pregistrationPDE

Computes the displacement field between two input images.

Synopsis

pregistrationPDE smoothness precision [im_in1|-] [im_in2|-] [im_out|-]

Description

pregistrationPDE estimates the 2D displacement field im_out between the two images im_in1 and im_in2. The field is calculated from im_in1 to im_in2.

The displacement field is based on the minimization of the following criteria:

   E(U) = integral(|I1(p)-I2(p+U)| + smoothness*Laplac(U)).

Such minimization is done by PDE descent with different image scales.

The result is a multispectral image with two bands. The first band corresponds to x-component of the displacement vector and the second band to the y-component. This vector field can be drawn with the operator pplotquiver.

Parameters

smoothness is a real value between [0..1] which controls the regularity of the field. The value 0 corresponds to no regularity, 0.1 to an average regularity and 0.9, to a strong regularity (quasi-constant field). If the displacement is known as rigid (eg. translation) a high smoothness value is recommended. When the displacement is known as non rigid a low smoothness value is recommended.
precision is a real value which defines the precision factor. The higher is the precision, the longer is the computing time. A typical value is 0.9.

Inputs

im_in1 a 2D image.
im_in1 a 2D image (same type and same size as im_in1).

Outputs

im_out a 2D multispectral image.

Result

Returns SUCCESS or FAILURE.

Examples

Displays the vector field of a translation of the tangram.pan image:

   ptranslation 0 10 tangram.pan tangram1.pan
   pregistrationPDE 0.1 0.9 tangram.pan tangram1.pan a.pan
   pplotquiver 800 800 10 -20 a.pan out.pan

C++ prototype

Errc PRegistrationPDE( const Imx2d &ims1, const Imx2d &ims2, Img2duc &imd, Float smoothness, Float precision );

Version française

Estimation du champ de déplacement entre deux images.

Important notice

The source code of this Pandore operator is governed by a specific Free-Software License (the CeCiLL License), also applying to the CImg Library. Please read it carefully, if you want to use this module in your own project (file CImg.h).

IN PARTICULAR, YOU ARE NOT ALLOWED TO USE THIS PANDORE MODULE IN A CLOSED-SOURCE PROPRIETARY PROJECT WITHOUT ASKING AN AUTHORIZATION TO THE CIMG LIBRARY AUTHOR ( http://www.greyc.ensicaen.fr/~dtschump/ )

Author: D. Tschumperlé