On Sat, 20 Mar 2010 11:50:13 +0200, John Smith <deltafoxtrot...@gmail.com> wrote:
> On 20 March 2010 19:42, Teemu Koskinen <teemu.koski...@mbnet.fi> wrote: >> I wish I had known that the Yahoo aerial images are not rectified, as I >> blindly went and "corrected" all the roads in my neighborhood by moving >> them to coincide with the aerial images. In reality they already were in >> the correct position as they were drawn from more accurate gps-traces. > > Someone mentioned this a while back, in terms of editors storing > corrected image positions centrally. > That only helps if the images are just offset by some amount, it doesn't help at all if they are warped, rotated etc. See eg. the centre of Helsinki: http://elanor.mine.nu/daeron/wavy.jpg All the red lines are completely straight in reality. The whole Helsinki area is full of similar errors in the Yahoo aerial images. Teemu Koskinen _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
