Hallöchen! johannes hanika writes:
> On Sun, Jun 2, 2013 at 7:30 PM, Torsten Bronger < > [email protected]> wrote: > >> johannes hanika writes: >> >>> the keystone correction formula uses a perspective correction >>> approach (i.e. image plane x and y shortening is proportional to >>> 1/z in 3d and different for every pixel, much like >>> http://en.wikipedia.org/wiki/Texture_mapping#Perspective_correctness). i >>> don't see why you would need additional constant scaling? >> >> If I apply keystone correction to the plane of the lower-level >> piano keys in <http://wilson.homeunix.com/pc/before.jpg>, the >> result is <http://wilson.homeunix.com/pc/after.jpg>. Thus, the >> aspect ratio of the piano keys is not correct. Even worse, > > what do you mean, correct?i think i don't understand what result you're > after here. I want to have it like this: http://wilson.homeunix.com/pc/correct.jpg In this case, the aspect ratio of the piano keys is approx. 1:6.2, which is the same as if you take a picture with the sensor parallel to the piano keys plane like here: http://wilson.homeunix.com/pc/frontal.jpg In other words, a chessboard photographed with a tilt angle should be transformed into a chessboard with *squares* rather than rectangles. Tschö, Torsten. -- Torsten Bronger Jabber ID: [email protected] or http://bronger-jmp.appspot.com ------------------------------------------------------------------------------ Get 100% visibility into Java/.NET code with AppDynamics Lite It's a free troubleshooting tool designed for production Get down to code-level detail for bottlenecks, with <2% overhead. Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap2 _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
