Adobe Releasing New Photo Format 422
salmonz writes "Toronto Star just posted a story that Adobe is releasing a new digital picture format; the Digital Negative Specification,or DNG.
" Supposed to be use in raw photo formats; without the lossyness of JPEG.
I can't remember... (Score:5, Funny)
Re:I can't remember... (Score:2, Insightful)
Yes, and we're also supposed to grumble about how Adobe is going to pull a submarine patent on this format to lock out the GIMP.
And my whole point was... (Score:4, Informative)
This is just a graphic file format like any other, using bog-standard compression and metadata standards. It's just a more standard bag for raw camera data than what we've seen before.
Re:And my whole point was... (Score:5, Funny)
Re:I can't remember... (Score:3, Interesting)
Remember, however, that Elcomsoft are associated with spammers [spamhaus.org]
Re:I can't remember... (Score:3, Funny)
You go first.
Maybe (Score:3, Interesting)
--
Re:Maybe (Score:5, Informative)
I'm not horribly concerned if Nikon doesn't release an update for my particular camera since Adobe will be providing an image conversion utility that supports many of the proprietary raw formats.
Re:Maybe (Score:3, Informative)
Perhaps because it's an effective method to get everyone playing nice. There *are* other lossless formats that camera manufacturers could support (and I'm sure some do), but with no real direction, everyone would just do what suits them and there would likely be no common format between them. Adobe is just trying to help give the camera manufacturers something to agree on (barring other possibly nefarious intentions).
Re:Nope, just have to get photographers using it (Score:3, Informative)
TIFF is also a format that most camera makers are already comfortable with. The files that come out of most cameras conform to the Exif spec. Exif is the JFIF (JPEG) file format with metadata embedded using TIFF tags. It will be interesting to see (I haven't read the specs yet) whether Adobe wants to keep any or all of the Exif tags, or wants to ignore them and invent t
Supports EXIF and more (Score:3, Informative)
Re:Nope, just have to get photographers using it (Score:3, Informative)
The most useful tag is DateTimeOriginal, which tells you when the photo was taken. Some cameras also record info like shutter speed, flash s
Great idea. Some info. (Score:5, Informative)
Re:Great idea. Some info. (Score:5, Interesting)
Which shouldn't be a worry for the vast majority of cameras that use square pixels in a RGB Bayer array. I'd expect that it would be pretty easy to deal with other square pixel Bayer arrays, like Sony's RGBE and the occasional CMY. Non-square arrays, like the ones used in some Nikon pro-series SLRs, and non-Bayer setups, like Foveon's X3 system, might be harder, but I'd expect that they could be accomodated without great difficulty.
Re:Great idea. Some info. (Score:3, Insightful)
The problem is that the fundamental data isn't standardized -- the RAW data is the signal straight from the CCD, and that's very different depending on the specifics of the CCD. For example, some high-end cameras have three separate CCD's (much, much clearer image, particularly in low light), Fuji CCD's are just weird, etc. So the RAW formats are all very proprietary, not only per manufacturer, bu
Customer oriented naming (Score:5, Insightful)
I have read up on how using the raw format of the camera, and using the software on the PC you can use the additional information the camera would have thrown away, to do things such as save areas that would have been captured to dark otherwise.
Of course, each cameras format for RAW is basically that, RAW format, and this proposed file format should be nothing more than making sure each software can access it seamlessly.
So in fact, reading the article, it woudl seem like a good idea...
until you look at PDF. I just hope they don't try and put some tagging / watermarking / superflous junk into it.
*cough*
Re:Customer oriented naming (Score:3, Insightful)
Why is that superfluous? I bet you law enforcement would JUMP at a digital file format where they have an encapsulated proof within an image that the image has not been adultrated, as would insurance companies and such, and many other uses I can think of. Heck, as a photographer, I'd like it for protecting my own copyright.
Re:Customer oriented naming (Score:3, Insightful)
*Sigh* - you can do reasonably tamper-proof harware, so that it would be pretty much impossible to get at the cryptographic photo-signing module without letting it destroy itself. But you miss the point.
Court evidence is all based on a chain of custody. Cop A stands up and says "I collected empty casings from the scene and placed them in a bag labelled "blah", and gave them to examiner
Re:Customer oriented naming (Score:4, Informative)
my digital rebel I take a "black mask" shot every night I start a sky photographing session. I'm looking at 25-60 second exposures (multiples to get even longer exposures) and when I subtract a black mask from the images I remove most of the unwanted ccd noise. (simple script under linux in C to work with the RAW files.) I can not accomplish the same quality by doing a black mask on Jpegs or in photoshop with the RAW plugin I bought for it.
