dcraw and libraw mangles image metadata

I first ran into this issue using dcraw and then found libraw but they both seem to have the same problems; at least using the dcraw_emu executable.

metadata from libimage-exiftool-perl

DNG image metadata

ExifTool Version Number         : 11.88
File Name                       : IMG_0999.DNG
Directory                       : xxx
File Size                       : 40 MB
File Modification Date/Time     : 2020:07:01 02:40:14+08:00
File Access Date/Time           : 2020:07:04 01:14:05+08:00
File Inode Change Date/Time     : 2020:07:01 02:40:14+08:00
File Permissions                : rwxr-xr-x
File Type                       : DNG
File Type Extension             : dng
MIME Type                       : image/x-adobe-dng
Exif Byte Order                 : Little-endian (Intel, II)
Make                            : Hasselblad
Camera Model Name               : L1D-20c
Orientation                     : Horizontal (normal)
Software                        : 10.00.11.04
Modify Date                     : 2020:06:30 16:02:39
Image Width                     : 5568
Image Height                    : 3648
Bits Per Sample                 : 16
Compression                     : Uncompressed
Photometric Interpretation      : Color Filter Array
Strip Offsets                   : 1041083
Samples Per Pixel               : 1
Rows Per Strip                  : 3648
Strip Byte Counts               : 40624128
Planar Configuration            : Chunky
CFA Repeat Pattern Dim          : 2 2
CFA Pattern 2                   : 0 1 1 2
CFA Plane Color                 : Red,Green,Blue
CFA Layout                      : Rectangular
Black Level Repeat Dim          : 2 2
Black Level                     : 4096 4092 4091 4096
White Level                     : 65535
Default Scale                   : 1 1
Default Crop Origin             : 4 4
Default Crop Size               : 5464 3640
Bayer Green Split               : 0
Anti Alias Strength             : 1
Best Quality Scale              : 1
Active Area                     : 0 96 3648 5568
Opcode List 3                   : GainMap, WarpRectilinear
Default User Crop               : 0 0 1 1
Subfile Type                    : Reduced-resolution image
Preview Image Start             : 75970
Preview Image Length            : 965113
Y Cb Cr Coefficients            : 0.299 0.587 0.114
Y Cb Cr Sub Sampling            : YCbCr4:2:0 (2 2)
Y Cb Cr Positioning             : Co-sited
Reference Black White           : 0 255 128 255 128 255
About                           : Meta Data
Format                          : image/dng
Absolute Altitude               : +254.35
Relative Altitude               : +120.20
Gimbal Roll Degree              : +0.00
Gimbal Yaw Degree               : +12.20
Gimbal Pitch Degree             : -90.00
Flight Roll Degree              : -4.90
Flight Yaw Degree               : +8.50
Flight Pitch Degree             : +4.50
Cam Reverse                     : 0
Gimbal Reverse                  : 0
Self Data                       : Self data
Version                         : 7.0
Has Settings                    : False
Has Crop                        : False
Already Applied                 : False
Exposure Time                   : 1/120
F Number                        : 4.0
Exposure Program                : Program AE
ISO                             : 100
Exif Version                    : 0230
Date/Time Original              : 2020:06:30 16:02:39
Create Date                     : 2020:06:30 16:02:39
Exposure Compensation           : 0
Max Aperture Value              : 2.8
Metering Mode                   : Center-weighted average
Light Source                    : Fluorescent
Flash                           : No Flash
Focal Length                    : 10.3 mm
File Source                     : Digital Camera
Scene Type                      : Directly photographed
Exposure Mode                   : Auto
White Balance                   : Auto
Digital Zoom Ratio              : 1
Focal Length In 35mm Format     : 28 mm
Scene Capture Type              : Standard
Gain Control                    : None
Contrast                        : Normal
Saturation                      : Normal
Sharpness                       : Normal
Serial Number                   : 0K8TFAA0020268
Lens Info                       : 28mm f/2.8-11
GPS Version ID                  : 2.3.0.0
GPS Latitude Ref                : North
GPS Longitude Ref               : East
GPS Altitude Ref                : Above Sea Level
DNG Version                     : 1.4.0.0
DNG Backward Version            : 1.3.0.0
Unique Camera Model             : Hasselblad L1D-20c
Color Matrix 1                  : 1.2385 -0.7159 -0.0657 -0.0982 1.0352 0.0721 0.0457 0.0241 0.7437
Color Matrix 2                  : 0.731 -0.2746 -0.0646 -0.2991 1.0847 0.2469 0.0163 0.0585 0.6324
Analog Balance                  : 1 1 1
As Shot Neutral                 : 0.356545961 1 0.5400843882
Baseline Exposure               : 0
Baseline Noise                  : 1
Baseline Sharpness              : 1
Linear Response Limit           : 1
Camera Serial Number            : 0K8TFAA0020268
Shadow Scale                    : 1
DNG Private Data                : (Binary data 19829 bytes, use -b option to extract)
Calibration Illuminant 1        : Standard Light A
Calibration Illuminant 2        : D65
Profile Name                    : Embedded
Profile Hue Sat Map Dims        : 18 6 1
Profile Hue Sat Map Data 1      : (Binary data 3408 bytes, use -b option to extract)
Profile Hue Sat Map Data 2      : (Binary data 3439 bytes, use -b option to extract)
Profile Embed Policy            : Allow Copying
Noise Profile                   : 8.108e-05 6e-08
Original Default Final Size     : 0 0
Original Best Quality Size      : 0 0
Original Default Crop Size      : 0 0
Aperture                        : 4.0
CFA Pattern                     : [Red,Green][Green,Blue]
Image Size                      : 5568x3648
Megapixels                      : 20.3
Preview Image                   : (Binary data 965113 bytes, use -b option to extract)
Scale Factor To 35 mm Equivalent: 2.7
Shutter Speed                   : 1/120
GPS Altitude                    : 254 m Above Sea Level
GPS Latitude                    : [redacted]
GPS Longitude                   : [redacted]
Circle Of Confusion             : 0.011 mm
Field Of View                   : 65.5 deg
Focal Length                    : 10.3 mm (35 mm equivalent: 28.0 mm)
GPS Position                    : [redacted]
Hyperfocal Distance             : 2.39 m
Light Value                     : 10.9

