Exploring EXIF

I&#x27;m the author of the osxphotos[0] tool mentioned in the article. For photos in an Apple Photos library, osxphotos gives you access to a rich set of metadata beyond what&#x27;s in the actual EXIF&#x2F;IPTC&#x2F;XMP of the image. Apple performs object classification and other AI techniques on your images but generally doesn&#x27;t expose this to the user. For example, photos are categorized as to object in them (dog, cat, breed of dog, etc.), rich reverse geolocation info (neighborhood, landmarks, etc.) and an interesting set of scores such as &quot;overall aesthetic&quot;, &quot;pleasant camera tilt&quot;, &quot;harmonious colors&quot;, etc. These can be queried using osxphotos, either from the command line, or in your own python code. (Ref API docs[1])<p>For example, to find your &quot;best&quot; photos based on overall aesthetic score and add them to the album &quot;Best Photos&quot; you could run:<p>osxphotos query --query-eval &quot;photo.score.overall &gt; 0.8&quot; --add-to-album &quot;Best Photos&quot;<p>To find good photos with trees in them you could try something like:<p>osxphotos query --query-eval &quot;photo.score.overall &gt; 0.5&quot; --label Tree --add-to-album &quot;Good Tree Photos&quot;<p>There&#x27;s quite a bit of other interesting data in Photos that you can explore with osxphotos. Run `osxphotos inspect` and it will show you all the metadata for whichever photo is currently selected in the Photos app.<p>[0] <a href="https:&#x2F;&#x2F;github.com&#x2F;RhetTbull&#x2F;osxphotos">https:&#x2F;&#x2F;github.com&#x2F;RhetTbull&#x2F;osxphotos</a> [1] <a href="https:&#x2F;&#x2F;rhettbull.github.io&#x2F;osxphotos&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;rhettbull.github.io&#x2F;osxphotos&#x2F;</a>

&gt; the EXIF data marker (FFE1)<p>This isn&#x27;t quite right. That&#x27;s a JPEG application specific marker (APP1). It indicates that some additional data is embedded in the JPEG file at that point which should be interpreted in an application specific manner (e.g. skipped if the program doesn&#x27;t know how to handle it). That could be Exif tags but could also be other things (like XMP). An APP1 segment can be distinguished as Exif data based on the presence of the &quot;Exif&quot; string immediately after the segment size. (The tags themselves are stored in essentially a TIFF file embedded after the Exif identifier, if you&#x27;re curious.)

FYI if you didn’t already know: pdf files also have EXIF data. I just learned that recently.

Be careful about posting your phone camera images publicly if you’re protective of your privacy. Some social media trim location and other sensitive EXIF tags, but it’s best to not trust them.

I wonder how the GPS coords is actually encoded in the EXIF data, because I have a hard time believing they&#x27;re actually encoding it with as many significant digits as displayed by the website.<p>For the example they give, I&#x27;m counting 14 significant digits for GPSLatitude, and 16 for GPSLongitude, which is way more specific than a grain of sand, ref <a href="https:&#x2F;&#x2F;xkcd.com&#x2F;2170&#x2F;" rel="nofollow noreferrer">https:&#x2F;&#x2F;xkcd.com&#x2F;2170&#x2F;</a><p>I suppose it&#x27;s floating point, and of course that brings its own &quot;fun&quot; in displaying in decimal.<p>At least it also includes GPSPositioningError!

That is way more information in a single photo than I ever would have guessed.

Interesting post.<p>From the metadata of a person&#x27;s photos, you can extract, inter alia:<p>...whether they took some photos from a plane or helicopter (viewshed, angle and altitude are preserved);<p>...how conscientious someone is (by looking at their iPhone&#x27;s uptime, perhaps the over-conscientious person with an extreme uptime is borderline OCD?).

somewhat related, i used a tool to extract embedded jpeg preview images from raw images. much faster than actually using software to process the raw files if you just need to quickly share, your camera already &quot;developed&quot; them :)<p><a href="http:&#x2F;&#x2F;www.fsoft.it&#x2F;ERawP&#x2F;" rel="nofollow noreferrer">http:&#x2F;&#x2F;www.fsoft.it&#x2F;ERawP&#x2F;</a><p>exiftool apparently can extract these also:<p>exiftool -a -b -W %d%f_%t%-c.%s -preview:all dir<p>Extract all types of preview images (ThumbnailImage, PreviewImage, JpgFromRaw, etc.) from files in directory &quot;dir&quot;, adding the tag name to the output preview image file names.<p><a href="https:&#x2F;&#x2F;exiftool.org&#x2F;exiftool_pod.html" rel="nofollow noreferrer">https:&#x2F;&#x2F;exiftool.org&#x2F;exiftool_pod.html</a>

&gt; We have great tools for searching a single one of these dimensions, but we‘re severely lacking in combining all of them into an exploratory interface<p>I would recommend you to try an open-source semantic photo search app I&#x27;ve made, it&#x27;s called Queryable. See: <a href="https:&#x2F;&#x2F;github.com&#x2F;mazzzystar&#x2F;Queryable">https:&#x2F;&#x2F;github.com&#x2F;mazzzystar&#x2F;Queryable</a>

Doesn’t this information get stripped from photos, at least on iOS when you share them. Seems to be what I recall experiencing.

&gt; In fact, when you give an iOS app full access to your photo library, you&#x27;re giving all of this information [including GPS data] away too.<p>Scary.

Someone tell me does any library exists that handles exif, xmp, iptc and has machine output (json)?