The same goes for stacking images to get a better exposure. performing this on the native RAW images produces crisper results.
Calibration images for astronomical photos (Score:4, Informative)
To get a corrected image, use this formula for each pixel:
newimage = (image - dark) / (flat - dark)
Better yet, take a bunch of darks and flats and median-filter them to get rid of cosmic rays which can introduce spurious glitches in the images.
JPEG-2000? (Score:5, Insightful)
What about using the new version of JPEG, for 'digital negatives'?
There are no royalties, no licencing, it has 2x to 5x the compression efficiency, and it's inherently multiresolutional. One file, all resolutions, no reprocessing.. It supports hundreds of component layers, data embedding, lossless encoding..
So.. why would you use some new proprietary Adobe format?
Re:JPEG-2000? (Score:5, Interesting)
Adobe has traditionally understood the value of releasing full file specifications under a non-restrictive license, as they have done with PDF and PS.
They have no motivation to make this standard proprietary, if they did that, digital camera makers wouldn't use it! All signs point to them making this one completely open.
Re:JPEG-2000? (Score:3, Informative)
Re:JPEG-2000? (Score:3, Interesting)
PDF 1.5 is Adobe's current standard and soon followed by PDF 1.6.
Mac OS X utilizes PDF 1.4 and soon PDF 1.5. Adobe licenses prior versions of PDF to be royalty free which only makes sense--give them a taste to what PDF does and encourage them to purchase the latest version to leverage all that PDF can do.
We had a huge pain in the rear issue with Adobe at NeXT and then Apple dealing with Display Postscript--even though we co-developed the standard and actually perfected it. After mont
Re:JPEG-2000? (Score:4, Informative)
There are no royalties, no licencing, it has 2x to 5x the compression efficiency, and it's inherently multiresolutional.
Actually, Adobe did a very similar thing: they took the TIF format (the industry standard storing images with lossless compression) and added a few special fields, using the extension mechanism already provided by TIFF. As far a I can see, Adobe doesn't intend to charge royalties for DNG. It looks quite open -- even the DNG guide for manufacturers doesn't mention any licensing requirements.
(Adobe's DNG web site [adobe.com] is already online.)
Re:JPEG-2000? (Score:3, Informative)
They're filling the format with lots of structured metadata that can give you all the information you need (and probably also some you don't need
You could look at a photo and say "Hey, I like the way the details are emphasized in this photo. Let's see which settings he
Re:JPEG-2000? (Score:3, Interesting)
The greatest advantage of photographing in RAW is that you can adjust the white balance long AFTER t
Re:JPEG-2000? (Score:3, Informative)
I like my photo formats RAW (Score:2, Interesting)
Parent is uninformed (Score:5, Informative)
This format is about putting all RAW files under one (DNG) format.
Eg. Nikon has NEF, Canon has CRW, Olympus has xxx, adsf has yyy....
Isn't it better to have one open/standard format which all manufacturers support/endorse?
If you are skeptical read this. [adobe.com]
Re:I like my photo formats RAW (Score:3, Insightful)
The biggest advantage digital cameras give you over film is the flexability to NOT get it right the first time. Aside from the power to take a large number of shots to experiment with ideas you wouldn't otherwise give the time of day, it also allows you to fix things you didn't notice when you did take the image. If you just want to shoot once and hope
Hopefully... (Score:5, Insightful)
I await more information and a working open-source library...wake me when it's ready.
Re:Hopefully... (Score:5, Insightful)
Preservation of digital photography in RAW formats is an ugly challenge and kudos to Adobe for taking the lead in a very serious issue. This is not a marketing ploy - in fact, if you understand the effort you'll see it's a very open attempt, and in some ways will be subsidized by Adobe - for instance, their DNG Converter will continue to provide the capability to convert any RAW format they support into DNG, leaving other DNG developers to focus on the act of processing DNG images and not on reverse engineering every new model camera's RAW format.
Full press release link from DPReview (Score:5, Informative)
Adobe Systems has today announced a new unified public format for raw digital camera files and a free software tool, Adobe DNG Converter, for translating raw photo formats into the new .DNG format, which is
compliant with the Digital Negative Specification. There is no standard
format for raw files, which vary between manufacturers and cameras.
Digital Negative Specification will introduce a single format that can
store information from a diverse range of cameras. An updated Adobe RAW
File Converter adds support for DNG as well as several other cameras.