dcraw -T or libraw dcraw_emu -T

ExifTool Version Number         : 11.88
File Name                       : IMG_0999.tiff
Directory                       : [redacted]
File Size                       : 57 MB
File Modification Date/Time     : 2020:07:04 03:04:21+08:00
File Access Date/Time           : 2020:07:04 03:04:21+08:00
File Inode Change Date/Time     : 2020:07:04 03:04:21+08:00
File Permissions                : rw-rw-r--
File Type                       : TIFF
File Type Extension             : tif
MIME Type                       : image/tiff
Exif Byte Order                 : Little-endian (Intel, II)
Subfile Type                    : Full-resolution image
Image Width                     : 5472
Image Height                    : 3648
Bits Per Sample                 : 8 8 8
Compression                     : Uncompressed
Photometric Interpretation      : RGB
Image Description               : 
Make                            : Hasselblad
Camera Model Name               : L1D-20c
Strip Offsets                   : 1852
Samples Per Pixel               : 3
Rows Per Strip                  : 3648
Strip Byte Counts               : 59885568
X Resolution                    : 300
Y Resolution                    : 300
Planar Configuration            : Chunky
Resolution Unit                 : inches
Software                        : dcraw v9.28
Modify Date                     : 2020:06:30 16:02:39
Artist                          : 
Exposure Time                   : 1/120
F Number                        : 4.0
ISO                             : 100
Focal Length                    : 10.3 mm
Profile CMM Type                : 
Profile Version                 : 2.1.0
Profile Class                   : Display Device Profile
Color Space Data                : RGB
Profile Connection Space        : XYZ
Profile Date Time               : 0000:00:00 00:00:00
Profile File Signature          : acsp
Primary Platform                : Unknown ()
CMM Flags                       : Not Embedded, Independent
Device Manufacturer             : none
Device Model                    : 
Device Attributes               : Reflective, Glossy, Positive, Color
Rendering Intent                : Perceptual
Connection Space Illuminant     : 0.9642 1 0.82491
Profile Creator                 : 
Profile ID                      : 0
Profile Copyright               : auto-generated by dcraw
Profile Description             : sRGB
Media White Point               : 0.95045 1 1.08905
Media Black Point               : 0 0 0
Red Tone Reproduction Curve     : (Binary data 14 bytes, use -b option to extract)
Green Tone Reproduction Curve   : (Binary data 14 bytes, use -b option to extract)
Blue Tone Reproduction Curve    : (Binary data 14 bytes, use -b option to extract)
Red Matrix Column               : 0.43608 0.2225 0.01393
Green Matrix Column             : 0.38509 0.71689 0.09709
Blue Matrix Column              : 0.14305 0.06061 0.71402
GPS Version ID                  : 2.2.0.0
GPS Latitude Ref                : Unknown ()
GPS Longitude Ref               : Unknown ()
GPS Altitude Ref                : Above Sea Level
GPS Time Stamp                  : 00:00:00
GPS Map Datum                   : 
GPS Date Stamp                  : 
Aperture                        : 4.0
Image Size                      : 5472x3648
Megapixels                      : 20.0
Shutter Speed                   : 1/120
GPS Altitude                    : 254 m Above Sea Level
GPS Date/Time                   :  00:00:00Z
GPS Latitude                    : [redacted]
GPS Longitude                   : [redacted]
Focal Length                    : 10.3 mm
GPS Position                    : [redacted]
Light Value                     : 10.9

