Missing exif information

Submitted by Twz93 on

Hi there,

I am using mostly libraw to convert IIQ to tiff and I did notice that some EXIF information such as the GPS coordinates and some various metadata related to the camera itself were missing after the conversion. It there any way to avoid this?

Thanks in advance.

Greg

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Assuming, you're using LibRaw

Submitted by lexa on

Assuming, you're using LibRaw's dcraw_emu sample, not some other app that uses LibRaw:

LibRaw's own TIFF writer routine is very simple, it is used to not depend on additional libraries (e.g. libtiff). So only minimal EXIF data is recorded into output.

LibRaw is opensource, we're open to user contribution. So feel free to implement own TIFF writer (w/ extensive EXIF recording) we will be happy to add it to LibRaw (if you wish so).

-- Alex Tutubalin @LibRaw LLC

Followup: we do not have any

Submitted by lexa on

Followup: we do not have any IIQ files w/ embedded GPS data. Could you please share some samples with us?

-- Alex Tutubalin @LibRaw LLC

Thank you for the file. In

Submitted by lexa on

Thank you for the file. In this file
- GPS coordinates are recorded in XMP block, not in GPSDirectory EXIF block
- GPSDirectory does not contains coordinates, only references:
| + [GPS directory with 3 entries]
| | 0) GPSVersionID = 2 3 0 0
| | - Tag 0x0000 (4 bytes, int8u[4]):
| | 6218624: 02 03 00 00 [....]
| | 1) GPSLatitudeRef = S
| | - Tag 0x0001 (2 bytes, string[2]):
| | 6218630: 53 00 [S.]
| | 2) GPSLongitudeRef = E
| | - Tag 0x0003 (2 bytes, string[2]):
| | 621863c: 45 00 [E.]

LibRaw does not parse XMP blocks (and no plans for that), so it is unable to extract GPS data from such file.

-- Alex Tutubalin @LibRaw LLC

I think its because of the

Submitted by Twz93 on

I think its because of the exiftool. The original IIQ image metadata seems different. Do you know an easy way to tell if its in the exif or xmp ? I will ask my coworker to see if we can create a IIQ with gps and no sensitive info but it may take several days.

I just sent you a link to the

Submitted by Twz93 on

I just sent you a link to the above address. The image was taken directly from the camera this time so it was not modified by exiftool.

Thank you for the sample.

Submitted by lexa on

Thank you for the sample.
In this sample:
- there is no EXIF/GPS records
- all location information is contained in XMP block

So, LibRaw does not read it

-- Alex Tutubalin @LibRaw LLC