DNG problem, is there a solution ?

[Katamara]

Hello.

0.79
Linux Sid Debian 64bit
XnViewMP

Regarding small Adobe .dng thumbnail;

Could it be possible to either regenerate or other to achieve a regular sized/quality
thumbnail from an Adobe .dng file ?

Thank you.

[XnTriq]

Hi Katamara

Did you activate Create from original image if embedded thumbnail is smaller than thumbnail size (Tools » Settings... » Thumbnail » Misc)?

[Katamara]

XnTriq.

Yes, thank you.

System: Debian Sid 64 bit

Objective: Trying to produce thumbnails from .dng files that relect the true .dng

I've tried;
1. Settings changed per your suggestion in XnViewMP;
2. XnViewMP 'Before' rebuild thumbnails: Example 1
3. XnViewMP 'After' rebuild thumbnails: Example 2
4. Program 'RawTherapee' default profile, reduce image to 320 pixels wide, save: Example 3

Problem is...
XnView is displaying an almost correct thumbnail now, but when clicked on, it displays the embedded 'incorrect'
.dng thumbnail (Example 1) in Preview, or extract/rebuild one to save ?

Is it possible to regenerate the thumbnail inside the DNG ?

Thank you.

[XnTriq]

XnView is displaying an almost correct thumbnail now, but when clicked on, it displays the embedded 'incorrect' .dng thumbnail (Example 1) in Preview, or extract/rebuild one to save ?

Please take a look at these settings (if you haven't already done so):

• Viewer » File » Format settings... » Read » Camera RAW
• Viewer/Browser » Tools » Settings... » General » ICC

Is it possible to regenerate the thumbnail inside the DNG ?

As far as I know, EXIF thumbnail - Rebuild (Browser » Tools » Metadata) only works for JPEGs.

[Katamara]

Are your settings from XnView or XnViewMP ?
I couldn't follow exactly with XnViewMP 0.79.

I'm using the below settings (MismatchedThumbs.02.png)
They are producing the correct rendering of the .dng image.

The problem is, the correctly rendered thumbnail (on right) is not what is
displayed on the left preview (MismatchedThumbs.jpg)

Thank you.

[XnTriq]

Are your settings from XnView or XnViewMP ?
I couldn't follow exactly with XnViewMP 0.79.

I'm using MP v0.79 on Windows, but the menu structure should be the same on Linux.
Please make sure to look for the Format settings in the File menu of MP's view mode.

Regenerating thumbnails inside DNGs:

Some choose to convert during ingestion (which we call early DNG binding). This requires awareness of a few issues and making decisions about how to handle these details during the rest of the workflow.

If you use Bridge/Camera Raw, PIE [Parametric Image Editing] work is automatically written to the DNG as XMP data. This makes your PIEwork portable since it is now contained within the DNG file. When the DNG is opened on another computer either in Bridge or Lightroom, the PIEwork will accompany the file. Bridge/Camera Raw gives you the option to update the JPEG previews immediately as you do your PIE work (Camera Raw Preferences: DNG File Handling). Although this insures that the JPEG previews are rebuilt to reflect your PIE work, this can slow your work progress unless you have a very fast workstation. We recommend that you don’t turn on this option; instead wait until you have finished adjusting your files. JPEG previews can be updated within Bridge or with the stand-alone DNG converter. We recommend that you run the newly adjusted DNG files back through the DNG converter since it can run in the background. If you open all the files in Camera Raw through Bridge to run the conversion, your workstation will be tied up until that task is finished.

An important item to be aware of is that you will need to save the new DNG files in a new folder, otherwise you will have a second copy of each DNG interleaved with the original files (i.e. the converter will add a _1 just before the file extension). This is true whether you use Bridge/Camera Raw, or the DNG converter.

When you add metadata to a DNG in Bridge, the DNG file is automatically updated with the new information, so that part’s easy. To update the embedded preview (or to convert the DNG to the newest version), go to the flyout menu in Camera Raw just under the Histogram and select “Update DNG Previews...”, as shown in Figure 13.

[Katamara]

XnTriq.

Thanks. You beat me to it.

I just discovered that one can update the preview image inside the original .dng image
with Adobe Bridge/Camera Raw.

I was hoping to 'not' touch the master original .dng images in any way.

I've recently been given thousands of .dng images from Smartphones, which have wildly
different ideas on how to produce a .dng image.

XnView is my only image viewer (it's the best), so I was surprised I couldn't view
the original .dng previews correctly. It's not XnViews' problem, understood.

I can't reprocess the originals to include a new preview image. It seems to be the only
way XnViewMP will function as needed for now.

Thank you for your assistance.