You can see the gps latitude and longitude ref returns unknown; can this be fixed?

Forums: 

Thank you for the quick

Thank you for the quick response; I downloaded compiled and ran the latest github version.

I had another question; the tiff version adds a property, this one in particular looks like the malformed gps info.
[+Primary Platform : Unknown ()]
Is that a normal property value

Also properties such as gimbal pitch, yaw, roll among others are removed.

--- RAW01	2020-07-04 16:29:18.567144467 +0800
+++ TIFF01	2020-07-04 16:29:26.662419543 +0800
@@ -1,138 +1,80 @@
 ExifTool Version Number         : 11.88
-File Name                       : IMG_0999.DNG
+File Name                       : IMG_0999.DNG.tiff
 Directory                       : .
-File Size                       : 40 MB
-File Modification Date/Time     : 2020:07:04 13:48:55+08:00
-File Access Date/Time           : 2020:07:04 13:48:55+08:00
-File Inode Change Date/Time     : 2020:07:04 13:48:55+08:00
-File Permissions                : rwxr-xr-x
-File Type                       : DNG
-File Type Extension             : dng
-MIME Type                       : image/x-adobe-dng
+File Size                       : 57 MB
+File Modification Date/Time     : 2020:07:04 16:26:51+08:00
+File Access Date/Time           : 2020:07:04 16:26:51+08:00
+File Inode Change Date/Time     : 2020:07:04 16:26:51+08:00
+File Permissions                : rw-rw-r--
+File Type                       : TIFF
+File Type Extension             : tif
+MIME Type                       : image/tiff
 Exif Byte Order                 : Little-endian (Intel, II)
-Make                            : Hasselblad
-Camera Model Name               : L1D-20c
-Orientation                     : Horizontal (normal)
-Software                        : 10.00.11.04
-Modify Date                     : 2020:06:30 16:02:39
-Image Width                     : 5568
+Subfile Type                    : Full-resolution image
+Image Width                     : 5472
 Image Height                    : 3648
-Bits Per Sample                 : 16
+Bits Per Sample                 : 8 8 8
 Compression                     : Uncompressed
-Photometric Interpretation      : Color Filter Array
-Strip Offsets                   : 1041083
-Samples Per Pixel               : 1
+Photometric Interpretation      : RGB
+Image Description               : 
+Make                            : Hasselblad
+Camera Model Name               : L1D-20c
+Strip Offsets                   : 1872
+Samples Per Pixel               : 3
 Rows Per Strip                  : 3648
-Strip Byte Counts               : 40624128
+Strip Byte Counts               : 59885568
+X Resolution                    : 300
+Y Resolution                    : 300
 Planar Configuration            : Chunky
-CFA Repeat Pattern Dim          : 2 2
-CFA Pattern 2                   : 0 1 1 2
-CFA Plane Color                 : Red,Green,Blue
-CFA Layout                      : Rectangular
-Black Level Repeat Dim          : 2 2
-Black Level                     : 4096 4092 4091 4096
-White Level                     : 65535
-Default Scale                   : 1 1
-Default Crop Origin             : 4 4
-Default Crop Size               : 5464 3640
-Bayer Green Split               : 0
-Anti Alias Strength             : 1
-Best Quality Scale              : 1
-Active Area                     : 0 96 3648 5568
-Opcode List 3                   : GainMap, WarpRectilinear
-Default User Crop               : 0 0 1 1
-Subfile Type                    : Reduced-resolution image
-Preview Image Start             : 75970
-Preview Image Length            : 965113
-Y Cb Cr Coefficients            : 0.299 0.587 0.114
-Y Cb Cr Sub Sampling            : YCbCr4:2:0 (2 2)
-Y Cb Cr Positioning             : Co-sited
-Reference Black White           : 0 255 128 255 128 255
-About                           : DJI Meta Data
-Format                          : image/dng
-Absolute Altitude               : +254.35
-Relative Altitude               : +120.20
-Gimbal Roll Degree              : +0.00
-Gimbal Yaw Degree               : +12.20
-Gimbal Pitch Degree             : -90.00
-Flight Roll Degree              : -4.90
-Flight Yaw Degree               : +8.50
-Flight Pitch Degree             : +4.50
-Cam Reverse                     : 0
-Gimbal Reverse                  : 0
-Self Data                       : DJI Self data
-Version                         : 7.0
-Has Settings                    : False
-Has Crop                        : False
-Already Applied                 : False
+Resolution Unit                 : inches
+Software                        : dcraw v9.26
+Modify Date                     : 2020:06:30 16:02:39
+Artist                          : 
 Exposure Time                   : 1/120
 F Number                        : 4.0
-Exposure Program                : Program AE
 ISO                             : 100
-Exif Version                    : 0230
