GPS EXIF Picasa

[loganboyd]

So I used the GPS feature for the first time yesterday running v2.0.4

Here's my problem. If DL Pro adds the GPS data to the EXIF info for the photo, the main EXIF info such as shutter, aperture, focal length, camera model.... no longer show up in Picasa. I haven't tested with other similar programs.

The data does still show up in Adobe Bridge including the GPS info. My guess is that there is some problem with part of the EXIF data and as soon as Picasa sees that problem it just gives up and says... NOPE, there is no EXIF INFO where as programs like Adobe Bridge ignore the error for that EXIF Property and continue reading where it can.

I also downloaded an EXIF editor and opened a photo that Picasa said had NO EXIF DATA but Adobe Bridge could see it... I changed the Camera Make from CANON to CANOON and saved the image. After this change having the EXIF editor program update the EXIF info then Picasa showed me the EXIF info that I listed above.

What gives? any ideas? I'd like to be able to have the GPS info update when I download photos and then as I use Picasa to push those photos to PicasaWeb have the pictures show their location.

The problem may be that Picasa uses a different EXIF property to mark the Location Information.

I'm gonna mess with it some more, but just seeing if anyone else has noticed this.

thanks,
Logan

[loganboyd]

so i downloaded and ran the command line tool ExifTool
awesome tool btw!

here is the GPS info that is found once DL Pro has appended it to the exif data for the image

GPS Version ID : 2.0.0.0
GPS Latitude Ref : North
GPS Latitude : 39 deg 34' 23.54"
GPS Longitude Ref : West
GPS Longitude : 93 deg 2' 55.05"
GPS Altitude Ref : Above Sea Level
GPS Altitude : 192 m
GPS Map Datum : WGS-84
GPS Latitude : 39 deg 34' 23.54" N
GPS Longitude : 93 deg 2' 55.05" W
GPS Position : 39 deg 34' 23.54" N, 93 deg 2' 55.05" W

I'm starting to think that reason Picasa doesn't like the GPS info is the way that it is stated using non numeric characters such as the word "deg"

i used picasa to GeoTag a photo that had no GPS info in the EXIF and did a before and after comparison to the EXIF data and still found NO GPS EXIF data after Picasa had GeoTagged the image using Google Earth.
If I upload that image to my PicasaWeb page it will show the location and it does show this information on the webpage
Latitude: 39.648817° N
Longitude: 93.127857° W

I changed the data so you don't know EXACTLY where I am

time for lunch...
Logan

[DavidB]

If Bridge can read it, the chances are that the problem is with Picasa. The data which is failing to display is not normally contained in fields defined in the EXIF standard, but in MakerNotes defined (and often not well documented) by camera manufacturers. Adding the position data in what is a defined EXIF field may have exposed an error in the way Picasa reads the MakerNote for your camera, and perhaps others as well.

In post #4 in this thread, I outlined a couple of methods of checking IPTC data, which are equally applicable to EXIF, and which you may care to try. If EXIFTool in particular reads your data, Picasa is very likely to be the source of the problem.

Metadata is complex and often badly handled by image editors and browsers. One of the reasons I use Breeze products is that Chris seems to have taken a lot of care to comply with established metadata standards.

[loganboyd]

This one will be kind of long, so sorry about that.
Here's how I set up my test.
I took a jpg file off of my memory card by copying it using windows eplorer to my hard drive. I also downloaded that same file using DL Pro and having it insert GPS EXIF data. I then used Picasa to GeoTag the first file.
Now both files have GPS EXIF data.

I then took EXIFTool and exported ALL EXIF tags to a tab-delimited text file for both pictures.
I opened both text files side by side and removed all tags taht were NOT common to both files. Some get added by picasa and some get deleted... weird.

Here are the results of the 2 files with all common tags, notice how there are some differences in values such as Focal Length, Hyperfocal Distance
also the GSP Version ID is 2.0.0.0 from DL Pro and 0.0.2.2 from Picasa but the values are written out the same way.