Click here for more information on Adobe DNG [adobe.com]
Press Release:
Adobe Unifies Raw Photo Formats with Introduction of Digital Negative Specification Free Converter Tool Kick Starts New Digital Negative File Format by Translating Raw Formats into Easy-to-Use, Archive-Ready Files
SAN JOSE, Calif. -- Sept. 27, 2004 -- Adobe Systems Incorporated (Nasdaq:ADBE) today introduced the Digital Negative Specification, a new unified public format for raw digital camera files. The company also launched a free software tool, Adobe DNG Converter, which translates many of today's popular raw photo formats into the new .DNG file format, compliant with the Digital Negative
Specification.
Raw files, which contain the original information captured by a camera sensor prior to any in-camera processing, have become popular due to their promise of greater flexibility and image quality. Until today there has been no standard format for these files, which vary between manufacturers and individual cameras. The Digital Negative Specification solves this problem by introducing a single format that can store information from a diverse range of cameras. Technology leaders, major customers, and professional photographers today also endorsed the new specification (see separate quote sheet).
"Professional photographers and other creative professionals are moving to raw camera workflows because of the outstanding creative control they get over digital images," said Bryan Lamkin, senior vice president of Digital Imaging and Digital Video products at Adobe. "However, clients and publishers have difficulty working with disparate raw file formats and nobody can be sure that today's raw formats will be supported ten years from now. Adobe customers asked us to work on a unified, public format for raw files and that's what we've delivered with the new Digital Negative Specification."
Serious photographers want to store raw files in long-term image archives, because -- unlike standard JPEG's and TIFF's -- these files represent the pure, unaltered capture. Current raw formats are unsuitable for archiving because they are generally undocumented and tied to specific camera models, introducing the risk that the format will not be supported over time. The unified and publicly documented Digital Negative Specification ensures that digital photographs can be preserved in original form for future generations. The new .DNG file format also simplifies digital imaging workflows for
creative professionals who today have to juggle multiple file formats
as they bring raw images, from different cameras, into print and
cross-media publishing projects.
New Specification Built on Existing Standards
The Digital Negative Specification is based on the TIFF EP format, an accepted standard, and already the basis of many proprietary raw formats. The power of .DNG format lies in a set of metadata that must
be included in the file to describe key details about the camera and
settings. .DNG-compliant software and hardware can adapt on the fly to
handle new cameras as they are in
What a stupid name (Score:4, Insightful)
The images stored in ths format will not be negatives (i.e. inverted) anyway, contrary to what the name means and suggests.
Re:What a stupid name (Score:5, Insightful)
In this sense, negative is the ideal name.
If I see one more "what's wrong with PNG" post... (Score:5, Insightful)
Re:If I see one more "what's wrong with PNG" post. (Score:3, Funny)
That can be very embarrassing in a lab environment.
Insert AOL! here. (Score:3, Interesting)
As for myself, I've been eagerly waiting for an influential company to propose something like this; I work in a pro lab, and having to master and keep up to date on a dozen different raw converters is very stressful. A single standardized open format that I
Re:Rant much? (Score:3, Interesting)
It's quite simple why TIFF is a better choice for adobe: they own it and are familiar with it.
Your troll tried to use the "technical" argument to throw off the point of my post. My post wasn't about technical merit, it was about typical slashdot groupthink. You don't need a technical argument, you need an argument of simple economic
Adobe's take on the issue (Score:5, Informative)
There are currently two image formats in wide use for high-end cameras. RAW is the format of choice for people who demand high-quality shots with no compression artifacts. Unfortunately, different camera manufacturers have implemented their RAW encoding differently, which means that two cameras that can save to RAW don't necessarily use the same format. As a result, professionals often have to convert between their vendor's RAW format, and that used by their software.
The other format is good old JPEG, but as you probably know, JPEG is a lossy compression [webopedia.com] algorithim, making it unsuitable for those who demand a certain level of quality in the shots as captured.
The new format is designed to provide the same advantages of RAW, without the cross-vendor incompatibilities. Adobe is calling it "a publicly documented and readily available specification," although I didn't see any kind of license data around the download of the spec (which is on the Adobe page listed above).
This actually does make sense, odd as it sounds. (Score:5, Insightful)
Most digital camera manufacturers came up with their own lossless compression. And, of course, they're all incompatible.
