Carlsbad National Park

Last summer the boys took their Dad to see the “big trees” in northern California.  Dad enjoyed it so much that I planned another adventure for Christmas.  Because of other commitments, this adventure involved a lot of miles on the highways.  On Sunday we traveled from Albuquerque to Burleson, TX to drop off the kids with their cousins and pick up Dad.  Monday Dad and I drove to Carlsbad Caverns National Park, Tuesday we visited the cave, Wednesday we drove back to Burleson, and Thursday was the drive back to Albuquerque to be home for Christmas.

Ocotillo is a common plant in the Chihuahuan desert.

The weather cooperated,  the roads were clear; we had blue skies the whole distance, despite having snow the Friday before the trip.  On the East Mountain they got 2 feet of snow and I-40 was closed.  Fortunately by Sunday morning the snow was gone.

(As always, you can click on any photo in this blog to enlarge it.)

Road Trip Tech

The adventure at Carlsbad Caverns was enjoyed by myself and my Dad. We will continue to have adventures as long as we are both able.

A long road trip like this, with the better part of four days spent driving, goes better with the right technology along.  On this trip I tried out a new GPS navigator, listened to audio books, and experimented taking photos in the dark.

Garmin Nuvi 1350 GPS

Cholla cactus was blooming just in time for Christmas.

Garmin’s Nuvi line are automotive GPS units, designed for road trips as opposed to off-road use like most of their handheld cousins.  I had been using the Nuvi about town, but this was the longest road trip so far.  The Nuvi 1350 performed like a champ.  We were going to Ennis, TX first to drop off Abigail and Richard with their cousins.  (They did not want to see the cave.)  I had never been this route, usually going straight to Burleson.  The route to Ennis involved a number of exits and road changes in Fort Worth.  I almost missed one turn, but due to the Nuvi’s lane predictor I was in the correct lane to make the exit.  I’ve gotten lost in Fort Worth before, even when I know where I’m going, so making all the right turns on an unfamiliar route was great!

Jabra

Prickly Pear is a very common type of cactus in the Chihuahuan Desert.

We like to listen to audio books when traveling.  I had loaded up the MP3 files into my iPhone before departure.  The car setup is a mild Rube Goldberg production: Bluetooth from the iPhone to the Jabra hands-free device, then FM to the car radio, which plays the audio over the car stereo.  The Trailblazer has a nice Bose sound system, but it does not have an aux input so we have to go through the FM.  The FM spectrum in the Dallas-Fort Worth area is completely used up.  Eventually we were not able to find even one clear channel for the Jabra to use.  At one point we counted 16 radio towers visible simultaneously!

One of the more famous stalagmites in the Big Room at Carlsbad Caverns is the "Rock of Ages".

Fortunately Albuquerque is not so congested, and the system worked great on the open road.  If you live in or near a large city like Dallas-Fort Worth I would not recommend any hands-free device that plays over the car radio using FM.  It may be impossible to find a clear channel to use for the hands-free function.  Even on the road, it was necessary to change channels frequently, as it was often the case that the single FM station in a small town was broadcasting on the frequency we had chosen for the Jabra!

The Lion's Tail is a long formation that hangs from the ceiling of the Big Room over the path. There are several of these very unusual stalactites in this location.

The Jabra is primarily designed as a hands-free device for a mobile phone.  It clips to the sun visor and has its own speaker so it is not necessary to use the car audio system.

Manual Lens

Carlsbad Caverns is known for the many different types of formations found in the cave. Here tall, thin stalagmites seem to be reaching for the sky they will never see.

For the visit to Carlsbad I needed a fast lens to be able to shoot in the cave without a flash.  The park service has done a fantastic job with lighting the formations, but a flash will wash out the subtle colors and textures.  Also, the cave is so large that a flash will not illuminate the larger areas.  My old SLR was Ricky, a Ricoh XR7 that used Pentax K-mount lenses; Ricky passed away when his electronics failed, but I had kept his lenses and they fit Penny.  Ricky’s prime lens is a Rikkenon 50 mm f1.4.  With that lens I was able to practically shoot pictures in the dark!  (I did not even have a flash for many years.)

Curtains of stalactite formations beckon the visitor to come see ever more amazing sights.

