DNG compression

compressed seems to be the default when saving a DNG now. there is a check box for uncompressed but no description of whether the default it is lossless or lossy. there was a compression "lossless" check box in CS3. DNG spec says JPEG compression but mention both lossless and lossy. Does anyone have the straight scoop?
Thanks,
David

Thanks Vit.
The spec is vague on what type of jpeg compression is used
"Two Compression tag values are supported:
• Value = 1: Uncompressed data.
• Value = 7: JPEG compressed data, either baseline DCT JPEG, or lossless JPEG compression
If PhotometricInterpretation = 6 (YCbCr) and BitsPerSample = 8/8/8, or if PhotometricInterpretation = 1 (BlackIsZero) and BitsPerSample = 8, then the JPEG variant must be baseline DCT JPEG.
Otherwise, the JPEG variant must be lossless Huffman JPEG. For lossless JPEG, the internal width/length/components in the JPEG stream are not required to match the strip or tile's width/length/components. Only the total sample counts need to match. It is common for CFA images to be encoded with a different width, length or component count to allow the JPEG compression predictors to work across like colors."
It can be interpreted that lossy compression is used for the preview image but it is not clear.
David

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DNG compression on import

Hi,
I have NEF files with 24 MB. On one computer I have LR 2.3 with ACR 5.3. There, when I import and convert a file to DNG, it will be some 24 MB in size, because I chose in preferences not to compress. On another machine I have LR 2.4 with ACR 5.4, and the converted files here have some 12 MB. Of course, the "loss-less compression".
What makes me angry is that with this version of lightroom, I see no possibility to turn off compression. That means, LR is doing something that I am not happy with. I have been reading many posts about DNG compression, and I have the feeling there are things that we (the users) don't know.
I would like to keep my DNG files not compressed. Storage space is an issue of lesser importance for me, keeping the best possible file is of utmost importance. Even if they say compression is loss-less, I have the feeling it is only "almost" loss-less. Or else, why did they have in prior versions compressed and uncompressed?

Cosmo-
Compression is desired by many; others prefer to not compress, be it reasons of not being comfortable, or to pick up some tiny bit of speed. That's why there are choices. If you are concerned that your files are being diddled, perhaps you could leave them in RAW format?
Personally, I convert to DNG after culling and editing, not before, and I am fine with the lossless compression.

DNG Download from Leica M9 Camera

My LR3.3 on Win-7 is trying to download DNG compressed by Leica M9. Images are visible in grid view, but when I go to full size preview the message is "Preview not possible" or something similar.
Tried to download ACR6,4 but was informed this was not necessary. Then installed Adobe DNG converter v. 6.4 but response is the same.
Other problem is that LR3 is not presented as an AutoPlay option in Win-7..
Any help appreciated.

Sorry I was not clear. Just succeeded in LR3.3 under Win XP SP3, viewing DNG by Leica DMR. Import candidates are in grid view then previewed one prior to import in loupe view no prob. That is what failed in Win 7 with compressed DNG fm Leica M9 using SanDisk Ultra 8 GB SDHC.
Good news is that the aforesaid loupe preview has now succeeded with 2GB SD card. This, mind you, despite recommended use of SanDisk in the M9 manual. Thanks for your help.
Best, jwc
Sent from my iPhone

.NEF to .DNG conversion - why the weight loss?

What info is tossed when converting from .Nef > .DNG?
For example, I just converted a file and the Info says:
.NEF (15.6MB) > .DNG (10.9)
Is that one third drop in MB just Nikon encoding? Or is the image affected?

Try posting in the DNG forum. There are separate forums for DNG and for ACR.
http://forums.adobe.com/community/dng#
http://forums.adobe.com/community/cameraraw
(The answer is probably DNG compression; but let the pros there tell you.)

Benefit of DNG Lossy?

