Re: [Talk-GB] Stratford Imagery
On Fri, 28 May 2010 09:47:06 + (UTC) Ed Avis wrote: Hello Ed, > Apparently I have unlimited storage on Flickr, so I could do it. With a proviso; There is a restriction on the _free_ Flickr accounts in that only a certain number of images (200, IIRC) are publicly viewable. So, eventually, those images would become unavailable when a sufficient number have been uploaded. Nothing gets deleted, though. If you've upgraded to a paid for account, that restriction doesn't apply. -- Regards _ / ) "The blindingly obvious is / _)radnever immediately apparent" Success defined by acquisition stinks Money is Not Our God - Killing Joke ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford Imagery
John McKerrell writes: >>>Since sometime last summer I've been hosting the imagery that was >>>photographed from a plane over Stratford. >it's 39Gb for all the originals and the resized smaller versions. Apparently I have unlimited storage on Flickr, so I could do it. Maybe the smaller versions would not be needed since Flickr can resize images itself. -- Ed Avis ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford Imagery
On 27 May 2010, at 10:55, Ed Avis wrote: > John McKerrell writes: > >> Since sometime last summer I've been hosting the imagery that was >> photographed >> from a plane over Stratford. > > Perhaps I could upload them to my Flickr account? How big is the data in > total? Yes I should have mentioned that bit, it's 39Gb for all the originals and the resized smaller versions. John ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford Imagery
John McKerrell writes: >Since sometime last summer I've been hosting the imagery that was photographed >from a plane over Stratford. Perhaps I could upload them to my Flickr account? How big is the data in total? -- Ed Avis ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
[Talk-GB] Stratford Imagery
Hi Since sometime last summer I've been hosting the imagery that was photographed from a plane over Stratford. I'm going to be getting rid of the server that is hosting this before the end of this month. My new server has plenty of disk space and I don't think these images are being downloaded much so I could probably just switch them over unless anyone else particularly wants to take responsibility for them? I do have a local copy so they won't be lost if I don't do anything. If you do want to make a copy then please mention it on the list, the server should have plenty of spare bandwidth as it's not doing much right now but I'd rather avoid tens of people all trying to download all the imagery. So.. if you have any particular thoughts about what should be done with this let me know. Like I say I can probably host them again if necessary but even if I do that there'll be lots of links that need updating (would need to be a hostname this time rather than an IP), or if someone wants to take responsibility please speak up. John ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford imagery
> We should try to get this large redundancy when flying again So what you are saying is that I should take *more* photos ... noone has ever said that to me before ... there is always a first for everything. The outcomes that I'm hearing from this is -- higher altitude; more image overlap; the less oblique the better Areas where I put effort into that arn't really so important: lens geometry (i chose a prime lense that I knew was very planar); sheer resulution, I could have taken a slightly higher altitude without a problem. Question -- is it within our licencing to recitfy to yahoo imagery? because if it is, we could use SIFT to automate it. JR 2009/12/15 Tim Waters : > 2009/12/10 Peter Miller : >> >> On 10 Dec 2009, at 14:18, Andy Allan wrote: >> >>> Hi Peter >>> >>> On Wed, Dec 9, 2009 at 9:20 PM, Peter Miller >> > wrote: >>> Thanks Andy, your wiki page is very useful and it is also good to see the imagery in Potlatch. Is the location of image encoded in the image somehow, or how else does PotLatch know where to load it? >>> >>> They are made into 256x256 tiles, with the same z/x/y.png notation as >>> the main tileserver. It's the same way that the out-of-copyright maps >>> work too. The !'s in the url on the wikipage are placeholders for >>> potlatch to put in the tile numbers. For example, >>> >>> http://gravitystorm.dev.openstreetmap.org/imagery/stratford/14/8113/5397.png >> >> Thanks. That is very neat. >> >>> When I tried warping the images I did feel that the algorithm used by warper was possibly a bit suspect - the warping suddenly went completely wrong as one added more control points in a rather counter-intuitive way. >>> >>> I'd discussed this with a few people over beers, and the problem >>> appears to be that the warper's algorithm is assuming that you start >>> with a fairly "flat" image, and doesn't take into account that the >>> plane of the image might not be horizontal. It's for warping maps, >>> after all, and we're semi-abusing it by warping photos instead. An >>> extra control point or two can send it off wildly (as it tries to >>> figure out how exactly a map sheet would end up stretched so) and of >>> course it gets worse the further from vertical the photo is. >>> >> >> So there is certainly a nice job for someone to sort out a suitable >> algorithm that will work in practical situations when one doesn't >> necessarily even have height data and certainly has distortions of >> various sorts. The idea of associating 'ways' on the image to 'ways' >> on the map sounds very neat assuming that one has a skeleton road >> structure in place (which one could of course get from old OS maps if >> necessary). I think it would then work a treat - certainly much better >> than Warper currently manages. > > I also agree would be great to be able to use linear features to > rectifty, it's on my list! > > But I just thought I'd make you aware of the "advanced options" > feature on Warper - by default, the algorithm changes based on the > number of control points - you can override this behaviour. > > [You can also have a go at using the "Thin Plate Spline" method, which > is best with lots of points - although ymmv and there may be a bug > (mainly because no one uses it!). But essentially it gives a better > warp when theres more points and treats the points as fixed - worth > trying it offline with the command line GDAL tools if you have the > time. ] > > **For all methods, the more points, the better.** > > Orthorectification is another thing though - thank god the photo's > were in a relatively flat area! > > More generally as you know, in the world of aerial photography, > there's usually extensive overlap (up to 60%?) for photos over areas > and so you really shouldn't worry if 20% of the oblique image is > unusable. We should try to get this large redundancy when flying again > :) > > > Cheers, > > Tim > > ___ > Talk-GB mailing list > Talk-GB@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-gb > ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford imagery
2009/12/10 Peter Miller : > > On 10 Dec 2009, at 14:18, Andy Allan wrote: > >> Hi Peter >> >> On Wed, Dec 9, 2009 at 9:20 PM, Peter Miller > > wrote: >> >>> Thanks Andy, your wiki page is very useful and it is also good to >>> see the >>> imagery in Potlatch. Is the location of image encoded in the image >>> somehow, >>> or how else does PotLatch know where to load it? >> >> They are made into 256x256 tiles, with the same z/x/y.png notation as >> the main tileserver. It's the same way that the out-of-copyright maps >> work too. The !'s in the url on the wikipage are placeholders for >> potlatch to put in the tile numbers. For example, >> >> http://gravitystorm.dev.openstreetmap.org/imagery/stratford/14/8113/5397.png > > Thanks. That is very neat. > >> >>> When I tried warping the images I did feel that the algorithm used >>> by warper >>> was possibly a bit suspect - the warping suddenly went completely >>> wrong as >>> one added more control points in a rather counter-intuitive way. >> >> I'd discussed this with a few people over beers, and the problem >> appears to be that the warper's algorithm is assuming that you start >> with a fairly "flat" image, and doesn't take into account that the >> plane of the image might not be horizontal. It's for warping maps, >> after all, and we're semi-abusing it by warping photos instead. An >> extra control point or two can send it off wildly (as it tries to >> figure out how exactly a map sheet would end up stretched so) and of >> course it gets worse the further from vertical the photo is. >> > > So there is certainly a nice job for someone to sort out a suitable > algorithm that will work in practical situations when one doesn't > necessarily even have height data and certainly has distortions of > various sorts. The idea of associating 'ways' on the image to 'ways' > on the map sounds very neat assuming that one has a skeleton road > structure in place (which one could of course get from old OS maps if > necessary). I think it would then work a treat - certainly much better > than Warper currently manages. I also agree would be great to be able to use linear features to rectifty, it's on my list! But I just thought I'd make you aware of the "advanced options" feature on Warper - by default, the algorithm changes based on the number of control points - you can override this behaviour. [You can also have a go at using the "Thin Plate Spline" method, which is best with lots of points - although ymmv and there may be a bug (mainly because no one uses it!). But essentially it gives a better warp when theres more points and treats the points as fixed - worth trying it offline with the command line GDAL tools if you have the time. ] **For all methods, the more points, the better.** Orthorectification is another thing though - thank god the photo's were in a relatively flat area! More generally as you know, in the world of aerial photography, there's usually extensive overlap (up to 60%?) for photos over areas and so you really shouldn't worry if 20% of the oblique image is unusable. We should try to get this large redundancy when flying again :) Cheers, Tim ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford imagery
On Thu, Dec 10, 2009 at 2:40 PM, Peter Miller wrote: > The thread is here in case you want to get involved:- > http://lists.openstreetmap.org/pipermail/talk-gb-westmidlands/2009-December/000398.html I've had a quick read of that, forgive me for not signing up to yet another mailing list :-) I'd recommend you put the imagery on dev.openstreetmap.org first, and if/when that becomes a problem look to host elsewhere. It seems completely overkill trying to buy, run and host yet another server when it's just some imagery to be served from disk! Dev has oodles of space and capacity so we may as well make good use of that. Save the west midlands cash for buy imagery. Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford imagery