Of course, the older f1.4 lens is completely manual.  I expected to have to focus manually, but I expected the camera to recognize the aperture setting on the lens.  However, the camera does not stop down the lens when shooting, so all photos are taken at f1.4 regardless of the aperture setting on the lens.  This is not a problem underground, where the lighting is dim enough that the lens has to be completely open, but could be an issue if I am shooting in brighter light and want more depth of field.  I’m still learning about all the features of Penny, my Pentax K20D whom I adopted off eBay, and there may be a way to get Penny to recognize the aperture setting on the Rikkenon lens.  I tried one shot with the built-in flash, but it came out all white, so either I can’t use flash with this manual lens, or I haven’t learned how to set it up.

The Big Room contains several massive stalagmites.

On my last visit to Carlsbad I used Ricky with his f1.4 lens and 400 speed film.  I hand held the camera.  Not the best, I know, but the slides turned out pretty well.  This time I brought a tripod.  I think it did help, but it was inconvenient to set up in the pathway.  With the fast lens and anti-shake technology, most of the pictures come out just find hand held.  Pentax incorporates their anti-shake in the camera body, not in the lens.  This gives even my old manual lenses anti-shake capability.

A more serious issue is that Penny lacks a split image focusing screen.  In the dim light I found it difficult to manually focus.  I found myself estimating the distance, setting it on the focus dial, and then bracketing the shot.  Fortunately on a DSLR I can see the results immediately, and it’s no problem to throw away the bad shots.  Can you imagine doing this with a film camera?  I wouldn’t even know the images were out of focus until I had paid for the developing!  I can see that the next improvement to Penny is going to be a split image focusing screen.  Maybe she’ll get a nice gift for her Adoption Day this summer!

Carlsbad Caverns National Park

Our day at the Caverns was split into three segments.  On the way in to the cave we took a short self-guided tour to an Indian shelter.  The big attraction was the Big Room in the cavern itself.  On the way out we took a side road through a Walnut Canyon.

The Indian Shelter

An interpretive trail led down to an alcove used by American Indians as a shelter from the hot sun.

An interpretive trail led down from the main road to an alcove that had in the past  been used by American Indians as a shelter during the day.  It is oriented in such a way as to provide shade from the hot sun during the day.  Interpretive signs along the short trail identified plants common to the Chihuahuan Desert.

This seasonal stream collects water from raistorms and channels it to a pool. The pool would have provided Native American people a pleasant diversion on hot summer days.

The Big Room

The Park Service uses various types of light sources to bring out the natural colors of the rocks. No colored lights are used.

We took our time on the self-guided Big Room tour.  I set up the tripod several times to take photos.  At the half-way point we took the shortcut back so Dad could use the restroom.  Then we walked back to see the far half of the Big Room.  All this walking got Dad tired out, and he was making liberal use of any benches along the path.  I noticed several park rangers were taking an interest in us, asking how we were doing.  I wondered why they were so concerned.  Though Dad was stopping to rest often, he did not look in distress, at least not to me.  The last ranger to ask about us let me know that we had been reported to be touching the cave formations, something that was strictly forbidden.  Either it was a case of mistaken identity, misinterpretation of actions, or maybe Dad had touched a stalagmite while I was taking pictures.  We got a polite warning to keep our hands to ourselves – no touching of rock is permitted in the cave.

Walnut Canyon Road descends down to the canyon floor, where we found evidence of recent flood activity. We could see debris left by water, but the arroyo was dry. The main entrance road to Carlsbad Canyon NP is on top of the hill in the background.

The Park Service has done a fantastic job with the lighting in the cave.  Lights are indirect and use a variety of bulbs.  Each type of light has its own “color temperature” due to the materials that emit the light.  The Park Service has matched incandescent, fluorescent, and mercury vapor lights to the minerals in the cave to bring out the natural colors.  Though you can see various colors in the rocks, no colored lights were used.  The color temperature of the light source brings out the natural color within the rock.

Walnut Canyon Drive

We did not take any tours of the other rooms in the cave.  Dad was pretty tired after walking around the Big Room.  Instead, we took a driving tour of Walnut Canyon.  I was hoping to see some wildlife, but the sun was still high in the sky and the birds were under cover.