-Date/Time Original              : 2020:06:30 16:02:39
-Create Date                     : 2020:06:30 16:02:39
-Exposure Compensation           : 0
-Max Aperture Value              : 2.8
-Metering Mode                   : Center-weighted average
-Light Source                    : Fluorescent
-Flash                           : No Flash
 Focal Length                    : 10.3 mm
-File Source                     : Digital Camera
-Scene Type                      : Directly photographed
-Exposure Mode                   : Auto
-White Balance                   : Auto
-Digital Zoom Ratio              : 1
-Focal Length In 35mm Format     : 28 mm
-Scene Capture Type              : Standard
-Gain Control                    : None
-Contrast                        : Normal
-Saturation                      : Normal
-Sharpness                       : Normal
-Serial Number                   : 0K8TFAA0020268
-Lens Info                       : 28mm f/2.8-11
-GPS Version ID                  : 2.3.0.0
+Profile CMM Type                : 
+Profile Version                 : 2.1.0
+Profile Class                   : Display Device Profile
+Color Space Data                : RGB
+Profile Connection Space        : XYZ
+Profile Date Time               : 0000:00:00 00:00:00
+Profile File Signature          : acsp
+Primary Platform                : Unknown ()
+CMM Flags                       : Not Embedded, Independent
+Device Manufacturer             : none
+Device Model                    : 
+Device Attributes               : Reflective, Glossy, Positive, Color
+Rendering Intent                : Perceptual
+Connection Space Illuminant     : 0.9642 1 0.82491
+Profile Creator                 : 
+Profile ID                      : 0
+Profile Copyright               : auto-generated by dcraw
+Profile Description             : sRGB gamma 2.222 toe slope 4.5
+Media White Point               : 0.95045 1 1.08905
+Media Black Point               : 0 0 0
+Red Tone Reproduction Curve     : (Binary data 14 bytes, use -b option to extract)
+Green Tone Reproduction Curve   : (Binary data 14 bytes, use -b option to extract)
+Blue Tone Reproduction Curve    : (Binary data 14 bytes, use -b option to extract)
+Red Matrix Column               : 0.43608 0.2225 0.01393
+Green Matrix Column             : 0.38509 0.71689 0.09709
+Blue Matrix Column              : 0.14305 0.06061 0.71402
+GPS Version ID                  : 2.2.0.0
 GPS Latitude Ref                : North
 GPS Longitude Ref               : East
 GPS Altitude Ref                : Above Sea Level
-DNG Version                     : 1.4.0.0
-DNG Backward Version            : 1.3.0.0
-Unique Camera Model             : Hasselblad L1D-20c
-Color Matrix 1                  : 1.2385 -0.7159 -0.0657 -0.0982 1.0352 0.0721 0.0457 0.0241 0.7437
-Color Matrix 2                  : 0.731 -0.2746 -0.0646 -0.2991 1.0847 0.2469 0.0163 0.0585 0.6324
-Analog Balance                  : 1 1 1
-As Shot Neutral                 : 0.356545961 1 0.5400843882
-Baseline Exposure               : 0
-Baseline Noise                  : 1
-Baseline Sharpness              : 1
-Linear Response Limit           : 1
-Camera Serial Number            : 0K8TFAA0020268
-Shadow Scale                    : 1
-DNG Private Data                : (Binary data 19829 bytes, use -b option to extract)
-Calibration Illuminant 1        : Standard Light A
-Calibration Illuminant 2        : D65
-Profile Name                    : Embedded
-Profile Hue Sat Map Dims        : 18 6 1
-Profile Hue Sat Map Data 1      : (Binary data 3408 bytes, use -b option to extract)
-Profile Hue Sat Map Data 2      : (Binary data 3439 bytes, use -b option to extract)
-Profile Embed Policy            : Allow Copying
-Noise Profile                   : 8.108e-05 6e-08
-Original Default Final Size     : 0 0
-Original Best Quality Size      : 0 0
-Original Default Crop Size      : 0 0
+GPS Time Stamp                  : 00:00:00
+GPS Map Datum                   : 
+GPS Date Stamp                  : 
 Aperture                        : 4.0
-CFA Pattern                     : [Red,Green][Green,Blue]
-Image Size                      : 5568x3648
-Megapixels                      : 20.3
-Preview Image                   : (Binary data 965113 bytes, use -b option to extract)
-Scale Factor To 35 mm Equivalent: 2.7
+Image Size                      : 5472x3648
+Megapixels                      : 20.0
 Shutter Speed                   : 1/120
 GPS Altitude                    : 254 m Above Sea Level
+GPS Date/Time                   :  00:00:00Z
 GPS Latitude                    : xxx
 GPS Longitude                   : xxx
-Circle Of Confusion             : 0.011 mm
-Field Of View                   : 65.5 deg
-Focal Length                    : 10.3 mm (35 mm equivalent: 28.0 mm)
+Focal Length                    : 10.3 mm
 GPS Position                    : xxx
-Hyperfocal Distance             : 2.39 m
 Light Value                     : 10.9