Now, why Adobe? If you're shooting high-end digital photography where you care about it being lossless, and you're doing post-production on your images, what are you using? Adobe Photoshop. So instead of having to have input routines for Photoshop for seventeen different specs, Adobe would much rather the manufacturers have one standard-- can't say as I blame them. Standards are good.
Now, most of us will still keep our cameras set to shoot JPEG, but the folks who do this stuff for a living, this will benefit them. This isn't a case of trying to create a new standard to replace one that already exists to try to get market dominance, a-la Microsoft (or, heck, Acrobat/pdf for the most part...), this is a new standard to make up for the fact that there simply isn't one in this segment and there desperately needs to be.
Now, this doesn't mean Adobe won't leverage the spec and make piles of cash off of it, but at least in this case they're actually inventing something that people need instead of trying to push something on them that they don't.
More info available ... specs too (Score:5, Informative)
Adobe already has a page [adobe.com] on DNG. Its is a free format and the specs are right there on the page, so GIMP won't lose out.
I believe the format is a) to save Adobe money long term (they don't have to support yet another specific sensor) and b) reduce headaches and complaints from the user. We'll just see how the camera companies and digital photography professionals react.
Re:More info available ... specs too (Score:5, Interesting)
Adobe is leveraging their reverse engineering work in providing the free DNG Converter - this will actually benefit smaller developers more than Adobe, as they will only have to tell their users to download DNG Converter to move their RAW into DNG - the third-parties can focus on supporting DNG and providing excellent processing tools, while Adobe will continue to do the hard work of camera support (until the cameras produce DNG directly - which is of course the long-term goal).
Why this is a good thing (Score:4, Insightful)
Each camera has there own RAW format. Read each Manufacturer has their own proprietary format. Some even have multiple formats. For example, Nikon uses
Photographers work with RAW because it is lossless and can be recorded with 16 or 12 bits of data per pixel, where JPEG and TIFFS tend to be 8 bits per pixel. Also, as mentioned already, settings such as white balance, tone, sharpness, color, and even exposure compensation can be applied after the shot was taken.
BTW: Post-Processing is a HUGE part of Digital SLR photography for those that are only used to the Point and Shoot cameras.
Now for why it is a good thing to have a unified RAW format. I recently purchased the Canon 20D. It included a new
With each new camera release, all software writers will have to update their program if they want to support the new cameras. At the rate at which DSLR's seem to be announced this could be a huge pain. If a company like Adobe could convince the market the their DNG file is the way to go, your software would only have to work with that format.
Less why, more how (Score:4, Informative)
Ignoring the differences in the various RAW formats between manufacturers, what about differences between two cameras from the same manufacturer ? What causes that and would DNG cater for it ?
As an example, look at the Nikon D70 and the D100. Adobe had full support for the D100 with their ACR (Adobe Camera Raw) plugin. But when the D70 came out, we waited months for true compatibility with Photoshop (yeah, yeah, you could use the nikon supplied plugin, but that was worthless really).
I'm guessing Adobe want this because in order to keep selling Photoshop to photographers, they have to keep amending ACR everytime a new camera comes out. But can a fixed standard cater for everything that Canon and Nikon will be putting in their cameras, and want to store in the RAW files 2 years from now ?
Oh great, now we have to deal with new terminology (Score:5, Funny)
Dude2: "Hey Dude, I have a funny picture to send you"
Dude1: "Dude, wait, I have dialup and it's gonna take forever"
Dude2: "No way dude, it's a ding, it'll only take a moment, here it comes"
Dude1: "Okay, got it
Key benefits from DNG primer (Score:5, Informative)
Image format: DNG is based on the TIFF-EP format, but DNG specifies the inclusion of a number of additional tags that let the converter properly interpret the raw file.
Metadata: DNG enables inclusion of metadata in EXIF, IPTC, and XMP formats.
Compression: Files can be stored as uncompressed (either bit-packed or padded to 16-bits per pixel) or with lossless JPEG compression.
Color space: DNG fles are stored in a linear, nonwhite-balanced color space (usually the native color space of the camera).
Interpolation: DNG enables file storage either in mosaic (CFA) form or in demosaiced form. Generally, a mosaiced file is preferred because it represents the original data the sensor captured and enables maximum conversion fexibility. It is also smaller than a demosaiced file. In some instances, however, saving a demosaiced file can improve compatibility, particularly if the camera sensor contains an unusual mosaic pattern that all converters do not support.
Adobe technology is well thought out (Score:4, Insightful)
In my opinion, working with the bare bones of their technology, ALL of it is well thought out, comprehensive and well explained.