Barbary Sheep are native to North Africa. They have been introduced to the American Southwest as a game species.

While Blaze is an SUV, he does not have 4-wheel drive, and was a little worried about driving to the bottom of Walnut Canyon.  Blaze handled the descent with aplomb, but while we were stopped on a slope scanning the brush for birds, Blaze’s low fuel warning light came on.  No problem, this is probably due to all the fuel flowing to the forward part of the fuel tank, away from the sensor.  Except that once level again, the fuel gauge continued to show “empty” and the low fuel warning stayed on.

What happened?  Did a fuel line break during the descent to the bottom of Walnut Canyon?  Were we to be stranded off the main road where help would not be passing by?  An external reconnaissance found no evidence of a fuel leak, so we carried on.  Eventually, after 20-30 minutes, the fuel gauge returned to a normal reading and the fuel light went off.

Barbary sheep are normally difficult to see, but this herd was grazing on the slope next to the road and seemed in no hurry to leave.

Coming up out of Walnut Canyon, we took the main entrance road back to the exit from Carlsbad Canyon NP.  On the mountain slope next to the road we saw a herd of Barbary Sheep contentedly grazing.  I quickly stopped and snapped some photos, afraid they would leave at any moment.  The Barbary Sheep paid no attention to us, so I grabbed Ricky’s other lens, a Sakar 80-250 zoom, installed it onto Penny, and got some good close shots.

Roadside Markers and Signs

I like to learn about the history of the countryside I travel through.  Roadside markers are a good way to do this.  Here’s a selection of the markers found near Hobbs, NM on this road trip adventure.

We stayed two nights in a hotel in Carlsbad, NM. The faint odor of hydrocarbons permeated the air, due to the large number of oil and gas well in the area.

There is not much in Hobbs except for large numbers of shops catering to all the services needed on the oil fields. But with a sign like this you won't miss the town.

Hobbs is a hub for the oil and gas industry in southern New Mexico.

The section of US 180 passing through Hobbs is dedicated to Kenneth Towle, a NM highway commissioner hailing from Hobbs.

On the way from Hobbs to Carlsbad, we were treated to one of the most spectacular sunsets ever.

While traveling through Texas, we stopped at signs commemorating events in the Texas War of Independence and the days of the railroad barons.

36 of Dawson's company were killed by artillery during the Battle of Salado Creek, in which 210 Texans repelled an invasion by 1600 Mexican troops on September 17, 1842.

300,000 acres were awarded to the wrong railroad company in 1873. It took 17 years for the error to be resolved, and caused much distress to the people who had bought land from the railroad that did not legally own the land.

Researching Watermarks

I’m looking for some software to put a watermark on the photos I publish in the blog.

Impression for iPhoto

The first watermarking software I looked at was Impression.  The attraction is that this is a plugin for iPhoto.  I assumed that this meant it would seamlessly integrate into my work flow.  Here are my impressions of Impression after using the evaluation version.

  • Impression is easy to install.  I downloaded the disk image, unzipped it, clicked on the install package, and that was it.  I did not like that there was no Readme or other instructions on the install disk.  I usually like to know what goes where before installing.  However, no harm done.  The web site provides installation and uninstall instructions.
  • Impression can use an image in PNG or PSD format, or a text file in RTF format for the watermark.  I used TextEdit to create a copyright notice in RTF format.  Interestingly, once I told Impression where to find the file, changes to the watermark file showed up automatically.  There was no need to do any setup to incorporate a changed watermark file.
  • Impression works in the file export window.  This window gains an Impression tab from which you can select the watermark file, manipulate it in various ways (rotation, margin, transparency, location, scale) (it remembers your selections from session to session), and save the watermarked photo.
  • The save button copies the original image to another one containing the watermark, then imports the watermarked image into iPhoto.  You end up with two images, one with a watermark and the other without.  My test image was a JPG sized at 3.9 MB.  The watermarked image was a JPG sized at 9.8 MB.  That is over twice the size, just for adding a watermark.  The watermarked image is saved to the original file name with “-WM” appended.  For example, IMGP0021.jpg becomes IMGP0021-WM.jpg.
  • Impression does not retain all the meta data from the original photo.  Using the Info window of iPhoto 11, I noticed that the following data is missing or changed.
    • Title was deleted.  It defaulted to the file name.
    • Description was deleted.
    • Location (GPS) was deleted.
    • Camera lens information was deleted.
    • Faces were deleted.
    • Keywords were deleted.
  • Deletion of meta data is pretty much a show stopper for me.  Impression does not seem to fit my work flow at this time.
    • I just want to export photos with a watermark.  Other than the addition of a watermark, the exported photos should be the same as the original in iPhoto.
    • I don’t see the need to store watermarked photos in iPhoto.  Yes, I could delete after exporting, but that is an extra step.
    • Actually, three extra steps …
      • Watermark photos with Impression
      • Export watermarked photos to files
      • Delete watermarked photos from iPhoto
    • When exporting, I use the photo title as the exported file name.  This is much more meaningful in my blog and other programs like EveryTrail than the file name assigned by the camera.  I don’t have to title the photos if the file name is the title.
    • Some web sites I use, such as EveryTrail, locate photos using the GPS location tags.  I don’t use Picasa but I understand it also locates photos based on GPS tags.  I want photos that are watermarked and geolocated, and Impression does not support that.
  • I think what would work for me is a checkbox on the export window that selects watermark or no watermark.  A button next to it would provide access to the watermark setup.
  • Impression retails for $14.90.