Should I give you a copy of this image to take a look at the fields that are removed?

not too convenient to look at

not too convenient to look at tags as a flat list.

In verbose output I see PrimaryPlatform set to four zeroes in ICC profile section.
I don’t think this is a big problem (unless some real software will complain about it).

-- Alex Tutubalin

apologies about the output, I

apologies about the output, I sent a sample DNG file through the contact link.

I am still getting errors when trying to open the .tiff files

TIFFFieldWithTag: Internal error, unknown tag 0xa406.
TIFFFieldWithTag: Internal error, unknown tag 0xa407.
TIFFFieldWithTag: Internal error, unknown tag 0xa408.
TIFFFieldWithTag: Internal error, unknown tag 0xa409.
TIFFFieldWithTag: Internal error, unknown tag 0xa40a.
TIFFFieldWithTag: Internal error, unknown tag 0xa40b.

I am using colmap; which uses freeimage to import supported files. DNG files are unsupported but TIFF's are.

I think those unknown() values trips up freeimage.

I just downloaded the sample

I just downloaded the sample image and the exif file; I ran the test and still get the same errors when I try to load the .tiff file.

I ran a exiftool -v and there were some warnings

[Warning = ValueConv GPSTimeStamp: Argument "undef" isn't numeric in addition (+)]