They consider all of the difficulties of the problem domain. For instance, see how easy it is in PDF to create changes to an existing document, great for low powered CPUs. Just append the changed object and add on a new footer to the file. 95% of the file retained, which is a lot less expensive than re-generation of the whole file.
I think Adobe will do a good job here and post the specifications ala PDF and Postscript.
Not mentioned in the other comments is the run time hardware cost of saving this Digital Negative. I think Adobe will put effort into making this as friendly to integrated hardware capture as possible. A large portion of this has to be very little re-ordering of data as it comes from the CCD, as these usually require an in memory buffer. This fundamentally changes the nature of the format.
Finally Raw interoperability. (Score:5, Informative)
This provides a common RAW format for cameras. This is not a png or jpg replacement, but a RAW replacement.
There are a number of third party RAW converters on the market right now. Many have limited camera support. You can bet they will quickly moving to support DNG. Which will instantly open up their usage to almost all current cameras.
With DNG support and Adobes converter you will soon be able to open just about any RAW image with any converter.
Even without camera output this is a benefit. As you can get one converter to support all your cameras.
You can archive all your RAWs as DNG and not have to worry that you kept all the software that came with the camera that generated the original RAW.
Camera support would be even better, but that may be slow as the manufactures may suffer "Not Invented Here" syndrome, or see value adds to their own format quirks.
this is a sensor data format specification, really (Score:4, Insightful)
DNG is a format for storing the data recorded by the CCD's in a digital camera. This data can of course be processed and displayed as an image, but DNG really isn't an image format exactly.
DNG is TIFF -- Dont Panic ! (Score:5, Informative)
A DNG-format file is fully compliant with the TIFF 6.0 Specification Standard and the ISO TIFF-EP codification of that spec, which was designed from day one as a fully extensible raw, processed, or whatever image / metadata annotation spec.
BTW, TIFF was originally designed for offset printing folks, and in the 6.0 standard already supports a huge number of colorspace models besides RGB, and has an extensible mechanism for specifying color-data encoding and compression schemes (you can even store JPEG encoding in TIFF).
When I worked at the ground-data processing section of the Jet Propulsion labs, TIFF was occasionally used to store and transmit raw multispectral satellite data, which consisted of over 256 separate color-spectra bands from far infrared to ultraviolet, stored spatially in separate tiles.
Working together with Spot Image and other satellite providers, NASA also helped develop the GeoTIFF extension to TIFF, which annotates an image with exact georeferencing information.
It looks like Adobe went the route of using SubIFD's to define the extended data. A little bit unfortunate, since that data will not show up in a "tiffdump" listing of the file, but in any case I have no doubt that folks are already taking the spec and writing "libtiff" extensions to parse the stuff.
For more information on TIFF, see my old, clunky website that is chock full of invalid links,but still has a few useful things to say:
http://home.earthlink.net/~ritter/tiff [earthlink.net]
--Niles (original GeoTIFF and TIFF webpage author)
It's not bad, but... (Score:3, Insightful)
But -- I think that digital cameras are still *way* too new for this kind of standardization. Significant true innovation is happening at a frenetic pace, and if we limit RAW formats to a preconceived format we may inadvertantly (or advertantly, I suppose) squelch that innovation. Fuji's spectacular sensor with separate sensors at each pixel for dark and bright values is an example -- how would that be encoded here? One might well have a camera with vertical and horizontal polarizers on every other cell, to allow post-processessing to reduce or enhance specular highlights. Cameras could be built with psuedorandom placement of cells, to eliminate aliasing artifacts (Why not? It's not as if the semiconductor masks are laid down by hand anymore.)
In short, I think that this format could end up being a Procrustean bed that we force camera makers into, and that it's not worth it at this point.
Thad
Re:Why? (Score:3, Funny)
Re:Why the need to diss Adobe? (Score:5, Informative)
For more details about this announcement, go to dpreview.com
Adobe announces new format for raw files [dpreview.com]
The Digital Negative Specification is being posted to the Adobe Web site free of any legal restrictions or royalties, enabling integration of the
Re:Why the need to diss Adobe? (Score:5, Informative)
Those two together let you play with the image composition before its set into any format. Don't like the exposure? Check what the exposure setting was, then recalculate the pixels based on the original source data. Bad aliasing effect? Try again from the raw data at a different resolution or different interpolation between the CCD sensors and pixels and see if you can save the picture.
Re:Why the need to diss Adobe? (Score:4, Informative)
Well, a raw file is a lot more compact, and it does not do anything to change the artifacts and or "lossyness" of the sensor itself.
