Re: [OSGeo-Discuss] Finding position based on horizon profile?
These all are pretty cool, but all seem to work based on knowing the current location, which is is the unknown in Michael's hypothetical problem. But that said some of the tech behind these tools might be useful in comparing photo to a potential reference image. This is a very interesting and intriguing problem. -Steve On 3/29/2011 10:28 AM, Mr. Puneet Kishor wrote: On Mar 29, 2011, at 9:23 AM, Ian Turton wrote: On 28 March 2011 16:48, Michael P. Gerlek wrote: Consider the following hypothetical problem: Assume we have a good elevation data set for a large region of the earth -- say, an entire mountain range. Now let's say we have a photograph taken from the ground, the horizon of which shows the profile of a couple of the mountains in that range. Can you tell me where the photograph was taken from? Any pointers to research in this area would be appreciated. I think that http://www.heywhatsthat.com/ does some of what you want. I'm on a very slow hotel internet connection so I can't actually get it to load just now. But my Delicious tags seem to indicate it's an answer. Yes, that is the one I have been thinking of since the start of this thread. Thanks Ian, for suggesting heywhatsthat.com. It was pointed out either on this list or on geowanking a long time ago, and I just couldn't remember it. It is pretty cool. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] Finding position based on horizon profile?
On Mar 29, 2011, at 9:23 AM, Ian Turton wrote: > On 28 March 2011 16:48, Michael P. Gerlek wrote: >> Consider the following hypothetical problem: >> >> Assume we have a good elevation data set for a large region of the earth -- >> say, an entire mountain range. Now let's say we have a photograph taken >> from the ground, the horizon of which shows the profile of a couple of the >> mountains in that range. Can you tell me where the photograph was taken >> from? >> >> Any pointers to research in this area would be appreciated. > > I think that http://www.heywhatsthat.com/ does some of what you want. > I'm on a very slow hotel internet connection so I can't actually get > it to load just now. But my Delicious tags seem to indicate it's an > answer. > Yes, that is the one I have been thinking of since the start of this thread. Thanks Ian, for suggesting heywhatsthat.com. It was pointed out either on this list or on geowanking a long time ago, and I just couldn't remember it. It is pretty cool. Puneet. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] Finding position based on horizon profile?
On 28 March 2011 16:48, Michael P. Gerlek wrote: > Consider the following hypothetical problem: > > Assume we have a good elevation data set for a large region of the earth -- > say, an entire mountain range. Now let's say we have a photograph taken > from the ground, the horizon of which shows the profile of a couple of the > mountains in that range. Can you tell me where the photograph was taken > from? > > Any pointers to research in this area would be appreciated. I think that http://www.heywhatsthat.com/ does some of what you want. I'm on a very slow hotel internet connection so I can't actually get it to load just now. But my Delicious tags seem to indicate it's an answer. Ian -- Ian Turton ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] Finding position based on horizon profile?
Dave, there's a (non open source) augmented reality application for the iPhone and Android that shows you what peaks you are looking at through your phone camera. http://peakar.salzburgresearch.at/ They say that all the data they use comes from OpenStreetMap (see the FAQ). Not sure if this is solely using the compass or whether it does image recognition also. On Mon, Mar 28, 2011 at 7:57 PM, Dave Patton wrote: > On 2011/03/28 1:48 PM, Michael P. Gerlek wrote: > >> Consider the following hypothetical problem: >> >> Assume we have a good elevation data set for a large region of the earth >> -- >> say, an entire mountain range. Now let's say we have a photograph taken >> from the ground, the horizon of which shows the profile of a couple of the >> mountains in that range. Can you tell me where the photograph was taken >> from? >> > > Something I've been interested in is sort of the > reverse problem - knowing where a photograph was > taken(e.g. you have a GPS waypoint), and maybe > even a bearing (e.g. from a compass), can you > tell me what mountains are in the photograph? > > Because of the potential viewscape, having good > elevation data for "an entire mountain range" > may not be sufficient. For example: > http://members.shaw.ca/davepatton/photos/boise2.jpg > That was taken On the Pinecone Lake Trail, near > Squamish, B.C., Canada. The view looks past Hopefull > Meadows over the Boise Valley, with Mount Baker > (Washington State, USA) in the distance. > > -- > Dave Patton > CIS Canadian Information Systems > Victoria, B.C. > > Degree Confluence Project: > Canadian Coordinator > Technical Coordinator > http://www.confluence.org/ > > Personal website: > Maps, GPS, etc. > http://members.shaw.ca/davepatton/ > > ___ > Discuss mailing list > Discuss@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/discuss > ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] Finding position based on horizon profile?
