Bug #41355 for Image-ExifTool: possible gps data parsing bugs: altitude and date/time

Mon Dec 01 15:05:46 2008 wolfgang.rupprecht [...] gmail.com - Ticket created

Subject:	possible gps data parsing bugs: altitude and date/time
Date:	Mon, 1 Dec 2008 12:05:08 -0800
To:	bug-Image-ExifTool [...] rt.cpan.org
From:	"Wolfgang Rupprecht" <wolfgang.rupprecht [...] gmail.com>

Not sure if this is a bug in the image generation or in exiftool's parsing. The error is still seen with Image-ExifTool-7.54 . Perl: This is perl, v5.10.0 built for x86_64-linux-thread-multi OS: Linux arbol.wsrcc.com 2.6.27.5-117.fc10.x86_64 #1 SMP Tue Nov 18 11:58:53 EST 2008 x86_64 x86_64 x86_64 GNU/Linux 1) the gps altitude displays as an unsigned number. This leads to the slightly amusing situation where small negative numbers (as happens at the sea shore) generate altitudes that show as 10 times the lunar orbital radius (~4 billion meters). This bug is observed on a 64-bit system. 2) the gps time and date display is totally wonky. I'm not sure what is going on here. The dates display as values between now and 50 years ago. The time is not any more accurate. I'll attach an unedited jpeg taken with an HTC G1 (google phone) where the phone geotagged the picture itself and I simply did a byte-for-byte copy off of the camera's flash card. (Apologies for the large attachment. I'd have put it in bugzilla, but it wouldn't let me file one without signing up for an acct. Signing up for one for every project I submit a bug report to is getting to be a real drag.) -wolfgang -- Wolfgang S. Rupprecht http://www.wsrcc.com/wolfgang/

Download pic20081130_155801.jpg
image/jpeg 620.3k

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Mon Dec 01 15:42:17 2008 EXIFTOOL [...] cpan.org - Correspondence added 5 min

Hi Wolfgang, Thanks for the bug report, but the problem is with the device that generated this image. On Mon Dec 01 15:05:46 2008, wolfgang.rupprecht@gmail.com wrote: Show quoted text

> 1) the gps altitude displays as an unsigned number.

It is stored as an unsigned 64-bit rational, which is incorrect. The fault lies with the software that wrote this value. Show quoted text

> 2) the gps time and date display is totally wonky. I'm not sure what > is going on here. The dates display as values between now and 50 > years ago. The time is not any more accurate.

Again, this is the image generator's problem. For both of these, you can see the raw values and their data types using the exiftool -v2 option (or -v3 to also see the binary data). The GPSDateStamp is a dead give-away, since this is stored in ASCII, and has a value of "1961:05:29\0". Show quoted text

> I'll attach an unedited jpeg taken with an HTC G1 (google phone) where > the phone geotagged the picture itself and I simply did a > byte-for-byte copy off of the camera's flash card.

The HTC firmware must be buggy. - Phil

Mon Dec 01 15:42:20 2008 The RT System itself - Status changed from 'new' to 'open'

Mon Dec 01 15:42:22 2008 EXIFTOOL [...] cpan.org - Given to EXIFTOOL

Mon Dec 01 16:49:26 2008 wolfgang.rupprecht [...] gmail.com - Correspondence added

Subject:	Re: [rt.cpan.org #41355] possible gps data parsing bugs: altitude and date/time
Date:	Mon, 1 Dec 2008 13:49:11 -0800
To:	bug-Image-ExifTool [...] rt.cpan.org
From:	"Wolfgang Rupprecht" <wolfgang.rupprecht [...] gmail.com>

Phil Harvey via RT writes: Show quoted text

> Thanks for the bug report, but the problem is with the device that > generated this image.

I was afraid of that. Thanks for the once over. I'm submitted this bug to the google android folks. -wolfgang

Tue Jan 06 11:08:00 2009 EXIFTOOL [...] cpan.org - Status changed from 'open' to 'rejected'