For instance the Canon cameras use a Bayer sensor. Imagine a checkerboard where half the sensors, are green , arranged in a checkerboard pattern, and the other half the sensors alternate between red and blue. The 12 bit value of each sensor site is encoded as the eight bit difference between it and the nearest same color site to its left. ( Amiga developers will find this vaguely familiar) The theoretical case of there being a full 12 bit difference between 2 sites never happens due to the optical properties of the camera and lens.
Re:Why? (Score:5, Informative)
Re:Why? (Score:5, Insightful)
They mention JPEG because that's usually the options you have on a digital camera; proprietary RAW format, which Adobe is trying to standardize, or standardized JPEG, which professionals don't want to use because it's lossy.
It's a good idea, as long as the standard isn't "owned" by Adobe.
Re:Why? (Score:5, Informative)
The JPEG standard includes a lossless option too; professionals don't want to use JPEG because lossless JPEG is inefficient, not because it doesn't exist.
Re:Why? (Score:3, Informative)
Photoshop and PSP allow you to save files as lossless JPEG, but the only camera I know is the newest Canon digital SLRs. Most other professional digital SLRs and prosumer cameras only store proprietary RAW, then some level of lossy JPEG.
Re:Why? (Score:3, Informative)
Re:Irony of life, DNG can be lossy too (Score:3, Informative)
So in other words, the Slashdot writeup that stated this was a new format that was better than JPEG was completely incorrect, and in actual fact this is simply a container format that uses existing JPEG algorithms? Sounds about usual for Slashdot these days.
According to the JPEG FAQ, PNG is more efficient than lossless JPEG for most images. Unfortunately, this specification doesn't allow for that; as far as I can tell this has little to do with picture qual
Re:Why? (Score:5, Informative)
This is not processing RAW into a TIFF - you can do that now with many tools. This is repackaging a RAW file into a new, universal RAW - this should open the RAW processor world to a new level of competition (as the greatest amount of R&D time was always wasted on reverse engineering RAW formats - something Adobe is now doing for you with DNG Converter).
Re:Why? (Score:5, Informative)
Re:Why? (Score:3, Interesting)
Re:Why? (Score:4, Informative)
Re:Why? (Score:3, Interesting)
Re:Why? (Score:3, Informative)
Re:Why? (Score:2, Interesting)
But could you clarify what makes PNG *not* good for photography? Also - isn't there some other format that might be better suited and is already present?
Re:Why? (Score:3, Informative)
Re:Why not lossless JPEG/JPEG2000 then? (Score:3, Informative)
the RAW images basically give you direct data off the sensor and all the data about the cameras current
Re:Why? (Score:5, Insightful)
Does this format offer anything that couldn't be done with PNG?
They key to this format is that it's in a format that's given off by the CCD and CMOS sensors, not in a processed colorspace of any kind (like RGB)
What really concerns me, however, is this:
which Adobe is making available for free
Is this a free-to-all? Or just free-to-camera-developers so we can force user to use photoshop or license from Adobe?
Re:Why? (Score:5, Insightful)
Looking at Adobe's history on postscript & pdf format I guess we should reasonably expect this new format's spec to be free (as beer) and usable by everyone
Re:Why? (Score:5, Informative)
A raw format file, while still storing all the data that has come off the image sensor, can be one third the size of a PNG because it knows that the first pixel has only red channel information, the second only green and so on.
Re:Why? (Score:5, Informative)
Couple of notes...
That chessboard layout is called a Color Filter Array, usually arranged in a Bayer Pattern. [dpreview.com]
Digital cameras these days are 10 bit in RAW mode.
And some even have 4 color sensors. [dpreview.com]
dpreview is THE site for camera buffs, much the same way avsforum is for us audio & vidio philes. Now if only I could find sites for other categories....
--
"Geometry is frozen music"
- Pythagoras
Re:Why? (Score:5, Informative)
DNG is about unifying the mess of "RAW" formats - camera-specific proprietary file formats containing raw dumps of unprocessed sensor information and shot metadata.
Furthermore, DNG is not immediately about getting camera manufacturers to use it themselves - though that would be the ideal. DNG is a bridge format - something you can convert all of your RAW files to for the purposes of long-term preservation/storage. It is open and documented, and based on TIFF so there are existing reader libraries that can handle the basic format (they will need extensions to do anything with it of course).