iWatermark

The second software I tested was iWatermark.  iWatermark is a stand-alone program, as opposed to a plug-in.  It does have some integration with iPhoto, in that you can select an iPhoto album as the input.  Here are my impressions of iWatermark after using the evaluation version.

  • iWatermark is easy to install.  It comes on a disk image (.dmg) file with the application, a Readme, and instructions for purchasing.  Actually, there are no installation instructions in the Readme; I just dragged the application to my Applications folder and double clicked it to open.
  • iWatermark can process files in PICT, BMP, TIFF, PNG, JPEG, and GIF formats.  It can open even more formats by using Quicktime, according to the documentation.  I tested the JPEG capability because that fits my workflow, and tried DNG format because I was investigating RAW formats at the time.  iWatermark did not process an image in DNG format, though it did not produce an error and did produce an output file that was blank except for the watermark itself.
  • iWatermark includes a watermark editor.  Text is entered directly in the editor, and images can be imported.  The included Help did not list the types of files that could be used for watermarks.  I scanned a folder containing different types of files; .jpg, .gif, and .png files were available, while other types that were clearly not images, such as .pdf and .html were grayed out.
  • iWatermark claims to maintain meta data, and this appears to be the case.  I exported images from iPhoto to JPG format files.  I batch processed the files through iWatermark, creating thumbnails in the process.  Meta Data was preserved in the watermarked files as follows:
    • General, Exif, GPS, and TIFF groups were unchanged.
    • JFIF group added the Progressive tag.
    • IPTC group added the Copyright Notice tag.
    • Meta data was not preserved in the thumbnail images.
  • iWatermark provides the capability to insert IPTC meta data.  I told it to insert the Copyright Notice tag.  It did so without destroying existing IPTC tags.
  • Side observation: iPhoto evidently does not preserve IPTC meta data upon importing images.  I imported images that contained the City, Country, and Province/State tags in the IPTC group.  Exported images contained only Caption/Description and Title tags, to which iWatermark added Copyright Notice.
  • iWatermark can create dynamic watermarks based on meta data, and also create IPTC tags based on meta data.  I did not test this capability.
  • iWatermark retails for $18.00. $20.00 (price increased between when I did the review and when I bought it.)

DropWaterMark

The third software I tested was DropWaterMark.  DropWaterMark is a stand-alone program, as opposed to a plug-in.  It does not have any integration with iPhoto.  Here are my impressions of iWatermark after using the evaluation version.