Peter Miller wrote: > > I was wondering if 'type approval' for powered hang-gliders allows for > bolt-on vertical cameras. Thinking about it I am going to worry a bit > more about hang glider pilots dropping phones and cameras etc next > time they are wandering about overhead! > A powered hang-glider is a microlight and subject to strict CAA rules. Modifications that might allow a bolted-on object (like a camera) to fall off if the fixing was not done properly are outside the approval of such an aircraft. The only way to operate such an aircraft leaves very little opportunity to modify it in the UK. You might mean a powered paraglider. I wouldn't want to fly a powered paraglider over a built up area, where would you land if (when) your motor stops? The glide ratio is terrible, so the distance you could glide is quite short. Cheers, Chris ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford imagery
On 10 Dec 2009, at 14:18, Andy Allan wrote: > Hi Peter > > On Wed, Dec 9, 2009 at 9:20 PM, Peter Miller > wrote: > >> Thanks Andy, your wiki page is very useful and it is also good to >> see the >> imagery in Potlatch. Is the location of image encoded in the image >> somehow, >> or how else does PotLatch know where to load it? > > They are made into 256x256 tiles, with the same z/x/y.png notation as > the main tileserver. It's the same way that the out-of-copyright maps > work too. The !'s in the url on the wikipage are placeholders for > potlatch to put in the tile numbers. For example, > > http://gravitystorm.dev.openstreetmap.org/imagery/stratford/14/8113/5397.png Thanks. That is very neat. > >> When I tried warping the images I did feel that the algorithm used >> by warper >> was possibly a bit suspect - the warping suddenly went completely >> wrong as >> one added more control points in a rather counter-intuitive way. > > I'd discussed this with a few people over beers, and the problem > appears to be that the warper's algorithm is assuming that you start > with a fairly "flat" image, and doesn't take into account that the > plane of the image might not be horizontal. It's for warping maps, > after all, and we're semi-abusing it by warping photos instead. An > extra control point or two can send it off wildly (as it tries to > figure out how exactly a map sheet would end up stretched so) and of > course it gets worse the further from vertical the photo is. > So there is certainly a nice job for someone to sort out a suitable algorithm that will work in practical situations when one doesn't necessarily even have height data and certainly has distortions of various sorts. The idea of associating 'ways' on the image to 'ways' on the map sounds very neat assuming that one has a skeleton road structure in place (which one could of course get from old OS maps if necessary). I think it would then work a treat - certainly much better than Warper currently manages. >> At present I feel that it was a great experiment, but that we >> either need >> much more vertical images which will be hard to achieve without a >> plane >> without specialist equipment or we need a smarter warper. > > There were plenty of photos that were vertical enough, just > interspersed amongst many more that weren't. It's good that we know > now that it's more helpful to wait until the plane is banking around > rather than trying to get as many photos as possible, since the angled > ones just make the processing more of a faff. In saying that, a warper > aware of the (approximate) angle of capture would help too. I was wondering if 'type approval' for powered hang-gliders allows for bolt-on vertical cameras. Thinking about it I am going to worry a bit more about hang glider pilots dropping phones and cameras etc next time they are wandering about overhead! > >> We also need to compare the cost of our own imagery with the cost of >> purchasing satellite imagery and I feel that purchased imagery will >> often >> win (from $14 per sq km). The West Midlands guys are getting >> organised to >> host purchased photography for that area. > > Awesome. If anyone needs help processing imagery that's been > purchased, let me know. The thread is here in case you want to get involved:- http://lists.openstreetmap.org/pipermail/talk-gb-westmidlands/2009-December/000398.html Regards, Peter > > Cheers, > Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford imagery