Adobe has provided DNG Converter which will enable anyone - even non-Adobe users - to benefit from the ongoing R&D Adobe does to support the variety of RAW formats out there. This will simplify the task of building quality RAW converters by allowing small developers to focus on excellent RAW processing and not have to exert to support the many camera RAW formats out there.
Sorry, I just woke up so I'm not going to touch on everything - but this is a major announcement whose importance will become more clear in time.
Re:Why? (Score:3, Insightful)
Maybe, but you appear to be more on top of things than all the people who didn't bother to do a shred of research before accusing Adobe of just inventing a new format for no other reason than to control the market. I wouldn't put that kind of tactic past them, but people should at least do some verification for their evil market domination theories....
Re:Why? (Score:3, Insightful)
Re:Why? (Score:4, Informative)
And, again, PNG is totally the wrong format for this. You'd be taking a huge hit upfront in terms of indexing -- or your images would be outrageously huge.
How DNG differs from TIFF, I don't know. I would have thought TIFF would be the obvious answer. (TIFF, for those who don't know, aren't compressed but can be losslessly compressed)
Re:Why? (Score:5, Informative)
First, PNG is not always indexed. However, it would have required massive extensions to PNG to turn it into something capable of being DNG, and TIFF is already well placed for extension (TIFF is a container format - most people think of it as a simple image format, but it is very flexible and capable of adaptation).
TIFF supports a huge variety of compression modes, including uncompressed, JPEG, LZW, and ZIP, and a variety of color modes.
DNG is an extension to TIFF, to allow the additional properties of a RAW to be expressed without losing the efficiencies of RAW (linear data, typically one color channel per pixel until processing). Just as a for instance - you can take your DNG into most any TIFF reader today and it will at the very least be able to read the preview embedded in the DNG without any mods to your TIFF library.
Re:Why? (Score:3, Informative)
Re:Why? (Score:3, Informative)
No, it is not [libpng.org]. It *can* do that, but PNG supports full 24-bit color, with 8 bit alpha. And possibly higher color depths if necessay (there's a byte or so in the header for bits-per-color).
Re:Why? (Score:5, Informative)
Plus, correct me if I'm wrong, but doesn't PNG assume all pixels have RGB information? Oftentimes this isn't the case in digital cameras (unless you're using a Foveon sensor). Google "Bayer Pattern" if you're interested.
The article is light on details, but I don't think Adobe is aiming this solely towards digital cameras (even expensive digital backs for medium-format cameras), but also towards medical imaging and what not. There is a reason why ImageMagick can be built with 24bits/channel and up.
Re:Why? (Score:3, Interesting)
Well, I would hope so, because otherwise it would be incredibly retarded. As the article says, "Raw photo files contain all the original information captured by a digital camera sensor before any in-camera processing occurs [...]" Many cameras have sensors with not just sensors for red, green, and blue, but also a fourth colour. PNG can possibly contain a fourth colour channel, but can it also save meta-information about that channel, which co
Re:Why? (Score:4, Informative)
Hell yes. Unlike with a raster image such as JPEG or PNG, the data from a camera sensor is most likely a Bayer array - alternating lines of Red/Green and Blue/Green sensors, rather than RGB triplets, so it's not so much RGB, as RGBG. (There are some varients/exceptions in the in sensors from Foveon, Fuji and Sony). There is also a lot of data specific to the exposure; duration, ISO, lens details, etc. which would need to be applied in camera before a raster image could be produced. With RAW, you can apply these settings after the event in Photoshop or whatever. Exposed the sky correctly, but got the ground off by a stop? No problem; "develop" the RAW twice and use the sky from one shot and the ground from the other for a much better result than "enhancing" the ground in an image editor.
Yes, you could have most of this with a tweaked version of PNG and a bunch of ID3 type tags (and maybe that's exactly what Adobe has done, I haven't looked at the file format yet). The main benefit though is to make it very easy for data exchange and solve the nightmare situation whereby each new sensor has it's own RAW format. The state of play at the moment is a nightmare for vendors like Adobe who need to update their software for almost every new high-end camera release. Likewise for the makers of those "digital photo stations" that are cropping up like Starbucks, or their little brethren; the printers you can plug a camera into directly. With a standard like DNG to support you gain the much larger colour gamut of the RAW format and more flexibility in tweaking the image for a better print.
Anyway, you can read the actual Adobe press release, or download a free (beer) DNG converter here [adobe.com] to find out a little more.
Re:Why? (Score:3, Informative)
When you shoot in JPEG and even in TIFF with any current camera the internal processor applies white balance, color, contrast, sharpening and other algorithms to the data and saves it in the chosen format, typically JPEG at anywhere from a 1:2 to 1:8 loss compression ratio.
