MapSnap GPS, a great "why didn't I think of that" WP app

I've never owned a cellphone and I was looking through the store for stuff that I might find useful if I actually DID own a WP8 device. Along with MIDI controllers and virtual instruments, outdoor navigation apps would be quite useful for me.
I found this app while looking at GPS and geocaching apps. It's such a great concept because sometimes the paper charts are better than anything you can find online and I'm rarely looking for street maps anyway.

It's called MapSnap GPS for Windows Phone 7 by Simon McKenzie

Nice!

Wow, that's actually a really useful idea.

There should really be a standard way to provide phones with a custom map with GPS references (and if applicable, path information for directions). That way places like theme parks, camp sites or nature reserves could just point you to a download link for a custom, detailed map with information that you wouldn't find on a regular map and which your phone will be able to use instantly.

The picture taking thing is a brilliant idea to use existing maps, and really great if there's no connectivity, but for places that do have a working connection, providing e.g. a hiking trail map that's pre-digitized and pre-calibrated for GPS use would be a really great service to provide at the visitor centre of a national park.

But to be able to do that, there should be a widely accepted format to provide such maps in. Otherwise, it's too difficult.

There's an opportunity for this guy here too, if he could provide a way for people to share pre-calibrated maps. You need a GPS-enabled map of Disney World? Sure, you could go there, photograph a sign, and calibrate it. Or you could just download one that someone already made. It could of course tell you what maps there are for nearby places if you do have connectivity in the actual place.

MapSnap was the first App I bought!  I've only used it once so far though (don't get a chance to go out walking often). I found the initial calibration a little tricky (you have to physically be at a identifiable spot on the map and then repeat for another identifiable spot).  I fluffed the first calibration so it was about 100 yards out, but we recalibrated and it was fine.

It's useful for the collection of old walking books we have.

I did make a start on a walkers app that used GPX files (with proprietary extensions) to allow you to record and share walks with notes and photos along the trail. Perhaps I'll finally finish it for WP8.

Herbie 

The biggest problem I can see with this app is that sometimes the maps you find on "you are here" signs are just artists renditions of the area and aren't exactly accurate but it would be pretty easy to see when that's the case.
I suppose you could also use images from screenshots taken from Bing/Google but I don't know if it lets you import images from anywhere.

Two days ago I walked 11KM through the woods trying to find a giant boulder I spotted on satellite maps and this app would have been very useful in conjunction with a top down satellite image of the area from Google Maps because I don't know if there was reliable cell service out there but GPS is usually reliable as long is you're not under large trees.

I used MapSnap last year at Busch Gardens Williamsburg. It works. Did have some issues of it showing me in the bushes but other than that it was great. And that was pre mango.

29 minutes ago, Ion Todirel wrote

@Sven Groot:QR codes for the data and some sort of calibration points on the picture? that would be kind of cool

Cool concept, but it requires that the maps be drawn to scale, which isn't always the case.

that's really cool.

17 seconds ago, Ion Todirel wrote

@cbae:does it? I thought the point of the two calibration points is to calibrate the scale

The entire map still needs to be drawn to the same scale, though. And that's often not the case with tourist signs, which are more of a schematic drawing than an actual map.

What if you allowed for multiple calibration points and then, behind the scenes, applied typical image distorting algorithms to make it fit? There has to be a better use for those than just playing around with making funny faces, right? Couple it with some image analysis to try and determine "paths" that a user followed as they walked about and you could be well on the way to something seriously awesome.

Obviously for entirely stylised maps (Like the London Tube) it'd be useless, but even though tourist sign maps aren't always to-scale, they probably mostly accurate orientation-wise.

Lolz good catch, it won't work for Disneyland for sure. But trail map should be quite accurate, so, I think it is good enough.

Like I said before. The maps that are just stylized artists renditions are pretty easy to spot and they really aren't terribly useful in this case.

I can also see using this app with photos of topo maps that might be more detailed than what you can find online.

The current version of MapSnap GPS allows up to 3 calibration points, which covers rotation, scaling and skew, which is enough to take care of nearly all camera-related distortion (lens distortion notwithstanding), but the idea of contextual calibration from track logs, as suggested by @AndyC, is probably going to involve too much processing (and battery life). It's definitely something I've considered at times (I'm the author), but I tend to feel that with single-task apps like this one, it's worth adhering to the KISS principle!

Of more concern is the idea that every once in a while, an algorithm like that is definitely going to get it wrong. Since this is a navigation app, I'd be very concerned about people getting lost due to an over-clever algorithm...

@SimonMcKenzie:There's a show on Channel 9 called Hot Apps. Laura doesn't seem to have made any new episodes lately but your app would definitely be worthy of the show.

Thanks @dentaku,

I've sent a message to Laura, so maybe it'll get into an upcoming episode. Fingers crossed!