I just watched a free tutorial (well, several!) on Lynda.com regarding LR4 new DNG Fast and Lossy.
I understand that the Lossy DNG retains more information versus a jpeg. But if most of the world is using jpeg - exporting a Raw to Lossy will just finally result in converting to jpeg anyways, for print or posting on the web.
Benefits of Lossy, and how is it to be used in our workflow?
I never use DNG... now there is the DNG Fast... do many of you folks import your photos from Raw to DNG? Same benefits as working with Raw files?
the "DNG Fast allowing us to work 8X faster in the Develop Module" seems a compelling reason to experiment(!)
Thanks for your help

Up until now, DNG saved a little space on disk with its lossless compression, and it had the advantage of keeping XMP data internally instead of in a sidecar file. It also, in recent incarnations, keeps a checksum of image data, which allows easy computer checking of image corruption. Those are all relatively minor advantages.
The Fast Load data, if it works as advertised, is a compelling reason to convert all one's raw files to DNG. On that basis alone, I'll do it.
On a different thread, Eric Chan talks about lossy DNG compression. He claims that one of the ways it was tested was to create a lossy DNG and pass it and it's parent raw to Photoshop and see if people can tell which was which. Kind of a blindfold taste test. If you can't tell whether it was lossy-compressed or not, and it gives you the processing latitudes of a raw file, why not use it? The space savings are dramatic.
For somebody like me for whom an 8 x 10 print is big, lossy compression is a no-brainer except for 5-star images, of which I have maybe two.
Hal

Convert slide scan files to .dng?

We are scanning masses of old slide scans and bringing them into Lightroom as .tiffs. Recently I was told that if I convert those .tiff files to .dng that would enhance developing operations in the Develop module and almost simulate working with a RAW file.
Does anyone have any experience with this process? And any opinion about it?

The only advantage of DNG over a TIFF is its ability to retain the full RAW capture of a photographic sensor. A scanner works differently, some have a pseudo RAW format...Nikon scanners can do this scanning to the NEF format. But if you have scanned as a TIFF keep the original as a TIFF LR's functionality will be the same with a DNG made from a TIFF and the original TIFF. Whoever is telling you taht you can magically gain information by converting file types is misleading you and DNG compression (whilst the best for RAW formats, isn't any better than TIFF's so the file size remains the same as does the ability to write xmp metadata to the file (rather than as a sidecar file. In brief converting anything other than an original RAW file to the DNG format is just a waste of time.

Camera Raw Version 5.7 and Nikon D800E

Hi everyone, So with my new Nikon camera (D800E), I now realize that I can do nothing in CS4 with my RAW files. As my current version of Camera Raw is only 5.7 for it. Will I have to upgrade my version to at least CS5 with ACR 6.7 minimum? Maybe go with CS6? Regards, Jason Gaughan

The reason you can’t read the D800E raws in an old ACR plug-in is because that old ACR plug-in doesn’t know the camera parameters that are embedded in the raw converter. What the DNG Converter does is takes the original raw data and adds the Adobe-camera parameters and packages everything in a DNG file per the DNG standard. That DNG contains the raw data plus enough information for older ACR plug-ins to convert the data, as long as you set the compatibility options in the DNG Converter to create the DNG for that age of plug-in.
If you don’t delete your original files, then yes, the DNG Converter will create files that are also relatively similar in size to the NEFs, although they could be smaller or larger depending on what size of preview you embed an if the NEF compression is better than the DNG compression.
Lightroom is good. Check out the LR 5.2 update and run in 30-day trial mode to make sure it is compatible with your computer. http://www.adobe.com/downloads/updates/
You can always do Edit in Elements with LR Adjustments from within LR to get the file over into PSE for the final edits.

PSE12 slow loading Fujifilm files in slide show

I have just upgraded from PSE10 to PSE12 and now when I use the Slide show (full screen) in organizer with Fujifilm Raw files it take about a minute and a half to load up and same again when you zoom in. Is there any way of speeding this up in PSE12? It was slow in PSE10, but it did take over a minute in total.

