Аннотация
This paper presents a new algorithm which can be used to register
images of the same or different modalities, e.g., images with multiple
channels, such as X-rays, temperature or elevation, or simply images
of different spectral bands. In particular, a correlation-based scheme
is used, but instead of gray values, it correlates numbers formulated
by different combinations of the extracted local Walsh coefficients
of the images. Each image patch is expanded in terms of Walsh basis
functions. Each Walsh basis function can be thought of as measuring
a different aspect of local structure, e.g., horizontal edge, corner,
etc. The coefficients of the expansion, therefore, can be thought
of as dense local features, estimating at each point the degree of
presence of, for example, a horizontal edge, a corner with contrast
of a certain type, etc. These coefficients are normalized and used
as digits in a chosen number system which allows one to create a
unique number for each type of local structure. The choice of the
basis of the number system allows one to give different emphasis
to different types of local feature (e.g., corners versus edges),
and, thus, the method we present forms a unified framework in terms
of which several feature matching methods may be interpreted. The
algorithm is compared with wavelet and contour based approaches,
using simulated and real images. The two images are assumed to differ
from each other by a rotation and a translation only.
Линки и ресурсы
тэги
- Walsh
- approach
- approach,
- bands,
- basis
- channels,
- coefficients,
- contour-based
- correlation
- correlation-based
- feature
- functions,
- image
- local
- matching
- matching,
- methods,
- multiple
- number
- patch,
- registration,
- scheme,
- spectral
- system,
- transform,
- transforms
- wavelet-based