[PanoTools-devel] adding projections was: Albers Equal Area Conic Projection

 [PanoTools-devel] adding projections was: Albers Equal Area Conic Projection From: Daniel M. German - 2006-12-29 19:29:57 ```Hi Everybody, I like the projection and I will incorporate the code (I just need a few days). It is important also to remember that some projections are special cases of others. For example, oblique projections are a more general projection than "regular ones", but obliques are not necessary because one can rotate the panorama before the projection is made (which is not usually done with the Earth :) In fact, if we allow the specification of the two parallels, the ALbert projection is a general case of the Lamberts (both cylindrical--0,0 I think-- and conic--90,-90). Pablo, what is your opinion in extending the parser with a multi-value parameter? I would think that it will be clearer to have 2 parameters instead of 1. This is because some projections need only one. And this, of course, will affect nona. dmg Michael> Hi Michael> The two parameters are the standard parallels in degrees. The r= ange is=20 Michael> from 90=B0 to -90=B0. Along these these parallels there is no a= ngular and no=20 Michael> scale distortion. The ordering of the parameters has no effect. Michael> Depending on phi1 and phi2 the shape of the projection is diffe= rently=20 Michael> curved. You can also make phi1=3Dphi2. When phi1=3Dphi2=3D90 th= en the=20 Michael> projection is circle. With phi1=3Dphi2=3D-90 the projection is = also a circle=20 Michael> but the other way round (i.e. 90: tripod is in the center, -90:= sky is=20 Michael> in the center). Michael> With phi1=3D-phi2 you get also a circle where the zenith and na= dir are=20 Michael> both located somewhere in the circle. phi1=3D90, phi2=3D0 gets = you a=20 Michael> half-circle. Michael> A few examples: http://mdgrosse.net/pano/albers_-90_-90.jpg http://mdgrosse.net/pano/albers_-90_0.jpg http://mdgrosse.net/pano/albers_0_-60.jpg http://mdgrosse.net/pano/albers_0_10.jpg http://mdgrosse.net/pano/albers_0_60.jpg http://mdgrosse.net/pano/albers_90_-90.jpg http://mdgrosse.net/pano/albers_90_0.jpg http://mdgrosse.net/pano/albers_90_90.jpg http://mdgrosse.net/pano/albers_9_10.jpg Michael> yuval levy wrote: >> --- "Michael Gross (adv)" wrote: >>> I wrote something about the changes in >>> http://mdgrosse.net/pano/albersequalareaconic.txt >>=20 >> thanks! to understand it better, I have a couple of >> questions: >>=20 >> P"60.0 20.0" >>=20 >> are these the two standard parallels? >> ? >>=20 Michael> ---------------------------------------------------------------= ---------- Michael> Take Surveys. Earn Cash. Influence the Future of IT Michael> Join SourceForge.net's Techsay panel and you'll get the chance = to share your Michael> opinions on IT & business topics through brief surveys - and ea= rn cash Michael> http://www.techsay.com/default.php?page=3Djoin.php&p=3Dsourcefo= rge&CID=3DDEVDEV Michael> _______________________________________________ Michael> PanoTools-devel mailing list Michael> PanoTools-devel@... Michael> https://lists.sourceforge.net/lists/listinfo/panotools-devel -- Daniel M. German "If builders built buildings the way computer programmers write programs, the first woodpecker that came along would have destroyed Weinberg's law -> all civilization. " http://turingmachine.org/ http://silvernegative.com/ dmg (at) uvic (dot) ca replace (at) with @ and (dot) with . =20 ```