I second that, using a precomputed mapping will be the most useful algorithm. Because normally, everybody is doing the reverse mapping (undistortion by calculating the distorted positions from the undistorted ones and doing a reverse mapping) and avoids the other way around like the devil runs from the holy water.
What could be a feasible solution too: Calculate the distorted points from the undistorted ones and interpolate between the supporting points with a 2nd order polynomial. Maybe you even could reduce the number of supporting points by calculating only a sparse mapping between undistorted and distorted points. Basically doing a piecewise polynomial interpolation. Michael Am 17.04.2012 00:43, schrieb Jonathan Merritt: > Reading that paper (Vass and Perlaki), they present a very good > solution. > If you're running the inverse transformation on a sequence of > frames, all > of which have the same distortion parameters, then just compute the > inverse > transformation once ("slow"), and cache the result. Then do a > look-up > using either exact values or some kind of fast interpolation for all > of > your movie frames. > > They also describe using Newton's method to compute the (xd, yd) => > (x,y) > transformation, as I suggested. Since these guys have already looked > at > this problem, I suspect that the algebraic inverse transformation is > probably very long and painful. > > Even if your distortion parameters are varying, you could also speed > up the > process by using the solution from the previous frame as the staring > point > for your Newton iteration of the next frame. > > On Mon, Apr 16, 2012 at 4:06 PM, Dan Eicher <d...@trollwerks.org> > wrote: >> >>> These guys describe a fast preview mode (if that's the problem): >>> >>> http://www.vassg.hu/pdf/vass_gg_2003_lo.pdf >>> >>> ...not that I understand the math behind it. >>> >>> Dan >>> _______________________________________________ >>> Bf-committers mailing list >>> Bf-committers@blender.org >>> http://lists.blender.org/mailman/listinfo/bf-committers >>> >> >> > _______________________________________________ > Bf-committers mailing list > Bf-committers@blender.org > http://lists.blender.org/mailman/listinfo/bf-committers _______________________________________________ Bf-committers mailing list Bf-committers@blender.org http://lists.blender.org/mailman/listinfo/bf-committers