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Show HN: Compass that points you to a photo's EXIF location

getphotofind.com

120 pointsgohnjanotis47 comments

I've been hiking and foraging for mushrooms and wild foods, so I made this simple utility app for iOS.

It lets you pick a photo you took (or that someone sent you) and then points you in the direction the photo was taken, kind of like a compass, based on the coordinates stored in the photo's EXIF data. It's basically a fast and easy way to mark locations and get back to them.

Originally I tried it in JavaScript, but iOS strips lat and lon info from photos when they're picked with a file input field. You can still find the beginnings of my hacked together JS version here: http://foodsfofree.herokuapp.com/

This is just a side project I built for fun since I hadn't built an iOS app before, so I'm not trying to turn it into a business or something, just wanted to share it!

You can also read more about it here on my blog: http://gohnjanotis.com/photo-find-v1-1-released/

Very neat idea, reminds me of the Gatherer add-on from WoW (http://www.curse.com/addons/wow/gatherer).

HA! That's amazing.

Ugh, flashbacks to hundreds of hours gathering herbs and ores with that add-on during my WoW addiction.

Great little app. I would go a little further -- let the app also take pics (with the GPS on), or simply remember places with tags on the spot. e.g. tag and say "parked car".

I sometimes do not leave the location on, however, I would still like the functionality of the app.

Great job!

Cool! A few years ago I was couch surfing at a stranger's house on the opposite side of the U.S. and found myself unable to find the house again after a late night at the bar. Didn't have the address because we had met on a bike trail and followed him home earlier. Eventually I remembered I had taken a picture of his cat, and sure enough it was geotagged directly on his living room!

Great idea ! Has been on my list for a while as well ;-)

> Originally I tried it in JavaScript, but iOS strips lat and lon info from photos when they're picked with a file input field.

Yes, that is how far I got. Good you went a step further.

I think there are options for expanding: because a photo is easier to share then a location plus it tells a lot about the location itself. Better then some numbers of shortened url.

Combined with compass navigation the user does not need internet (Apple, Google maps) to still be able to navigate to a location.

And why share just one photo ? Share a collection: interesting buildings in a city, or the best places with cakes (based on just the pictures of those cakes :-).

I still think a concept to think about more. Please continue.

Thanks! That's cool you tried the same thing!

Cool idea about the collections.

Another extension of it I also thought about is a version with some kind of node.js backend that's a little bit like Yo except whenever you and a friend have it open it points you at each other so you can find each other on foot as long as you have a decent internet connection and good GPS accuracy.

why don't they need Internet?

As long as you already have the app and photo on your phone it just uses the compass and GPS, which are both sensors built in to the iPhone and don't require internet.

sorry. I'm an idiot and didn't think about gps seperately from internet

It's a pretty good point actually! Because Airplane Mode disables GPS on the iPhone.

That's a little odd. Isn't GPS generally completely passive? That is, it should not be possible to cause any sort of interference.

I thought it was passive, too. I've googled a little in the past and some people say it's in the same chip as the cellular radios (and the whole chip gets knocked out in Airplane Mode). Others say the amplification of signals necessary could cause interference.

A radio receiver often uses a signal of an intermediate frequency: http://en.wikipedia.org/wiki/Intermediate_frequency

So a receiver that would appear functionally to be passive could still conceivably cause interference.

Cool. Was not aware of the usage of intermediate frequencies in radio receivers. Thanks for the knowledge :)

Phones often use A-GPS, which includes an active component: http://en.m.wikipedia.org/wiki/Assisted_GPS

This is true, but it seems like it should not be hard to disable AGPS in airplane mode.

This is a cool idea. I see it as a great utility for taking newer versions of photos years later or even just remembering where you parked.

Curious though when I installed it I only see kilometers but the screenshot on the website shows imperial units and I don't see any way to change it. Is there a way?

Edit: yeah just found the swipe to change units. I'm all for supporting apps and developers but $2 just to switch units? No thanks. Uninstalled. That's insane.

Edit 2: the biggest issue about the price is perceived value. Making this app cost $.99 or $1.99 itself? Not bad in my opinion. Development isn't free and I probably would have paid that. But when you move to an in-app purchasing model now the perceived value is a free app that is gouging you $2 just to switch from metric to imperial. Maybe the intent was to have as many people try it as possible and to hopefully make a little money from it but the way the in-app purchasing is structured it makes me feel like I'm being taken advantage of.

