Hello Holger, we ran into the same problem some time ago - with the assumption of linearity it's totally fine to linear 'distort' the image in Gwyddion based on the measured lateral drift velocities. We calculated the necessary coefficients for Gwyddion in [J. Vac. Sci. Technol. B 28 (2010) C4E31], Eq 28 to 31. (Sorry for the house advertising)
Good luck, Philipp David Nečas (Yeti) schrieb: > On Thu, Dec 06, 2012 at 03:32:15PM -0200, holgermw wrote: >> Sorry, i was not explaining well. Actually X and X' should be vectors. X >> describes a vector for each pixel of the original image and X' a vector >> after the drift compensation, while the vector Vd*t is moving the image >> opposite to the direction of the drift. The absolute value of the >> movement is depending on the time t, which depends on the columns, lines >> and scan velocity. > > Then I would say you need the inverse transformation, i.e. specify how > to calculate X from X', to compensate the drift using Polynomial > Distortion. > >> For me seems that this transformation and the reverse transformation >> should both be possible, but maybe i did not understand you well. > > They should be both possible for physically meaningful transformations > (more or less). > > But you can enter arbitrary polynomials (up to some degree) and these > are not invertible in general. > >> Maybe i also do things too complicated. How do you usually compensate a >> linear drift from an spm image? Sorry for asking so basic question. > > If you cannot use Compensate Drift that attempts to compensate drift in > the direction of the fast axis (the most common problem) by correlating > neighbour lines then general polynomial distortion is probably the only > other possibility Gwyddion offers. > > Regards, > > Yeti > > > ------------------------------------------------------------------------------ > LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial > Remotely access PCs and mobile devices and provide instant support > Improve your efficiency, and focus on delivering more value-add services > Discover what IT Professionals Know. Rescue delivers > http://p.sf.net/sfu/logmein_12329d2d > _______________________________________________ > Gwyddion-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/gwyddion-users ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Gwyddion-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gwyddion-users
