Hi Philipp, very nice! thank you! Dont worry about the house advertisement. That was exactly i was looking for. Unfortunately for some data i only have a set op up and down scans to calculate the drift velocity. In your paper it says that "mixing up and down images might lead to results in incorrect drift velocities". Would that be too bad if i do anyway? How were your experiences?
How did you solve the problem with the loss of some parts of the image due to the polynomial transformation? Best regards, Holger Am 07.12.2012 03:26, schrieb Philipp Rahe: > 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 ------------------------------------------------------------------------------ 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