Hi Peter On Wed, Dec 9, 2009 at 9:20 PM, Peter Miller wrote: > Thanks Andy, your wiki page is very useful and it is also good to see the > imagery in Potlatch. Is the location of image encoded in the image somehow, > or how else does PotLatch know where to load it? They are made into 256x256 tiles, with the same z/x/y.png notation as the main tileserver. It's the same way that the out-of-copyright maps work too. The !'s in the url on the wikipage are placeholders for potlatch to put in the tile numbers. For example, http://gravitystorm.dev.openstreetmap.org/imagery/stratford/14/8113/5397.png > When I tried warping the images I did feel that the algorithm used by warper > was possibly a bit suspect - the warping suddenly went completely wrong as > one added more control points in a rather counter-intuitive way. I'd discussed this with a few people over beers, and the problem appears to be that the warper's algorithm is assuming that you start with a fairly "flat" image, and doesn't take into account that the plane of the image might not be horizontal. It's for warping maps, after all, and we're semi-abusing it by warping photos instead. An extra control point or two can send it off wildly (as it tries to figure out how exactly a map sheet would end up stretched so) and of course it gets worse the further from vertical the photo is. > At present I feel that it was a great experiment, but that we either need > much more vertical images which will be hard to achieve without a plane > without specialist equipment or we need a smarter warper. There were plenty of photos that were vertical enough, just interspersed amongst many more that weren't. It's good that we know now that it's more helpful to wait until the plane is banking around rather than trying to get as many photos as possible, since the angled ones just make the processing more of a faff. In saying that, a warper aware of the (approximate) angle of capture would help too. > We also need to compare the cost of our own imagery with the cost of > purchasing satellite imagery and I feel that purchased imagery will often > win (from $14 per sq km). The West Midlands guys are getting organised to > host purchased photography for that area. Awesome. If anyone needs help processing imagery that's been purchased, let me know. Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford imagery
On 9 Dec 2009, at 18:39, Andy Allan wrote: > On Tue, Nov 10, 2009 at 2:48 PM, Andy Allan > wrote: >> Hi All, >> >> Where did we end up with the Stratford imagery in the end? When I >> left >> things, I'd made a layer containing about 7 images, made tiles from >> them, and stuck them online. > > I guessed from the silence that nobody had any further plans. :-) > Having some spare time on my hands right now (ahem!) I've grabbed as > many warped images off of mapwarper and made a new tile layer, and > I've added some more documentation to the wiki. > > http://wiki.openstreetmap.org/wiki/Stratford-upon-Avon/Imagery > > Anyone fancy collecting more imagery for any other towns? Thanks Andy, your wiki page is very useful and it is also good to see the imagery in Potlatch. Is the location of image encoded in the image somehow, or how else does PotLatch know where to load it? When I tried warping the images I did feel that the algorithm used by warper was possibly a bit suspect - the warping suddenly went completely wrong as one added more control points in a rather counter- intuitive way. At present I feel that it was a great experiment, but that we either need much more vertical images which will be hard to achieve without a plane without specialist equipment or we need a smarter warper. Someone suggested at the time that it would be good to have a warper where one could lay down a way on the imagery and associate it with a way on the map - that could be hugely beneficial. Anyone fancy giving it a go? We also need to compare the cost of our own imagery with the cost of purchasing satellite imagery and I feel that purchased imagery will often win (from $14 per sq km). The West Midlands guys are getting organised to host purchased photography for that area. Regards, Peter > > Cheers, > Andy > > ___ > Talk-GB mailing list > Talk-GB@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Stratford imagery
On Tue, Nov 10, 2009 at 2:48 PM, Andy Allan wrote: > Hi All, > > Where did we end up with the Stratford imagery in the end? When I left > things, I'd made a layer containing about 7 images, made tiles from > them, and stuck them online. I guessed from the silence that nobody had any further plans. :-) Having some spare time on my hands right now (ahem!) I've grabbed as many warped images off of mapwarper and made a new tile layer, and I've added some more documentation to the wiki. http://wiki.openstreetmap.org/wiki/Stratford-upon-Avon/Imagery Anyone fancy collecting more imagery for any other towns? Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
[Talk-GB] Stratford imagery
Hi All, Where did we end up with the Stratford imagery in the end? When I left things, I'd made a layer containing about 7 images, made tiles from them, and stuck them online. You can see them in action in potlatch at one of these URLs (both are the same): http://bit.ly/8yJhG http://www.openstreetmap.org/edit?lat=52.191248&lon=-1.701483&zoom=18&tileurl=http://andy.sandbox.cloudmade.com/tiles/stratford/!/!/!.png Did anyone make further progress? I know there was a lot of discussion about alternative approaches - did any work out? I don't really have the time or inclination to warp more images, but if someone else has been diligently doing so I'd love to take your images and make an imagery layer out of them, the same as I recently did for the Philippines. Has anyone done so? Ideally, I'd like a list of urls to fetch warped tiffs from, in the order (best to worst?) of priority for laying them on top of each other. If the project is now "done" (i.e. nobody has any plans for more) then I'll round off the documentation on the wiki. http://wiki.openstreetmap.org/wiki/Stratford-upon-Avon Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