On 2011/03/28 1:48 PM, Michael P. Gerlek wrote: Consider the following hypothetical problem: Assume we have a good elevation data set for a large region of the earth -- say, an entire mountain range. Now let's say we have a photograph taken from the ground, the horizon of which shows the profile of a couple of the mountains in that range. Can you tell me where the photograph was taken from? Something I've been interested in is sort of the reverse problem - knowing where a photograph was taken(e.g. you have a GPS waypoint), and maybe even a bearing (e.g. from a compass), can you tell me what mountains are in the photograph? Because of the potential viewscape, having good elevation data for "an entire mountain range" may not be sufficient. For example: http://members.shaw.ca/davepatton/photos/boise2.jpg That was taken On the Pinecone Lake Trail, near Squamish, B.C., Canada. The view looks past Hopefull Meadows over the Boise Valley, with Mount Baker (Washington State, USA) in the distance. -- Dave Patton CIS Canadian Information Systems Victoria, B.C. Degree Confluence Project: Canadian Coordinator Technical Coordinator http://www.confluence.org/ Personal website: Maps, GPS, etc. http://members.shaw.ca/davepatton/ ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] Finding position based on horizon profile?
Ok, after thinking about this a little and doing some more googling about. It is hard to find the right terms for this question. Anyway this is one approach that I thought of. Given that you had a constrained area - what ever that might be. You might generate horizon profiles of the area based on prominent peaks or features, by viewing those areas from outside the area of interest. The goal being to generate wireframe profiles of the ridges and mountains in say N-degree steps about the prominent feature. These would all get stored for future reference. Now given a photograph, identify the horizon and any other significant terrain features as wire frames. Now try to match these against the sample references created above. This will need to be done very approximately like just matching peaks and allowing for horizontal spread based on point of view distance and relative height differences from the reference perspective and the camera perspective. The idea here is to narrow the field of possible perspective images from 1000's to 100's. This matching might be achieved by doing a linear regression that can only distort your image profiles by stretching/compressing the image horizontally and/or vertically and computing a least square fit against the reference. You would want to keep the images centers aligned right-left because you are trying to fine the reference image the best aligns with your image because this will give you the heading onto which you can then dos more detailed analysis. You can slide the images up-down relative to one another. Or try to analyze matching prominent features in the profile that match right-left from center. Then a detailed analysis of this smaller number of possible viewing angles and be analyzed. If you can uniquely identify 2-3 features, then it should be possible to analyze the distance between them and their relative heights and widths to compute heading, distance and azimuth of the camera that you could then try to place more accurately on your DEM. Anyway, having never done anything like this, this would be how I would approach it without additional research to direct me in another direction. -Steve On 3/28/2011 5:27 PM, Michael P. Gerlek wrote: Well, yes, I did do that first and have some angles on the more conventional aspects of this, e.g. missile guidance. Being new to this area, though, I thought I'd put out a query to see what else might turn up in the open source realm (pure R&D being one thing; hackable code is something quite different sometimes). [that said, sometimes it's hard to even frame the right questions when one is in a brand new area..] -mpg -Original Message- From: Stephen Woodbridge [mailto:wood...@swoodbridge.com] Sent: Monday, March 28, 2011 2:16 PM To: m...@flaxen.com; OSGeo Discussions Subject: Re: [OSGeo-Discuss] Finding position based on horizon profile? On 3/28/2011 4:48 PM, Michael P. Gerlek wrote: Consider the following hypothetical problem: Assume we have a good elevation data set for a large region of the earth -- say, an entire mountain range. Now let's say we have a photograph taken from the ground, the horizon of which shows the profile of a couple of the mountains in that range. Can you tell me where the photograph was taken from? Any pointers to research in this area would be appreciated. Micheal, Does this help? http://www.google.com/#q=matching++"terrain+profile"; -Steve ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] Finding position based on horizon profile?