  ExifToolVersion = 11.88
  FileName = DJI_0325.tiff
  Directory = images
  FileSize = 59887440
  FileModifyDate = 1593857589
  FileAccessDate = 1593857589
  FileInodeChangeDate = 1593857595
  FilePermissions = 33204
  FileType = TIFF
  FileTypeExtension = TIF
  MIMEType = image/tiff
  ExifByteOrder = II
  + [IFD0 directory with 23 entries]
  | 0)  SubfileType = 0
  | 1)  ImageWidth = 5472
  | 2)  ImageHeight = 3648
  | 3)  BitsPerSample = 8 8 8
  | 4)  Compression = 1
  | 5)  PhotometricInterpretation = 2
  | 6)  ImageDescription = 
  | 7)  Make = Hasselblad
  | 8)  Model = L1D-20c
  | 9)  StripOffsets = 1872
  | 10) SamplesPerPixel = 3
  | 11) RowsPerStrip = 3648
  | 12) StripByteCounts = 59885568
  | 13) XResolution = 300 (300/1)
  | 14) YResolution = 300 (300/1)
  | 15) PlanarConfiguration = 1
  | 16) ResolutionUnit = 2
  | 17) Software = dcraw v9.26
  | 18) ModifyDate = 2020:02:15 14:41:53
  | 19) Artist = 
  | 20) ExifOffset (SubDirectory) -->
  | + [ExifIFD directory with 4 entries]
  | | 0)  ExposureTime = 0.005 (5000/1000000)
  | | 1)  FNumber = 5 (5000000/1000000)
  | | 2)  ISO = 100
  | | 3)  FocalLength = 10.26 (10260000/1000000)
  | 21) ICC_Profile (SubDirectory) -->
  | + [ICC_Profile directory with 10 entries, 496 bytes]
  | | ProfileHeader (SubDirectory) -->
  | | + [BinaryData directory, 128 bytes]
  | | | ProfileCMMType = 
  | | | ProfileVersion = 528
  | | | ProfileClass = mntr
  | | | ColorSpaceData = RGB 
  | | | ProfileConnectionSpace = XYZ 
  | | | ProfileDateTime = 0 0 0 0 0 0
  | | | ProfileFileSignature = acsp
  | | | PrimaryPlatform = 
  | | | CMMFlags = 0
  | | | DeviceManufacturer = none
  | | | DeviceModel = 
  | | | DeviceAttributes = 0 0
  | | | RenderingIntent = 0
  | | | ConnectionSpaceIlluminant = 0.9642 1 0.82491
  | | | ProfileCreator = 
  | | | ProfileID = 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  | | 0)  ProfileCopyright = auto-generated by dcraw
  | | 1)  ProfileDescription = sRGB gamma 2.222 toe slope 4.5
  | | 2)  MediaWhitePoint = 0.95045 1 1.08905
  | | 3)  MediaBlackPoint = 0 0 0
  | | 4)  RedTRC = curv...
  | | 5)  GreenTRC = curv...
  | | 6)  BlueTRC = curv...
  | | 7)  RedMatrixColumn = 0.43608 0.2225 0.01393
  | | 8)  GreenMatrixColumn = 0.38509 0.71689 0.09709
  | | 9)  BlueMatrixColumn = 0.14305 0.06061 0.71402
  | 22) GPSInfo (SubDirectory) -->
  | + [GPS directory with 10 entries]
  | | 0)  GPSVersionID = 2 2 0 0
  | | 1)  GPSLatitudeRef = N
  | | 2)  GPSLatitude = xxx
  | | 3)  GPSLongitudeRef = E
  | | 4)  GPSLongitude = xxx
  | | 5)  GPSAltitudeRef = 0
  | | 6)  GPSAltitude = 500 (500/1)
  | | 7)  GPSTimeStamp = undef undef undef (0/0 0/0 0/0)
  | | 8)  GPSMapDatum = 
  | | 9)  GPSDateStamp = 
  Warning = ValueConv GPSTimeStamp: Argument "undef" isn't numeric in addition (+)
  Warning = ValueConv GPSTimeStamp: Argument "undef" isn't numeric in addition (+)