There's actually a screen you can swipe to to the left of the main screen where you can change the units, but I wanted to make an economic incentive for people to try SI so it'll cost ya! ;-)

Also, I apologize for the buggyness with that swiping... I should have used a UIPageViewController and will probably go fix it at some point.

You can read more about all this in my blog post, including the decision about distance units.

Neat! An "open in maps" option would be nice to get directions.

Yeah! Awesome to hear! I was already thinking about adding that because sometimes some driving or public transit is needed to get within walking range haha

Awesome idea, very creative. I'd love to see you keep working on this.

Android version when? ;)

Haha I know, I know... you're not the first to ask about Android!

The reason I tried JavaScript first was to start off cross-platform, but when that failed I developed for the hardware I use.

However, I've been meaning to try out some Android development, so maybe at some point...

If you need help with an Android port, I'd be glad to pitch in.

If you are searching for this in the app store, try searching for "Photo Find Ganotis". When I searched for "Photo Find" it matched like 1,500 apps, and gave up looking in those results.

Oh yeah! That part sucks. I should have done more name research first. I always tell people to search "photo find hiking" (quotes not necessary) because that's easier to spell than my last name and it's the only app that comes up.

Great idea. I always take a photo when parking at the airport, but recently learned this isn't much help in iOS when Lots D, E, F are adjacent but Lot C is half a mile away in a random direction.

Not to mention the poor reception you get using GPS in a parking garage!

I remember kinda similar concept implemented years ago for Openmoko and Maemo, but for geocaching - the app showed you just the arrow and the rest was up to you :)

I'm assuming this works with GPS data.

So this would not work with photos taken with a DSLR without a GPS module/attachment.

Am I correct?

It uses the EXIF data, so it would use the location data in the EXIF.

> So this would not work with photos taken with a DSLR without a GPS module/attachment.

Depends. You can also retroactively edit the EXIF data to reflect a location. It should work on those kinds of pictures, even though the original camera didn't have a GPS.

Correct, I should've been been more clear in my post; I meant location data in EXIF data that has been recorded by the/a GPS module.

I think this is so. Reading the developer's post it seems he had the idea to use pictures taken with his iPhone, which would include GPS data in the EXIF.

I think this is a fantastic idea.

I don't have much experience with DSLRs and didn't even know there were GPS modules for them, but that makes sense and is awesome!

But yep it just pulls the lat and lon from the EXIF data, so it should work fine. The standard for EXIF is degrees, minutes, seconds and then a separate "Ref" value for N or S.

I have to do a little math on those values to turn everything into a decimal format, but based on this standard I would assume everything saving location in EXIF data would use this same format so it should all be compatible:

http://www.exiv2.org/Exif2-2.PDF (See page 53 of the PDF under the heading GPSLatitude)

If you test it, let me know!

I just might do that!

My initial thought was pulling some of my favorite shots from Flickr and using this to find the location of where the shot was taken. Great for finding those hidden photoshoot locations!

Unfortunately most DSLRs do not have the GPS built it. It's usually an add-on attachment.

Very simple, very cool. Nicely done!

Thanks! I really appreciate hearing that!

Very nice, downloaded :) It would be cool to have an extension right in the Photos app.

The compass isn't updating for me in iphone 6. Or is that one of the premium features?

Haha not a premium feature! Sometimes there are calibration issues. I meant to add some calibration checks and user feedback about needing to calibrate at some point.

Try rotating your phone around in a circle a bunch and then see if the compass starts moving and correcting itself.

Hi! Neat project, but hasn't iOS got a similar function built in already, where you can see all the pictures you took on a map?

Sure, but have you ever tried navigating to a photo that way?

The map doesn't show your location, and even if it did you would still need some kind of compass arrow, like the Google Maps app for iOS shows, to be able to navigate to it.

Also, this works by pasting a photo from the clipboard instead of just using photos in your library.

Great idea, but charging to show in feet? Ridiculous. Uninstalled.

OK, sorry you feel that way about SI!

I love the idea of charging to show in imperial units. That's some amazing pro-SI propaganda, we need more stuff like that :)

Thanks! It's about time.

This actually gave me an idea for a way to get people to pay for your app. Use metric in countries that use imperial units and vice versa. It would be an awful thing to do.

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