This paper presents a new approach to non-rigid elastic registration. The method is applied to hyper spectral imaging
data for the automatic quality control of decorative foils which are subject to deformation during lamination. A new image
decimation procedure based on Savitzky-Golay smoothing is presented and applied in a multiresolution pyramid. Modified
Fourier basis functions implemented by projection onto the orthogonal complement of a truncated Gram polynomial basis
are presented. The modified functions are used to compute spectra whereby the Gibbs error associated with local gradients
in the image are reduced. The paper also presents the first direct linear solution to weighted tensor product polynomial
approximation. This method is used to regularize the patch coordinates, the solution is equivalent to a Galerkin type
solution to a partial differential equations. The new solution is applied to published standard data set and to data acquired
in a production environment. The speed of the new solution justifies explicit reference: the present solution implemented
in MATLAB requires approximatly 1.3s to register an image of size 800 ×× 500 pixels. This is approximately a factor 10
to 100 faster than previously published results for the same data set.
Recently specialized robots were introduced to perform the task of
inspection and repair in large cylindrical structures such as
ladles, melting furnaces and converters. This paper reports on the
image processing system and optical servoing for one such a robot.
A panoramic image of the vessels inner surface is produced by
performing a coordinated robot motion and image acquisition. The
level of projective distortion is minimized by acquiring a high
density of images. Normalized phase correlation calculated via the
2D Fourier transform is used to calculate the shift between the
single images. The narrow strips from the dense image map are then
stitched together to build the panorama. The mapping between the
panoramic image and the positioning of the robot is established
during the stitching of the images. This enables optical feedback.
The robots operator can locate a defect on the surface by
selecting the area of the image. Calculation of the forward and
inverse kinematics enable the robot to automatically move to the
location on the surface requiring repair. Experimental results
using a standard 6R industrial robot have shown the full
functionality of the system concept. Finally, were test
measurements carried out successfully, in a ladle at a temperature
of 1100° C.