18 Replies Latest reply on Oct 11, 2009 2:26 AM by l.clevy

    DNG Specification 1.3

    Royi A Level 1

      Hello.

      In the latest RC of ACR 5.4 a new Specification for the DNG format (1.3) is mentioned.

       

      Where can I read about it?

       

      Thanks.

        • 1. Re: DNG Specification 1.3
          Geoff the kiwi Adobe Community Professional & MVP

          I understand the documentation is not finished yet.

          • 2. Re: DNG Specification 1.3
            Royi A Level 1

            I see.

            Thanks.

             

            Hopefully they'll publish it soon.

             

            I hope there are some new exciting features (Losless Compression for instance).

            • 3. Re: DNG Specification 1.3
              MadManChan2000 Adobe Employee

              There are indeed some neat things in 1.3.

               

              However, lossless compression is already part of DNG 1.2 and earlier. Lossless compression can be turned on/off with the DNG Converter, and a number of cameras already support the creation of lossless-compressed DNG raw files.

              • 4. Re: DNG Specification 1.3
                Royi A Level 1

                Could you elaborate a little more about how Neat DNG v 1.3 is?

                 

                Thanks.

                • 5. Re: DNG Specification 1.3 and CR2 files
                  l.clevy

                  Hi,

                   

                  I'm converting CR2 files from the 50D with vignetting correction enabled (I suspect tags 0x4015 and 0x4016 involved in CR2), and using Camera Raw and DNG converter 5.4, there is no opcode FixVignetteRadial in the resulting DNG files.

                   

                  Is this opcode created from information in the CR2 file, or added by Photoshop when applying a vignetting correction ?

                   

                  Kind regards,

                   

                  Laurent

                  http://lclevy.free.fr/cr2

                  • 6. Re: DNG Specification 1.3
                    MadManChan2000 Adobe Employee

                    I'm converting CR2 files from the 50D with vignetting correction enabled (I

                    suspect tags 0x4015 and 0x4016 involved in CR2), and using Camera Raw and DNG

                    converter 5.4, there is no opcode FixVignetteRadial in the resulting DNG

                    files.

                     

                    Correct. ACR, LR, and DNG Converter do not parse the Canon vignette

                    correction metadata from the raw file, nor do they automatically create

                    FixVignetteRadial opcodes based on this metadata. It would be nice if they

                    did, but they do not.

                     

                     

                    Is this opcode created from information in the CR2 file, or added by Photoshop

                    when applying a vignetting correction ?

                     

                    Neither.

                     

                    (In fact, I am not aware of any publicly-available software at present that

                    creates FixVignetteRadial opcodes.)

                     

                    Eric

                    • 7. Re: DNG Specification 1.3
                      l.clevy Level 1

                      Thank Eric,

                       

                      I'm trying to understand the Canon Raw format v2 : http://lclevy.free.fr/cr2

                       

                      Do you know if the BlackDeltaV table (same size of the picture rows) is taken from the CR2 file or pre-configured for each camera model, like the CameraCalibration2 tag I suppose.

                       

                      More generally, I would like to know, in order to process a CR2, which information must be pre-configured and which information is embedded in the CR2 file. A part of the answer is which information is read from a CR2 to produce a DNG and which information is pre-configured.

                       

                      I'm pretty sure Vignetting, Chromatic Aberration, Geometric distortion and Color blur corrections are embedded in the CR2... but in which tags ?

                      Vignetting can be done in the camera and modified in DPP, Canon RAW processing software...

                       

                      Laurent

                      • 8. Re: DNG Specification 1.3
                        MadManChan2000 Adobe Employee

                        Laurent, unfortunately I don't have the full answers to your questions. My

                        understanding is that the black levels are fixed for some cameras, whereas

                        they are per-row or per-column variable for other models. Hence I don't have

                        a consistent answer that works across all Canon models.

                         

                        The main real information that we read from cameras' metadata is the as-shot

                        white balance. Occasionally we will also read other basic information, like

                        the final desired cropped image dimensions. Lens correction data, if it

                        exists, is almost always in the maker note and is not generally publicly

                        documented. I am not convinced that all of the lens correction metadata that

                        you list are actually embedded in .CR2 raw files; I cannot prove this either

                        way, however.

                         

                        Eric

                         

                         

                        I'm trying to understand the Canon Raw format v2 : http://lclevy.free.fr/cr2

                         

                        Do you know if the BlackDeltaV table (same size of the picture rows) is taken

                        from the CR2 file or pre-configured for each camera model, like the

                        CameraCalibration2 tag I suppose.

                         

                        More generally, I would like to know, in order to process a CR2, which

                        information must be pre-configured and which information is embedded in the

                        CR2 file. A part of the answer is which information is read from a CR2 to

                        produce a DNG and which information is pre-configured.

                         

                        I'm pretty sure Vignetting, Chromatic Aberration, Geometric distortion and

                        Color blur corrections are embedded in the CR2... but in which tags ?

                        Vignetting can be done in the camera and modified in DPP, Canon RAW processing

                        software...

                         

                        • 9. Re: DNG Specification 1.3
                          l.clevy Level 1

                          Thank you for your answer Eric,

                          did you have the chance to look at my document http://lclevy.free.fr/cr2 ?

                           

                          if yes, what is your opinion about it ? still incomplete, but for example to my knowledge, it is the first time the sRaw encoding is described publically.