nealeh wrote:
Thanks (I think). Duhhh - my head hurts .
To me also Reply #11 seemed key. But I think on first read through the significance of:
With the lossy compressed DNG (scene-referred), you can do all the normal edits you're accustomed to with raw: white balance, highlight recovery, changing camera color profiles, noise reduction, sharpening, lens corrections, etc. With the normal JPEG in DNG wrapper (output-referred), you cannot
had escaped me as it seems counter-intuitive - "lossy compressed" just sounds more image degrading than "normal".
The jpeg compression algorithm is generally used to compress image files like tiffs or psds. It is based on the fact that our eyes are much more sensitive to the luminosity than the colors, and that results in a 'simplification', not a 'degradation' of the data. Imagine you have a very detailed map of an island printed 1 meter x 1 meter. You want to print it 30 cm x 30 cm. You'll downsample the image so that you get a good 300 ppi picture : you simplify to discard all details your eyes could not see in the 30 x 30 print ; that is lossy in the sense that you discard the less meaningful bits of data.
Note that using the jpeg compression algorithm on the just demosaiced raw file is possible because you can process the luminosity and color information from that stage. At that stage, the 'jpeg' compressed data is still an undefined image unlike the usual output-referred jpegs. Another compression algorithm could have been used, with less visual efficiency.
Since the link I gave in this post, the new version of Lightroom has taken advantage of the lossy dng compression in a very smart way. Lightroom keeps a catalog and a preview file for quicker browsing on its library. Instead of using normal jpegs as previews, you can use lossy DNGs of about the same size. The advantage is that if the catalog and previews are stored in a computer and the library in another drive, you can edit the raw files and store the results in the catalog even if the other drive is not plugged in. When you plug the drive in, you can sync the parametric editing in the catalog to the real full size raw images.

Catalogue vs Browser conflict

I am trying to work how i can use LR for my processing, but allow the rest of my family to pick photos off windows explorer when they need a photo for something, like homework. I don't think it is realisitic to ask my children and wife to use LR although in theory I can put everythging on a network drive and everyone share it. However the catalogue approach menas the file they see in windows explorer or any other browser is the original and doesn't have any of the changes made to it. does anyone have any suggestions how to get round this? Options I have consdiered are:
1. Export all files I have edited as JPEGs to a seperate location. Solves the problem, but significantly increases storage as well as having to remember to do it!
2. Is there any function in LR to force an overwrite of the original file or that just not possible? Many of the the every day photos I take, like kids birthdays, get edited once and then that's it. I have no interest in keeping the originals. This would be great, but I haven't found it.
3. Is converting everything to DNG a possibilty? I know little about this. I tried exporting a RAW file as a DNG with a JPEG preview, but that doesn't show up in explorer which I thought it would. Am I missing something e.g. CODEC on my pc as my icons are just a Camera with PSD rather than an image? I tried exporting a 16Mb RAW file as compressed DNG and got one 10MB, then a 4MB JPEG and got 12MB!!!! Even if this works it seems to be creating a lot of extra storage for no particular reason. Is the RAW file smaller becuase the JPEG has to first be uncompressed and DNG compression isn't as aggressive?
Thanks for any advice. I have LR on free trial and really like it for my work flow, but already have irrate wife complaining!!1

With the latest version of Camera Raw PSE5 will automatically read the develop information added to the XMP sidecars for RAW files on import. There is a command "Edit/Update Thumbnails" in PSE5 that will update develop settings in PSE5 if need be by reading the XMP sidecars files changed in Lightroom or PSE Camera RAW. I have never tried it but I think it will do the same thing for develop settings embedded in non RAW files metadata. You can configure Lightroom in "Catalog Settings/Metadata/Include develop settings in metadata inside Jpeg, Tiff, and PSD files" and PSE should be able to read those files. However, only those with PSE5 or 6 and the proper Camera RAW will pick up those changes. You will need to export to a new file for things like sending them in email. There's no way to get around that.
I'll tell you what I would do in your situation. I would use a simpler application (Picasa or Vista/Windows Live Photo Gallery, for example) to manage my overall (those that don't need editing or that have been edited) files using keywords and would use Lightroom to manage and process RAW and those non RAW that need to be edited adding keywords only on export. It's not perfect, but there is no easy, simple way to do everything you want.