Downloader Pro FILE
------------------
Aperture 2.8
Aperture Value 2.8
Bits Per Sample 8
Camera Model Name Canon PowerShot SD400
Canon 0x0000 0 0 0 0 0 0
Canon 0x0000 18 0 0 1 0 0 0 0 0
Canon 0x0013 0 0 0 0
Canon 0x0018 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0[...]
Canon 0x0019 1
Canon Firmware Version Firmware Version 1.01
Canon Flash Info 0 0 0 0
Canon Image Type IMG:PowerShot SD400 JPEG
Canon Model ID PowerShot SD400 / Digital IXUS 50 / IXY Digital 55
Circle Of Confusion 0.005 mm
Color Components 3
Color Space sRGB
Components Configuration YCbCr
Compressed Bits Per Pixel 5
Compression JPEG (old-style)
Create Date 2007:11:06 08:15:30
Custom Rendered Normal
Date Stamp Mode Off
Date/Time Original 2007:11:06 08:15:30
Digital Zoom Ratio 1
Directory \exif
Encoding Process "Baseline DCT, Huffman coding"
Exif Byte Order Little-endian (Intel)
Exif Image Length 1944
Exif Image Width 2592
Exif Version 220
ExifTool Version Number 7
Exposure Compensation 0
Exposure Mode Auto
Exposure Time 1/400
F Number 2.8
File Modification Date/Time 2007:11:06 08:15:30
File Name GPS-DLPro.JPG
File Number 127-2767
File Size 1717 kB
File Source Digital Camera
File Type JPEG
Firmware Revision 1.01 rev 2.00
Flash "Auto, Did not fire"
Flash Off
Flashpix Version 100
Focal Length 5.8mm
Focal Length 5.8mm (35mm equivalent: 34.4mm)
Focal Plane Resolution Unit inches
Focal Plane X Resolution 11520
Focal Plane Y Resolution 11571.42857
GPS Altitude 192 m
GPS Altitude Ref Above Sea Level
GPS Latitude "39 deg 31' 23.54"""
GPS Latitude "39 deg 31' 23.54"" N"
GPS Latitude Ref North
GPS Longitude "93 deg 3' 55.05"""
GPS Longitude "93 deg 3' 55.05"" W"
GPS Longitude Ref West
GPS Position "39 deg 31' 23.54"" N, 93 deg 3' 55.05"" W"
GPS Version ID 2.0.0.0
Hyperfocal Distance 2.37 m
Image Height 1944
Image Size 2592x1944
Image Width 2592
Interoperability Index R98 - DCF basic file (sRGB)
Interoperability Version 100
Make Canon
Max Aperture Value 2.8
Metering Mode Multi-segment
MIME Type image/jpeg
Modify Date 2007:11:06 08:15:30
Orientation Horizontal (normal)
Owner Name Bob Smith
Related Image Length 1944
Related Image Width 2592
Resolution Unit inches
Resolution Unit inches
Scale Factor To 35mm Equivalent 5.9
Scene Capture Type Standard
Sensing Method One-chip color area
Shutter Speed 1/400
Shutter Speed Value 1/403
Thumbnail Image "(Binary data 2957 bytes, use -b option to extract)"
Thumbnail Length 2957
Thumbnail Offset 5120
User Comment
White Balance Auto
X Resolution 180
X Resolution 180
Y Cb Cr Positioning Centered
Y Cb Cr Sub Sampling YCbCr4:2:2 (2 1)
Y Resolution 180
Y Resolution 180



