Errors processing EXIF data from jpgs


#1

Has anyone see errors in accessing the exif data in the jpg files? (see below). It occurs right after loading the images.

These are images captured by a Phantom 3 advance drone. I’m running on Windows with webODM/docker (using Docker for Windows) with the manual install. I tried removing and reinstalling the docker containers/images. Also did a ./webodm.sh rebuild but nothing fixed it.

Another person I’m working with on this project, who’s running on a mac with the standard webODM docker install isn’t getting these errors when using the same image files.

[DEBUG]   Loaded DJI_0017.JPG | camera: dji fc300s | dimensions: 1000 x 750 | focal: 3.6 | ccd: 6.16 | lat: 44.1519233333 | lon: -69.1492889445 | alt: 234.548
[DEBUG]   Loaded DJI_0055.JPG | camera: dji fc300s | dimensions: 1000 x 750 | focal: 3.6 | ccd: 6.16 | lat: 44.1496369722 | lon: -69.1509387222 | alt: 219.048
[INFO]    Found 108 usable images
Error: Directory (Last IFD item) with 19712 entries considered invalid; not read.
Error: Directory (Last IFD item): Next pointer is out of bounds; ignored.
Warning: Directory (Last IFD item), entry 0x0000 has unknown Exif (TIFF) type 1114; setting type size 1.
Error: Directory (Last IFD item), entry 0x0000 has invalid size 1145260365*1; skipping entry.
Warning: Directory (Last IFD item), entry 0x4d45 has unknown Exif (TIFF) type 17481; setting type size 1.
Error: Directory (Last IFD item), entry 0x4d45 has invalid size 1096565834*1; skipping entry.

#2

Hey @DaveSprague :hand: the errors are due to WebODM using a different library for resizing the images than what OpenDroneMap uses, so I’m guessing that the other person simply did not resize the images prior to processing and you did. The error is more of a “warning” and has no effect on the output dataset (the EXIF entries that we care about, lat/lon/altitude/focal length/sensor size are all read properly).

I agree that we might want to remove these “errors” at some point if they are not really “errors”. Could you open an issue on https://github.com/OpenDroneMap/WebODM/issues so that we can keep track of this?