Best regards.

[XnTriq]

Thanks for reporting back, Katamara

Related topics (for future reference):

• DNG from Nokia Windows Phone
• Req: Embedded raw preview *if* available
• only viewing small DNG file

[Katamara]

For others frustrated by Smartphone's .dng/.jpg thumbail managing shortfalls...,

Adobe makes available a free DNG converter.

If you are comfortable with using this utility to 're save' your original .dng files that
have already been saved as .dng from the Smartphone...

Select the entire folder of original .dng images, save them to a new folder,
with the 'save preview' (medium or full sized) option checked.

I haven't fully investigated, but my thoughts are, if Adobe (creator of .dng) re saves a .dng
from an untouched original .dng... it should produce an identical copy exept
for the jpeg preview inside the .dng

Then... XnViewMP can accurately display the .dng thumbnail, and large preview image inside the .dng.
Below... the thumbnail on the Right, and the Preview image on the left inside the .dng are now correctly
displayed in XnViewMP.

Best of luck.

[XnTriq]

Glad to hear that you've found a solution/workaround, Katamara!

I haven't fully investigated, but my thoughts are, if Adobe (creator of .dng) re saves a .dng from an untouched original .dng... it should produce an identical copy exept for the jpeg preview inside the .dng

A while back, I used Compare It! to verify that XnView's Recreate EXIF thumbnail command “injects” an updated embedded thumbnail without modifying the rest of the test file.

• DiffNow
  “DiffNow lets you compare text files, documents, binary files, and archives up to 2048KB in size. You can either upload the files you wish to compare or enter their URLs. Results are returned as an interactive HTML report.”
• Visual Binary Diff
  “VBinDiff (Visual Binary Diff) displays files in hexadecimal and ASCII (or EBCDIC). It can also display two files at once, and highlight the differences between them. Unlike diff, it works well with large files (up to 4 GB).”
• TkDiff
  “TkDiff is a graphical front end to the diff program. It provides a side-by-side view of the differences between two files, along with several innovative features such as diff bookmarks and a graphical map of differences for quick navigation.”

[Katamara]

Sorry, been out of town.

A while back, I used Compare It! to verify that XnView's Recreate EXIF thumbnail command “injects” an updated embedded thumbnail without modifying the rest of the test file.

1. Did you inject into a 'Raw', e.g. .RAF (FujiFilm), .dng, or .jpg ?

Thanks for the follow up, helpful it is.
I use md5sum or shasum256 to compare files.

2. I've used XnViewMP 'Export' to save the embeded jpg in a raw file.
Is there a way to extract without re processing the embeded jpeg inside a raw or .dng file ?

Thank you again.

[XnTriq]

Hi again (=

1. Did you inject into a 'Raw', e.g. .RAF (FujiFilm), .dng, or .jpg ?

AFAIK, XnView can only do this for JPEGs.

I use md5sum or shasum256 to compare files.

The advantage of using a visual diff tool (overview bar) is that it tells you which parts are different and which are identical.

2. I've used XnViewMP 'Export' to save the embeded jpg in a raw file.
Is there a way to extract without re processing the embeded jpeg inside a raw or .dng file ?

• Adobe
  • Photoshop Lightroom: Extract preview for lost images
• Jeffrey Friedl
  • Lightroom Plugin: Extract Cached Image Previews
• Marc Rochkind
  • LRViewer
• Phil Harvey
  • ExifTool: Application Documentation » Reading Eamples
• FSoft
  • ERawP
• Calvin Hass
  • JPEGsnoop (Tools » Export JPEG…)
• Roman Orlov
  • deJpeg
• Gunamoi Software
  • ExtractJPEG
• Marco Pontello
  • BitmapRip
• CGSecurity
  • PhotoRec: Data Carving » Manual recovery of remaining JPEG

[Katamara]

XnTriq,

Thank you much for your excellent feedback and support.

XnViewMP was not on your list so I'm assuming it cannot extract without re processing.

Best regards.

[SOLVED]

[XnTriq]

XnViewMP was not on your list so I'm assuming it cannot extract without re processing.

As of version 0.80, XnViewMP isn't capable of extracting the JPEG losslessly. However, I encourage you to post a request in the “Suggestions” subforum.

PS: My previous post has been updated

[Katamara]

Suggestion posted.

Thanks for the links. Most are for Windows, some are old,
not developed anymore.

For other Linux users;
1. exiftool;
$ exiftool -b -PreviewImage -w %f.jpg DSC00267.ARW

2. exiv2;
$ exiv2 -ep2 DSC00267.ARW

3. ERawP;
Download binary with GUI

All extract extremely fast.

Cheers.