                           

                          Kind regards,

                           

                          Laurent

                          • 10. Re: DNG Specification 1.3
                            MadManChan2000 Adobe Employee

                            Hi Laurent,

                             

                            Unfortunately I don't have time at the moment to examine the entire article.

                            I do think, however, that it is great that you are collecting the

                            information and documenting it. My main suggestion to you is simply to be

                            aware that in many cases the meaning of tags is model-specific, or sometimes

                            even changes subtly from one firmware revision to the next. Just FYI.

                             

                            Eric

                            • 11. Re: DNG Specification 1.3
                              l.clevy Level 1

                              thank you Eric for your suggestion.

                              yes, models specific tags are already what

                              Phil Harvey have seen and documented : http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/Canon.html , THE reference !

                               

                              the NEF format seems better designed on this point : http://lclevy.free.fr/nef/, http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/Nikon.html,

                              typically with the version number of each tag...

                               

                              I'm focusing on the RAW processing : documenting Dcraw ;-) and find the theory behind.

                               

                              CU

                               

                              Laurent

                              • 12. Re: DNG Specification 1.3
                                sandy_mc Level 3

                                Laurent,

                                 

                                Great work!!!

                                 

                                Think you may have left out one or two DNG tags, but its really great that you're documenting the Canon format. Go for it!!

                                 

                                Sandy

                                • 13. Re: DNG Specification 1.3
                                  l.clevy Level 1

                                  Sandy,

                                   

                                  thank you. It is still a draft and may contains some errors.

                                   

                                  which DNG tags do you suggest to add or remove ?

                                  My goal is only to talk about DNG only when it helps understanding CR2...

                                   

                                  Kind regards

                                   

                                  Laurent

                                  • 14. Re: DNG Specification 1.
                                    sandy_mc Level 3

                                    Laurent,

                                     

                                    No big deal - I had just noticed that you mentioned ColorMatrix2, but not ColorMatrix1 - it would be very unusual for a DNG file to have "2", but not "1"

                                     

                                    Regards,

                                     

                                    Sandy

                                    • 15. Re: DNG Specification 1.
                                      l.clevy Level 1

                                      Sammy,

                                       

                                      yes, you're right, I'm only describing ColorMatrix2 because the associated ColorIlluminant2 (D65) is used by dcraw to create DNG from CR2.

                                      did you have to go through the entire article and do you have suggestion / corrections ?

                                       

                                      Are you OK will the whole Color Space conversion part ?

                                       

                                      Regards,

                                       

                                      Laurent

                                      • 16. CR2 makernote, tag #4015
                                        l.clevy Level 1

                                        Hello,

                                         

                                        by comparing images content, I've found this :

                                         

                                        since 50D. for 50D and 5D Mark II.

                                        Offset Name Type Length Description
                                        0x0000tag versionshort10x1000 (0x1080 for the G11)
                                        0x0001tag lengthshort1116 (66 for G11)
                                        0x0004Correction appliedshort11=yes, 0=no
                                        0x000cDPP correction valueshort1
                                        0x0014flags?short10x125c for 500D and the 50D, 0x10cc for 7D, 0x1900 for 5D Mark II, 0x7ee for G11
                                        0x0016ImageWidthshort14752 for 500D and 50D, 5184 for 7D, 5616 for 5D Mark II, 3648 for G11
                                        0x0018ImageHeightshort13168 for 500D and 50D, 3456 for 7D, 3744 for 5D Mark II, 3648 for G11
                                        0x0028Lenses related databytes?10
                                        EF  85mm f/1.2 L II USM        = 70 04 DF 08 92 0C CA 0E FF 0F 
                                        EF  17-40 f/4.0 L USM          = 70 04 DF 08 92 0C CA 0E FF 0F
                                        EF  24-105mm f/4.0 L IS USM    = 70 04 DF 08 92 0C 0C 0E FF 0F (on 50D, APS-C)
                                                                         70 04 DF 08 92 0C 0C 0E FF 0F (on 5D MarkII)
                                        EF  70-300 f/4.0-5.6 IS USM    = 70 04 DF 08 92 0C CA 0E FF 0F
                                        EF 28-105mm f/3.5-4.5 USM      = 70 04 22 08 D4 0B 4F 0D FF 0F
                                        EF 24-70 L f/2.8 USM           = 70 04 DF 08 92 0C CA 0E FF 0F
                                        EFS 15-85mm f/3.5-5.6 IS USM   = B2 03 EA 05 65 07 22 08 1A 0A
                                        EFS 18-55 f/3.5-5.6 IS         = B2 03 EA 05 65 07 DF 08 1A 0A
                                        EFS 18-200 f/3.5-5.6 IS        = F5 02 65 07 DF 08 9D 09 1A 0A
                                        EFS 17-85 f/4/5.6 IS USM       = B2 03 EA 05 22 08 DF 08 1A 0A
                                        0x001a?bytes?12aperture and focal dependent. NOT time value depend.

                                         

                                        any ideas about the lens data and aperture/focal interpretation ?

                                         

                                        Laurent (http://lclevy.free.fr/cr2/)

                                        • 17. Re: CR2 makernote, tag #4015
                                          S4ENO Level 1

                                          Have you tried ExifTool and the documentation found there?

                                          • 18. Re: CR2 makernote, tag #4015
                                            l.clevy Level 1

                                            Yes, of course.

                                            and more than reading the doc, I've sent contributions to Phil Harvey (Exiftool author) about vignetting correction (see ExifTool history : v7.87 and v7.95 ).

                                             

                                            Laurent (http://lclevy.free.fr/cr2)