  • DropWaterMark is easy to install.  On the install disk image drag the DropWaterMark folder to the Applications folder.  First time opening the application presents a configuration screen.  There is a ReadMe, but I did not need to refer to it.  I only opened the ReadMe when I wanted to delete the developer’s logo from the watermark.  However, that cannot be done in the evaluation version.
  • DropWaterMark outputs files only in JPG format.  It will accept files in other formats, but does not list them.  I tried a DNG file but it was not accepted.
  • DropWaterMark allows for two lines of text and an image as watermarks.  Each can be independently positioned, so you could have a watermark in three places, such as a line of text in two corners and an image in the center.
  • Text watermarks are created in DropWaterMark.  Image watermark is imported and then edited within the application.
  • Meta data is preserved as follows:
    • General, JFIF, TIFF groups are unchanged.
    • Exif group added the Color Space tag with value Uncalibrated.  I’m not sure where the value for this tag comes from.
    • GPS group added the GPS Version tag.  Value is set to 2.2.  I found this interesting as there did not seem to any way DropWaterMark could have gotten the value for this tag.  It seems to have been made up.
    • IPTC group added the Keywords tag with no values.  I could find no way to specify keywords to be added.  Also, no way to specify IPTC tags to be added.
  • No capability to create dynamic watermarks or IPTC tags based on meta data.
  • DropWaterMark can change nonvisual data such as creation date, modification date, and file comment.  It can do this as part of watermarking the image, or separately without changing the image.
  • I tried dropping a file on the application icon.  This opened the app and loaded the image, but there were manual steps involved in completing the watermark process.  I was hoping drag-and-drop would work completely automatically.
  • DropWaterMark retails for $16.50.

ImageWell

Finally I tested ImageWell.  ImageWell is more than just watermarking software.  It also has the capability to edit photos, including a simple method of annotation.  This immediately got my attention as my current method of annotating images takes a lot of steps.  Here are my impressions of ImageWell using the evaluation version.

  • ImageWell is easy to install.  Just drag the app to the Applications folder.
  • Running ImageWell is easy as well.  A little window sits on the desktop to which you drag images.  It took me a few minutes to get used to the interface, but after that everything worked intuitively.
  • Surprisingly, ImageWell accepted an image in .DNG format.  This is an archival file format for RAW images.  Output is only in .JPG, .TIFF, or .PNG.
  • I tried a few simple annotations, arrow and text box.  It was easy and worked as expected.
  • The watermark text had to be retyped every time I worked on a new image.  I’m sure there is a way to make it stick, and ImageWell advertises a batch mode, but I did not test that feature.
  • I was getting ready to really like this product, when I looked at the meta data in the output images.  Meta Data is not preserved.  Bummer!
    • In the General group, the Orientation, Pixel Width, and Profile Name tags were deleted.
    • In the Exif group, all tags except Pixel X Dimension and Pixel Y Dimension were deleted.
    • The GPS, IPTC, and TIFF groups were deleted entirely.
    • The JFIF group had some interesting changes.
      • Density Unit changed from 1 to 0.
      • X Density and Y Density changed from 72 to 1.
  • I like the user interface and annotation capabilities of ImageWell, and the user interface is pretty good.  However, not preserving the meta data is a showstopper for me.  I at least need to have position (GPS) information preserved.
  • ImageWell retails for $19.95.

Geotagging iPhone Photos – Metadata Tags

On April 18 I went on a hiking and geocaching day trip.  I used my iPhone to take pictures.  I expected the photos to be tagged with the location they were taken, using the GPS built into the iPhone, and that I would be able to import these geotagged photos into the Garmin BaseCamp application.  Eventually the photos would be linked to maps on this blog, though I haven’t figured out how to do that yet.  This post is about what I discovered about geotagging photos taken by the iPhone; there will be another post about the day trip.

I have a knack for making things much harder than they ought to be.  Uploading pictures to iPhoto was easy, and I spent some time cropping and editing them.  Then I uploaded the day’s tracks from the Garmin GPS 76C receiver to BaseCamp and spent some time joining and splitting tracks into the segments I wanted.  This also was straightforward.  Now it was time to import the pictures.  I exported the photos from iPhoto and imported them into BaseCamp.  BaseCamp did not recognize the photos as being geotagged!

Geotag Detective Story

One reason I write these posts is that I find technical instructions often assume a level of knowledge on the part of the reader that is not there.  Often it is the very most basic information that is missing.  I found that to be the case when researching the relationship between photos geotagged by iPhone and the inability of BaseCamp to recognize those geotags.