Picasa GeoTagged File
-------------------
Aperture 2.8
Aperture Value 2.8
Bits Per Sample 8
Camera Model Name Canon PowerShot SD400
Canon 0x0000 1296 242 233 44 65303 0
Canon 0x0000 233 65303 0 233 65303 0 233 65491 65491
Canon 0x0013 0 26950 28018 24951
Canon 0x0018 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0[...]
Canon 0x0019 1
Canon Firmware Version
Canon Flash Info 0 0 0 1
Canon Image Type re Version 1.01
Canon Model ID PowerShot SD400 / Digital IXUS 50 / IXY Digital 55
Circle Of Confusion 0.005 mm
Color Components 3
Color Space sRGB
Components Configuration YCbCr
Compressed Bits Per Pixel 5
Compression JPEG (old-style)
Create Date 2007:11:06 08:15:30
Custom Rendered Normal
Date Stamp Mode Off
Date/Time Original 2007:11:06 08:15:30
Digital Zoom Ratio 1
Directory \exif
Encoding Process "Baseline DCT, Huffman coding"
Exif Byte Order Little-endian (Intel)
Exif Image Length 1944
Exif Image Width 2592
Exif Version 220
ExifTool Version Number 7
Exposure Compensation 0
Exposure Mode Auto
Exposure Time 1/400
F Number 2.8
File Modification Date/Time 2007:11:06 08:15:30
File Name GPS-Picasa.JPG
File Number 127-2767
File Size 1714 kB
File Source Digital Camera
File Type JPEG
Firmware Revision 1.01 rev 2.00
Flash "Auto, Did not fire"
Flash Off
Flashpix Version 100
Focal Length 5.8mm
Focal Length 5.8mm (35mm equivalent: 35.2mm)
Focal Plane Resolution Unit inches
Focal Plane X Resolution 11520
Focal Plane Y Resolution 11571.42857
GPS Altitude 0 m
GPS Altitude Ref Above Sea Level
GPS Latitude "39 deg 31' 19.76"""
GPS Latitude "39 deg 31' 19.76"" N"
GPS Latitude Ref North
GPS Longitude "93 deg 3' 4.54"""
GPS Longitude "93 deg 3' 4.54"" W"
GPS Longitude Ref West
GPS Position "39 deg 31' 19.76"" N, 93 deg 3' 4.54"" W"
GPS Version ID 0.0.2.2
Hyperfocal Distance 2.43 m
Image Height 1944
Image Size 2592x1944
Image Width 2592
Interoperability Index R98 - DCF basic file (sRGB)
Interoperability Version 100
Make Canon
Max Aperture Value 2.8
Metering Mode Multi-segment
MIME Type image/jpeg
Modify Date 2007:11:06 08:15:30
Orientation Horizontal (normal)
Owner Name
Related Image Length 1944
Related Image Width 2592
Resolution Unit inches
Resolution Unit inches
Scale Factor To 35mm Equivalent 6.1
Scene Capture Type Standard
Sensing Method One-chip color area
Shutter Speed 1/400
Shutter Speed Value 1/403
Thumbnail Image "(Binary data 2957 bytes, use -b option to extract)"
Thumbnail Length 2957
Thumbnail Offset 2604
User Comment
White Balance Auto
X Resolution 180
X Resolution 180
Y Cb Cr Positioning Centered
Y Cb Cr Sub Sampling YCbCr4:2:2 (2 1)
Y Resolution 180
Y Resolution 180

[DavidB]

Thanks for posting this interesting comparison. We're getting into territory where Chris is the real expert, and admit that I can get goggle-eyed trying to compare the two sets of data. However, it does appear to me that, whereas EXIFTool can read data in all the fields you list for the DL Pro file, it cannot read some of the corresponding data in the Picasa file.

This is a useful result, not only because Phil Harvey, the author of EXIFTool, is an acknowledged expert on image metadata, but also because his software is written quite independently of both DL Pro and Picasa.

In these circumstances, the first working hypothesis has to be that DL Pro is recording the data in the correct format and locations. The second hypothesis is that Picasa is either not recording the 'missing' data at all, or is recording it in incorrect locations in the image file structure. I understand that this is quite a common problem, particularly when the data resides in a Makernote.

All in all, I believe that your results are consistent with my original suggestion. But I'm at the limit of my knowledge, so it may well be that there is a better explanation of what you have discovered.

[loganboyd]

Thanks for all your comments

Yeah, EXIFTool lists a lot of ERROR/WARNINGS after Picasa has edited the file. I wish this stuff was more standardized and all big apps that touched the file respected and understood the layout of it.

Oh well, I guess I have bigger problems than this to worry about,

thanks again,
Logan

[DavidB]

Originally Posted by loganboyd

I wish this stuff was more standardized and all big apps that touched the file respected and understood the layout of it.

Amen to that.

[Chris Breeze]

DLPro sets the GPS Version Id to 2.0.0.0 using the byte order stored in the EXIF header (usually Intel alignment). The latest GPS IFD standard is 2.2 but there is no difference between 2.0 and 2.2 for the tags that DLPro uses and so I set it to the lower version to be compatible with older apps. The problem appears to be that Picassa incorrectly reads the GPS Version ID using Motorola alignment irrespective of the alignment specified in the EXIF header and reads it as 0.0.0.2, decides it is wrong and fails.

[ZackJones]

I take it from this discussion that DLP now writes GPS information to the EXIF header, is that correct? If so when did that feature come about? In the past I knew it would write the GPS information to an XMP sidecar. If DLP does write to EXIF header then I can stop tagging images using RoboGEO.

[DavidB]

The DL Pro Help page on GPS data begins with the following:

"Geo-tagging is the writing of geographical information in image files. Downloader Pro can automatically geo-tag JPEG and raw files by storing positional information in the form of latitude and longitude read from track log data from a GPS device. This information is written to the standard EXIF GPS shooting data stored in JPEG files and in the XMP sidecar file for raw files ..."

Looking at the Release Notes (also in Help), I think that the capability was introduced in Version 2.0, though some problems have been fixed in subsequent releases.

As to whether you can use DL Pro instead of RoboGEO, the best advice is to give it a try and see how you get on.