It's definitely in the field of augmented reality research - I had been looking for the same answer a few years ago and was pointed to a (closed access) research paper - never did get beyond that restriction :/ I'm very interested in any results you get to. Tyler On 2011-03-28, at 1:48 PM, Michael P. Gerlek wrote: > Consider the following hypothetical problem: > > Assume we have a good elevation data set for a large region of the earth -- > say, an entire mountain range. Now let's say we have a photograph taken > from the ground, the horizon of which shows the profile of a couple of the > mountains in that range. Can you tell me where the photograph was taken > from? > > Any pointers to research in this area would be appreciated. > > -mpg > > > ___ > Discuss mailing list > Discuss@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] Finding position based on horizon profile?
Hi, I can't remember the project exactly, but I think I saw do something similar those guys here: http://tev.fbk.eu/marmota/ http://tev.fbk.eu/marmota/eagleeye/ They usually are keen to open source, but I am not sure if that is the case here. In case you would have to contact them. Andrea On Mon, Mar 28, 2011 at 10:48 PM, Michael P. Gerlek wrote: > Consider the following hypothetical problem: > > Assume we have a good elevation data set for a large region of the earth -- > say, an entire mountain range. Now let's say we have a photograph taken > from the ground, the horizon of which shows the profile of a couple of the > mountains in that range. Can you tell me where the photograph was taken > from? > > Any pointers to research in this area would be appreciated. > > -mpg > > > ___ > Discuss mailing list > Discuss@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/discuss > ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] Finding position based on horizon profile?
On 3/28/2011 4:48 PM, Michael P. Gerlek wrote: Consider the following hypothetical problem: Assume we have a good elevation data set for a large region of the earth -- say, an entire mountain range. Now let's say we have a photograph taken from the ground, the horizon of which shows the profile of a couple of the mountains in that range. Can you tell me where the photograph was taken from? Any pointers to research in this area would be appreciated. Micheal, Does this help? http://www.google.com/#q=matching++"terrain+profile"; -Steve ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
RE: [OSGeo-Discuss] Finding position based on horizon profile?
Well, yes, I did do that first and have some angles on the more conventional aspects of this, e.g. missile guidance. Being new to this area, though, I thought I'd put out a query to see what else might turn up in the open source realm (pure R&D being one thing; hackable code is something quite different sometimes). [that said, sometimes it's hard to even frame the right questions when one is in a brand new area..] -mpg > -Original Message- > From: Stephen Woodbridge [mailto:wood...@swoodbridge.com] > Sent: Monday, March 28, 2011 2:16 PM > To: m...@flaxen.com; OSGeo Discussions > Subject: Re: [OSGeo-Discuss] Finding position based on horizon profile? > > On 3/28/2011 4:48 PM, Michael P. Gerlek wrote: > > Consider the following hypothetical problem: > > > > Assume we have a good elevation data set for a large region of the > > earth -- say, an entire mountain range. Now let's say we have a > > photograph taken from the ground, the horizon of which shows the > > profile of a couple of the mountains in that range. Can you tell me > > where the photograph was taken from? > > > > Any pointers to research in this area would be appreciated. > > Micheal, > > Does this help? > http://www.google.com/#q=matching++"terrain+profile"; > > -Steve ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
[OSGeo-Discuss] Finding position based on horizon profile?
Consider the following hypothetical problem: Assume we have a good elevation data set for a large region of the earth -- say, an entire mountain range. Now let's say we have a photograph taken from the ground, the horizon of which shows the profile of a couple of the mountains in that range. Can you tell me where the photograph was taken from? Any pointers to research in this area would be appreciated. -mpg ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