The first thing I did was to go back to iPhoto to try to find the location data for the photos.  Of course I was unable to find it.  Turns out I’m using iPhoto ’08 and iPhoto ’09 is the first version to recognize location tags.  iPhoto ’09 is only available as part of iLife ’09 suite.  I don’t use the other parts of iLife enough to warrant purchasing the whole suite just to upgrade iPhoto.  (I understand that Picasa understands photo geotags, but all my pictures are in iPhoto and I’m not ready to change just yet.)

BaseCamp has the ability to geotag digital photos by comparing the time tag of the photo to a track file.  This actually works pretty well.  I used this capability to geotag the iPhone photos by comparing with the tracks from the GPS 76C.  Once BaseCamp had geotagged the picture files, it was able to import them. However, I was not satisfied — the iPhone is supposed to geotag the pictures it takes and I wanted to know why it apparently was not doing so.

A Google search turned up very little about geotagging on the iPhone.  All you have to do is turn on Location Services and all photos will automatically be geotagged.  I had Location Services turned on, but apparently no geotags.

During my hike, I had regularly turned off the iPhone display when not taking pictures.  Maybe the iPhone did not have time to lock onto the GPS satellites before I took a picture, so it did not geotag the photos because it did not know where it was?  (There was no cell service, so GPS was the only way to get a location.)  To test this I brought up the Map app and almost immediately got the little blue pulsing pin showing my location, showing that Location Services knew the location of the iPhone.  (I was actually quite impressed that my actual location showed up.  This was indoors and the GPS signals would have had to come in through the windows.  When Location Services has to use non-GPS data, like cell tower triangulation, it puts my location about 5 miles away.)  I snapped a picture of my desk, uploaded to iPhoto, exported to a file, imported to BaseCamp.  It was not recognized as a geotagged photo.

Some more googling turned up that perhaps exporting the JPG from iPhoto does not include the location data, especially since my version of iPhoto does not know about locations.  Dragging the photo from the library to the hard drive is supposed to solve that.  Nope.  Did not work.

More googling.  People are very sure that the iPhone does indeed geotag photos, but various desktop applications don’t recognize the tags.  Some people email their photos directly from the iPhone to Flickr.  So I emailed my photo to myself, saved it to a file, and imported into BaseCamp, thus skipping iPhoto and any problems it might have altogether.  Still no success; BaseCamp does not recognize that this is a geotagged photo.  The problem could be with BaseCamp (though it imports other geotagged photos properly) or with the iPhone (though no one has reported this problem online).  I don’t have a second application that recognizes geotags with which to do a comparison.  (Actually, Preview displays geotags, but I did not realize it at the time.)

More googling, this time concentrating on BaseCamp rather than iPhone.  Finally I hit pay dirt with this forum post:

The key information that is missing from your photo is the GPSVersionID. BaseCamp looks for the GPSVersionID to see if a geotag is present, and in your photo it doesn’t find it so it doesn’t look any further.

This same forum thread made a passing reference to ExifTool, so I looked it up.  ExifTool is one of those wonderful open source tools authors make available to everyone at no charge.  Here’s the description from the tool’s home page.

ExifTool is a platform-independent Perl library plus a command-line application for reading, writing and editing meta information in a wide variety of files. ExifTool supports many different metadata formats including EXIF, GPS, IPTC, XMP, JFIF, GeoTIFF, ICC Profile, Photoshop IRB, FlashPix, AFCP and ID3, as well as the maker notes of many digital cameras by Canon, Casio, FujiFilm, HP, JVC/Victor, Kodak, Leaf, Minolta/Konica-Minolta, Nikon, Olympus/Epson, Panasonic/Leica, Pentax/Asahi, Ricoh, Samsung, Sanyo, Sigma/Foveon and Sony.

Downloading and installing ExifTool was a snap.  It has a command-line interface, but I have a passing familiarity with Unix so using Terminal didn’t faze me.  Looking at my test photo that I emailed directly from the iPhone I see that it is indeed geotagged, and that it is missing the GPSVersionID tag.