Camera Raw Version and Nikon D800E

Hi everyone,
So with my new Nikon camera (D800E), I now realize that I can do nothing in CS4 with my RAW files. As my current version of Camera Raw is only 5.7 for it. Will I have to upgrade my version to at least CS5 with ACR 6.7 minimum? Maybe go with CS6?
Regards,
Jason Gaughan

The reason you can’t read the D800E raws in an old ACR plug-in is because that old ACR plug-in doesn’t know the camera parameters that are embedded in the raw converter. What the DNG Converter does is takes the original raw data and adds the Adobe-camera parameters and packages everything in a DNG file per the DNG standard. That DNG contains the raw data plus enough information for older ACR plug-ins to convert the data, as long as you set the compatibility options in the DNG Converter to create the DNG for that age of plug-in.
If you don’t delete your original files, then yes, the DNG Converter will create files that are also relatively similar in size to the NEFs, although they could be smaller or larger depending on what size of preview you embed an if the NEF compression is better than the DNG compression.
Lightroom is good. Check out the LR 5.2 update and run in 30-day trial mode to make sure it is compatible with your computer. http://www.adobe.com/downloads/updates/
You can always do Edit in Elements with LR Adjustments from within LR to get the file over into PSE for the final edits.

Nikon D800 RAW file import

Hi,
Just got Lightroom 5 and cannot import RAW files.

You didn't re-save the NEFs in ViewNX2 did you?
The reason I ask is that there is a new feature to exclude preview when saving (in Capture NX2 anyway - dunno 'bout ViewNX2) - I guess Nikon got tired of people claiming DNG compression was better when the main reason DNGs may be smaller initially is due to the absence of (or smaller) jpeg preview .
Also, lots of people are using Lr5 with the D800 raws, but not a lot are using it with raws re-saved with the new ViewNX2.
Bottom line: try one fresh out of camera and see if that works. And if still no go, make sure you update your camera firmware.
Rob

Lossless compression of dng files like in Lightroom?

Lightroom losslessly compresses DNG files to half their size, which is wonderful. Is there any way to get Aperture to do this?

I remember seeing a plug-in to call the DNG converter from Aperture, but I think it never leaved the beta phase.
Anyway, using Adobe's converter is no big deal, and it's free.

Convert compressed MOS to DNG

Hi guys!
Does anybody know if there is a way to convert compressed *MOS files coming from Leaf Digital Back directly to DNG, avoiding Capture One?
Thanks!

Have you tried the Adobe DNG converter? I am not familiar with the Leaf back. But I would suspect that since there are a number of Leaf models that are supported by Camera Raw you should be able to use the DNG converter on those files as well. Here is a list of cameras that Camera Raw, Lightroom and the DNG converter support:
Camera Raw plug-in | Supported cameras

DNG native camera lossless compression on import

Hi. I have XP with LR2.5 and Ps CS4 and ACR 5.5. My camera (Leica M8) produces DNG files as its native format.
I am confused regarding methods to apply lossless compression to these DNG files. I have used this successfully previously but currently am unable to reproduce this function with LR2.
I have lossless compression for DNG set in preferences. I am importing the files from the card and applying a change to the file, for example WB, then selecting update metadata and preview as a workaround. However file sizes do not appear to change.
Since I have opened DNGs in another converter as well as in ACR too I am confused on where the lossless compression has been applied previously.
I have successfully applied this compression with ACR in the past but am trying to learn the LR workflow.
I am also unsure if I can have the lossless compression applied during import.
Any pointers as to what I am now missing would be greatly appreciated.

I don't think that in the workflow you describe there is any possibility for the data to become compressed by Lightroom. Updating metdata in a dng file does not touch the RAW data, so it is normal that the filesize does not change.
I am also unsure if I can have the lossless compression applied during import.
Any pointers as to what I am now missing would be greatly appreciated.
You can set the import pane up to "copy photos as dng". I believe this recompresses the dng but I have never owned a camera that uses dng as its native format so I am not sure about that. Otherwise, you can after import "Convert photo to DNG" from the edit menu. This should also reconvert files that are already dng.

I have converted some NEF files to DNG without compression but the conversion were performed WITH compression!

How to avoid it?
Bernard

As LR5user correctly notes, dng ALWAYS uses compression. You can only choose whether you want lossy compression or lossless compression. If you did not check the lossy compression checkbox, it will use a lossless algorithm. You do NOT want to avoid this as you are only wasting disk space if you don't use that compression. There is no loss of information. You should end up with files that are somewhat smaller than native raw files as the compression is somewhat more efficient than what camera makers use in their cameras in general.

DNG compression

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