There's no such errors in the raw file

  ExifToolVersion = 11.88
  FileName = DJI_0325.DNG
  Directory = /home/blubee/PICTURES
  FileSize = 41454818
  FileModifyDate = 1581748912
  FileAccessDate = 1581757918
  FileInodeChangeDate = 1581757918
  FilePermissions = 33279
  FileType = DNG
  FileTypeExtension = DNG
  MIMEType = image/x-adobe-dng
  ExifByteOrder = II
  + [IFD0 directory with 43 entries]
  | 0)  SubfileType = 1
  | 1)  ImageWidth = 160
  | 2)  ImageHeight = 112
  | 3)  BitsPerSample = 8 8 8
  | 4)  Compression = 7
  | 5)  PhotometricInterpretation = 6
  | 6)  Make = Hasselblad
  | 7)  Model = L1D-20c
  | 8)  PreviewImageStart = 45450
  | 9)  Orientation = 1
  | 10) SamplesPerPixel = 3
  | 11) PreviewImageLength = 29218
  | 12) Software = 10.00.11.04
  | 13) ModifyDate = 2020:02:15 14:41:53
  | 14) SubIFD (SubDirectory) -->
  | + [SubIFD directory with 27 entries]
  | | 0)  SubfileType = 0
  | | 1)  ImageWidth = 5568
  | | 2)  ImageHeight = 3648
  | | 3)  BitsPerSample = 16
  | | 4)  Compression = 1
  | | 5)  PhotometricInterpretation = 32803
  | | 6)  StripOffsets = 830690
  | | 7)  SamplesPerPixel = 1
  | | 8)  RowsPerStrip = 3648
  | | 9)  StripByteCounts = 40624128
  | | 10) PlanarConfiguration = 1
  | | 11) CFARepeatPatternDim = 2 2
  | | 12) CFAPattern2 = 0 1 1 2
  | | 13) CFAPlaneColor = 0 1 2
  | | 14) CFALayout = 1
  | | 15) BlackLevelRepeatDim = 2 2
  | | 16) BlackLevel = 4096 4093 4093 4095 (4096/1 4093/1 4093/1 4095/1)
  | | 17) WhiteLevel = 65535
  | | 18) DefaultScale = 1 1 (1/1 1/1)
  | | 19) DefaultCropOrigin = 4 4 (4/1 4/1)
  | | 20) DefaultCropSize = 5464 3640 (5464/1 3640/1)
  | | 21) BayerGreenSplit = 0
  | | 22) AntiAliasStrength = 1 (100/100)
  | | 23) BestQualityScale = 1 (1/1)
  | | 24) ActiveArea = 0 96 3648 5568
  | | 25) OpcodeList3 = ....0L.@.`...  ?..!.B..?..!.B...@)..@.K.@..r@...@..\@.a@...?...[snip]
  | | 26) DefaultUserCrop = 0 0 1 1 (0/1 0/1 1/1 1/1)
  | + [SubIFD1 directory with 15 entries]
  | | 0)  SubfileType = 1
  | | 1)  ImageWidth = 960
  | | 2)  ImageHeight = 640
  | | 3)  BitsPerSample = 8 8 8
  | | 4)  Compression = 7
  | | 5)  PhotometricInterpretation = 6
  | | 6)  PreviewImageStart = 74668
  | | 7)  SamplesPerPixel = 3
  | | 8)  RowsPerStrip = 640
  | | 9)  PreviewImageLength = 756022
  | | 10) PlanarConfiguration = 1
  | | 11) YCbCrCoefficients = 0.299 0.587 0.114 (299/1000 587/1000 114/1000)
  | | 12) YCbCrSubSampling = 2 2
  | | 13) YCbCrPositioning = 2
  | | 14) ReferenceBlackWhite = 0 255 128 255 128 255 (0/1 255/1 128/1 255/1 128/1 255/1)
  | 15) ApplicationNotes (SubDirectory) -->
  | + [XMP directory, 8192 bytes]
  | | About = DJI Meta Data
  | | ModifyDate = 2017-09-14
  | | CreateDate = 2017-09-14
  | | Make = DJI
  | | Model = Test_Pro
  | | Format = image/dng
  | | GPSLatitude = xxx
  | | GPSLongitude = xxx
  | | AbsoluteAltitude = +500.17
  | | RelativeAltitude = +199.90
  | | GimbalRollDegree = +0.00
  | | GimbalYawDegree = -128.70
  | | GimbalPitchDegree = -89.90
  | | FlightRollDegree = +3.10
  | | FlightYawDegree = -89.90
  | | FlightPitchDegree = -7.00
  | | CamReverse = 0
  | | GimbalReverse = 0
  | | SelfData = DJI Self data
  | | Version = 7.0
  | | HasSettings = False
  | | HasCrop = False
  | | AlreadyApplied = False
  | 16) ExifOffset (SubDirectory) -->
