom.com]

I've always liked the idea of DNG and have adopted it, converting all my CR2 files on import. I keep backups of the CR2 but look forward to the ISO and manufacturers all coming together to stop the proprietary RAW madness(drip drip). So I was quite surprised to find an example of DNG not being completely open:

I tried a great piece of software currently in beta called LRTimelapse and was surprised to discover it did not work with DNG. I found the following remark from the developer via the forum:

"... thats a good idea, and I suppose it would work, if LRTimelapse were able to work with DNG. Unfortunately I couldn't manage to find a way to read / write metadata from / to DNG. Unfortunately Adobe doesn't provide a proper Java API."

The software's pretty clever and I'm inclined to think his problem is real. I hate to be ringing alarm bells but I do find it curious and slightly disconcerting. I suppose I should get on some Adobe forums next but I'm interested to hear any comments you folks might have.

Thanks,
David

[john beardsworth]

He can just grab the DNGs' embedded JPEGs or read/write via Exiftool.... Nothing to do with "a proper Java API".

John

[solardarkroom.com]

John:

Thanks for your comment; I'll pass it along via the forum. If I understand correctly Exiftool is the program by Phil Harvey that various developers have incorporated into LR plugins so it sounds like a good idea. By your comment I assume it can read/write metadata to DNG already. I know LRTimelapse uses the embedded JPEGs for it's de-flicker routine but beyond that I don't know.

David

[john beardsworth]

I have heard of LRTimelapse, David, but I haven't looked closely and don't know what kind of technology he's using. So I am guessing at the likely requirements. But DNGs are easy to read/write - safely too - with Phil Harvey's Exiftools library or anything else able to read/write metadata fields, and dozens of programs do so using different technologies, so I'd be amazed if he couldn't read/write. Conceivably there might be an issue if he is indeed using Java, but I doubt it. Also in this case the advantage of DNGs would be that you can update the embedded previews (under Metadata menu) and the LRTimelapse's JPEGs will include all your LR adjustments.

John

[colinb]

The standard is open. Here's my evidence.

www.adobe.com/products/dng/pdfs/dng_spec.pdf

Adobe will tell you the binary format of a DNG file. That's as open as it gets.

A Java API is a programming library written in a specific language [hopefully I'm being clear, rather than patronising; please excuse me if you find otherwise] that provides a method for a Java programmer to access the file without their having to read the actual spec. Similar APIs would be needed by programmers in C, Lua, COBOL or anything other language you can think of [RIP DEC STD 32]. And any reasonably competent programmer ought to be able to read Adobe's spec., and produce such an API library.

In contrast, a closed standard would be one in which the binary file format is not publicly available. This forces programmers who wish to fondle a file [or protocols] contents to reverse engineer the data. This is a process that is fraught with both technical and occasionally legal difficulties. Examples of closed file formats that have been reverse engineered by third parties include [or used to] Microsoft's Office files [OpenOffice], and the SMB file access protocol [SAMBA].

There's an interesting middle ground in things like the Lightroom SDK. I think its the case that Adobe don't openly document the format of the Lightroom catalog. But they do have a downloadable API, the SDK, that allows anyone with the appetite for such things to access the contents of the catalog in a programmatic way.

watcha

c

[solardarkroom.com]

Thanks for all your detailed information. I'll pass it along to the developer. My interest is simply in seeing this software achieve DNG compatibility. The concept of the beta and the way it's performed in my first tests is so encouraging that I'm eager to see it succeed. It saved me many hours of rendering batches in Photoshop and the image quality was much better in the final timelapse movie.

If any of you out there are into Timelapse, via Lightroom for example I encourage you to check it out. If you know of something better you might consider telling me!

Happy shootin'

David

PS The software referred to is LRTimelapse

[john beardsworth]

Sean of Lightroom-blog did something using SlideShow. Here you are http://www.pixiq.com/article/lightroom-timelapse-presets-now-updated-to-version-3

John

[solardarkroom.com]

Yes, that's what I was using before. The feature that attracted me to LRTimelapse was the flicker remover which automatically compensates for small discrepancies in exposure. It also allows the ramping of many different parameters in a fairly easy and intuitive way. It's probably not fair to compare the two as one is a Java application, the other a series of Slideshow presets.

Previously I was dealing with flicker by running an auto-contrast batch in Photoshop CS5, which turned into a lot more work and time than I cared for before discovering I needed to make adjustments and repeat. With LRTimelapse I can preview virtual camera pans, zooms and check for exposure flicker all in a matter of a couple minutes. I was hooked instantly.

Thanks again for your time and assistance.

David

[deejjjaaaa]

and manufacturers all coming together to stop the proprietary RAW madness(drip drip).

don't be so naive... for example Pentax (one of the few, making in total around 5% or so of the market, manufacturers that actually use DNG in camera) writes undocumented data into documented DNG format... because Adobe allows that ("...Camera manufacturers may want to include proprietary data in a raw file for use by their own raw converter. DNG allows proprietary data to be stored using private tags, private IFDs, and/or a private MakerNote..."), so you know where the big chunk of that binary data is there (inside DNG), but you don't know what it means   ... so no real difference between .PEF or .DNG, except that .PEF is fully supported by more raw converters (you do not have full in camera DNG support for example in C1 for Pentax DNGs).

[john beardsworth]

Here you go again..... MakerNotes are deliberately defined within an open format. Real differences include3rd party raw converters being able to update or add extra embedded previews and safely write metadata. Yawn.