GPS Latitude Ref                : North
GPS Longitude Ref               : West
GPS Altitude Ref                : Above Sea Level
GPS Time Stamp                  : 20:54:55.64
GPS Dilution Of Precision       : 5
GPS Altitude                    : 1490 m Above Sea Level
GPS Latitude                    : 35 deg 14' 37.20" N
GPS Longitude                   : 106 deg 37' 54.60" W
GPS Position                    : 35 deg 14' 37.20" N, 106 deg 37' 54.60" W

Next step was to see whether BaseCamp would recognize the geotags in the photo if I added the GPSVersionID tag.  The GPSVersionID tag must be in a specific format — I got a hint in this forum post.  I was able to use ExifTool to add the GPSVersionID tag to a geotagged photo.  BaseCamp then recognized the geotags and imported the photo at a specific location.  YAY!!  My inner geek is pleased!

While writing this post, I reviewed the research and found hints that Preview recognizes location data.  Sure enough, you can Show Inspector from the Tools menu to pop up a small More Info window that shows metadata about the photo.  There’s a tab that shows GPS metadata.  When looking at the photo to which I had added the GPSVersionID tag, the GPS Version was shown.  Otherwise GPS Version did not appear.  This is a nicer way of checking the metadata tags than ExifTool, as you can see the photo and metadata at the same time, plus it uses a GUI for navigation.  But you can’t modify the file like you can with ExifTool.

Summary – What I Learned About Geotags

Metadata

  • Metadata refers to information about an object, such as a JPG image, as opposed to the object itself.  The object might be an image of a flower.  Metadata could include the size of the image, the f-stop of the camera taking the picture, and the location where the picture was taken.
  • Embedding metadata in a JPG file is evidently quite complex.  See this post by Phil Harvey to get an appreciation of the complexity.
  • Metadata is identified by tag names.  There are thousands of tag names.
  • Location metadata is identified by tag names that start with GPS.  The GPSVersionID tag is one of these.
  • The GPSVersionID tag has the format n.n.n.n, for example, 2.2.0.0.  However, BaseCamp writes the tag as .. and this seems to work.

iPhone 3G

  • The camera built in to the iPhone 3G with OS 3.0 does geotag photos, but does not include the GPSVersionID tag, which is needed by some applications like Garmin BaseCamp.
  • Geotagging is enabled by turning on Location Services under Settings/General.  That’s it — no dialogs, no warnings, not even a status indicator in the Camera app to tell you that photos are being geotagged.

iPhoto ’08

  • iPhoto ’08 does not know about geotags.  iPhoto ’09 is the first version to recognize location data.
  • iPhoto ’08 exports metadata, including geotags, with photos, even though it does not recognize the geotags.

Preview 5.0

Inspector Window from Preview

Preview showing GPS metadata

  • Preview displays some metadata in the Inspector window.  Bring up the Inspector window from Tools/Show Inspector.
  • Available categories of metadata are
    • General – information about the image, such as size in pixels and color profile.
    • Exif – information about the camera and and settings when taking the photo, such as fNumber and exposure mode.
    • GPS – location data about the image, such as latitude, longitude, altitude.
    • TIFF – information related to TIFF image format, such as orientation and resolution.
  • Preview will show the GPSVersionID tag if it exists.

Garmin BaseCamp 3.0.1.0

  • BaseCamp will import geotagged photos and locate them on its map.
  • BaseCamp looks for the GPSVersionID tag to determine whether the photo is geotagged.  If it does not find the GPSVersionID tag, it stops looking, even if the location tags are embedded.  This means BaseCamp does not recognize photos from the iPhone as being geotagged because of the missing GPSVersionID tag.
  • BaseCamp can geotag photos by comparing the photo timestamp with a GPS track log.  The photo is located at the location in the track log that has a timestamp nearest to the timestamp of the photo.

ExifTool 8.18

  • ExifTool is a free tool that reads and writes metadata in a variety of file formats.  It is available for Mac OS X, Windows, and Unix systems.  ExifTool is written in Perl.
  • On the Mac, ExifTool uses a command-line interface from within Terminal.  There is no GUI.  The tool’s home page states there is a GUI for Windows.
  • I found ExifTool to be easy to install and to use.  ExifTool displayed all the metadata contained within the JPG image files I was working with.
  • It was easy to add the missing GPSVersionID tag.  ExifTool caught my attempts to write the tag in an invalid format.  It automatically creates a backup copy of the file being modified to allow recovery if a mistake is made.
  • ExifTool can do a lot of  stuff with metadata that I haven’t tried.  Not only can it geotag photos from a track log, it can also create a track log from geotagged photos!  How cool is that?