  | + [ExifIFD directory with 26 entries]
  | | 0)  ExposureTime = 0.005 (1/200)
  | | 1)  FNumber = 5 (500/100)
  | | 2)  ExposureProgram = 2
  | | 3)  ISO = 100
  | | 4)  ExifVersion = 0230
  | | 5)  DateTimeOriginal = 2020:02:15 14:41:53
  | | 6)  CreateDate = 2020:02:15 14:41:53
  | | 7)  ExposureCompensation = 0 (0/10)
  | | 8)  MaxApertureValue = 2.971 (2971/1000)
  | | 9)  MeteringMode = 2
  | | 10) LightSource = 1
  | | 11) Flash = 0
  | | 12) FocalLength = 10.26 (10260/1000)
  | | 13) FileSource = 3
  | | 14) SceneType = 1
  | | 15) ExposureMode = 0
  | | 16) WhiteBalance = 0
  | | 17) DigitalZoomRatio = 1 (1/1)
  | | 18) FocalLengthIn35mmFormat = 28
  | | 19) SceneCaptureType = 0
  | | 20) GainControl = 0
  | | 21) Contrast = 0
  | | 22) Saturation = 0
  | | 23) Sharpness = 0
  | | 24) SerialNumber = 0K8TFAA0020268
  | | 25) LensInfo = 28 28 2.8 11 (280/10 280/10 280/100 1100/100)
  | 17) GPSInfo (SubDirectory) -->
  | + [GPS directory with 7 entries]
  | | 0)  GPSVersionID = 2 3 0 0
  | | 1)  GPSLatitudeRef = N
  | | 2)  GPSLatitude = xxx
  | | 3)  GPSLongitudeRef = E
  | | 4)  GPSLongitude = xxx
  | | 5)  GPSAltitudeRef = 0
  | | 6)  GPSAltitude = 500 (500/1)
  | 18) DNGVersion = 1 4 0 0
  | 19) DNGBackwardVersion = 1 3 0 0
  | 20) UniqueCameraModel = Hasselblad L1D-20c
  | 21) ColorMatrix1 = 1.2385 -0.7159 -0.0657 -0.0982 1.0352 0.0721 0.0457 0.0241 0.743[snip]
  | 22) ColorMatrix2 = 0.731 -0.2746 -0.0646 -0.2991 1.0847 0.2469 0.0163 0.0585 0.6324[snip]
  | 23) AnalogBalance = 1 1 1 (1000000/1000000 1000000/1000000 1000000/1000000)
  | 24) AsShotNeutral = 0.3372859025 1 0.6052009456 (256/759 256/256 256/423)
  | 25) BaselineExposure = 0 (0/100)
  | 26) BaselineNoise = 1 (100/100)
  | 27) BaselineSharpness = 1 (100/100)
  | 28) LinearResponseLimit = 1 (100/100)
  | 29) CameraSerialNumber = 0K8TFAA0020268
  | 30) ShadowScale = 1 (1/1)
  | 31) DNGPrivateData = [ae_dbg_info:.....d...dd. ....&^.....j.c.....7.......>.][ae_hi[snip]
  | 32) CalibrationIlluminant1 = 17
  | 33) CalibrationIlluminant2 = 21
  | 34) ProfileName = Embedded
  | 35) ProfileHueSatMapDims = 18 6 1
  | 36) ProfileHueSatMapData1 = 0 1 1 0.538309991359711 1.08341300487518 1 0.4128620028[snip]
  | 37) ProfileHueSatMapData2 = 0 1 1 -0.644068002700806 1.12516498565674 1 -1.43428194[snip]
  | 38) ProfileEmbedPolicy = 0
  | 39) NoiseProfile = 8.108e-05 6e-08
  | 40) OriginalDefaultFinalSize = 0 0
  | 41) OriginalBestQualitySize = 0 0
  | 42) OriginalDefaultCropSize = 0 0

Sorry, missed these notices

Sorry, missed these notices because of *very long* reply:

>> Also properties such as gimbal pitch, yaw, roll among others are removed.
>>Should I give you a copy of this image to take a look at the fields that are removed?

LibRaw::write_tiff_ppm() used in dcraw_emu creates very minimal set of EXIF tags.
There is no plans to extend this.

-- Alex Tutubalin

Apologies for the long

Apologies for the long response.

Do you have a program that can just convert the dng file to tiff without changing any of the dng's exif metadata?

There is no such program in

There is no such program in LibRaw 'sample code' programs.

One could implement such program using LibRaw or Adobe DNG sdk for raw (dng) decode and something like libtiff for tiff write.

-- Alex Tutubalin