This is great for point, click, print. But for hobbyist
Re:Me too. (Score:4, Interesting)
Re:Why? (Score:3, Interesting)
For that matter, why aren't we seeing J2k everywhere? It looks like a great format.
Re:what are the benefits? (Score:2)
Re:what are the benefits? (Score:3, Insightful)
Re:I fail to see... (Score:4, Insightful)
Yet it will be up to camera makers to support the specification, which Adobe is making available for free.
So it looks like they aren't charging for it. And if everyone can standardize on a single format, that'd make EVERYONE'S life a lot easier.
Re:Newsflash (Score:4, Funny)
Re:Newsflash (Score:5, Informative)
Actually no it's not useless, this would be very useful, especially if the format is open. Remember Adobe also cerated PDF - they know about making money from open standards.
You see proper digital cameras - especially the ones that cost $10,000 and are used by photojournalists and the like all let you save the image in raw format - that's a copy of the actual data that was captured before any processing. By doing so, you can take the image home and adjust it - white balance, satuaration and everything else - with photoshop et al. Rather than letting the camera make the adjustment and possibly messing things up, you know you still have the raw data so you can undo your changes. Trouble is, all the camera manufacturers ahev their own standard for raw data, so to get it into photoshop, the gimp or whatever you want to use, you must first run the raw image through software provided by your camera manufacturer - and you can bet that software won't run on Linux.
So this is good, 1 because it encourages interoperability and 2 because it further opens up proper image processing to Linux users.
Re:What does the "G" stand for? (Score:5, Funny)
Re:Obligatory Simpsons Ref... (Score:3, Funny)
Something about Soviet Russia, im not sure how it goes, but your mother was a whore.
do you know what you're talking about? (Score:5, Insightful)
How about you don't tell us photographers what we do/don't need?
We DO need a standard raw file format. Canon, Nikon, Fuji, Sigma, etc all have their own raw formats. This makes developing good raw-file handling software difficult, because you either have to dump lots of time into supporting several file formats, or settle for a small piece of the market and only support certain brands. It's also a royal pain in the ass for media companies who, to maintain some order in their workflow, "standardize" (fancy word for "get locked into") on one camera system maker.
Adobe is the defacto tool for processing digital images; nothing comes close. Knoll and his team have, after several years, picked up quite a bit of experience with what works and what doesn't; what customers need and what they don't, etc. Adobe's status puts them in the position to push a common raw format, and it's likely many of the companies that make decoders will add it in; it will be a case of software support before hardware support no doubt- but eventually camera makers will grumble a little and add it in. They've long since given up trying to make money off their raw format decoders.
Most media companies will no doubt be thrilled, because now they can handle Joe Shmoe's D4X raw file just like they handle Bob Smith's 1Ds Mark 3 raw file, save maybe for some image size differences.
By the way- RAW = Canon, NRF(I think?) = Nikon. Confusing that the style of file is called "raw" but Canon has a format called RAW. Please use capitalization to distinguish between the Canon format and the general style of compressed image.
Re:Anyone who uses JPEG... (Score:4, Informative)
photographs are usually TIFF documents, but we've ran accross many customers who supply all of their graphics and photos as high-res JPEGs
Adobe lockin v.s. Quark? you obviously don't work in a printing house. Quark is basicly the only tool used in creating anything for print. Quark can create Adobe PDF Files without issues from any other software we use.
Now that i think about it, most of the software we use is based on Open standards from Adobe (Postscript, DSC(Document Structuring Convention), PDF, PJTF, JDF)
YIDIWIP (Yes I Do Work In Prepress)
Re:What has not been said (Score:5, Informative)
Maybe that's because it's brand new and it's just been released.
Adobe in it's traditional greedyness did not release this as Open Source, they released a spec but not code. They just don;t get how to work with the open source community.
The way to work with the Open Source community to to release non-proprietary specifications for which we can write code ourselves. SO FAR they've done a pretty good job with PDF and DNG. What? Do you think no one is going to write an Open Source library for it?
Sheesh, talk about greedy; they could've colluded with camera manufacturers to monopolize on a closed, proprietary format, and you complain because they didn't give you the frickin' code? Get off your rear-end and write it yourself. That's the Open Source way.
PS: Adobe sucks for entirely different reasons (e.g. Dmitry Skylarov). This, however, is not one of those reasons. Adobe did right this time.
RTFA (Score:3, Informative)