×

You are using an outdated browser that does not fully support the intranda viewer.
As a result, some pages may not be displayed correctly.

We recommend you use one of the following browsers:

Full text

Title
Fusion of sensor data, knowledge sources and algorithms for extraction and classification of topographic objects
Author
Baltsavias, Emmanuel P.

International Archives of Photogrammetry and Remote Sensing, Vol. 32, Part 7-4-3 W6, Valladolid, Spain, 3-4 June, 1999
Int(
26
3.3. Matching-Based Coregistration (MBC)
3.3.1. Method
Matching-based coregistration is a general technique to match
geometrically images or images and maps, independently of
their imaging geometry or projection in case of geocoded
datasets. An automatic image matching procedure is applied
(pixel-by-pixel or at coarser intervals) between an input image
and a reference image in order to find corresponding points in
the two images. Therefore, automated image matching is the key
tool for this type of coregistration. The scheme of MBC is
shown in Figure 7 for an input image in its original geometry
and a reference image given in map/ground geometry, e.g. an
ortho-image.
A general workflow of the MBC procedure is shown in Figure
8. It comprises the following processing steps:
1. An automatic image matching procedure is applied to the
image pair to be registered. The output of this procedure is a
so-called disparity map, which shows the shift vectors
between reference image and input image pixel co
ordinates. In order to increase the performance of the image
matching, the following pre-processing steps may be
applied to the data:
• radiometric equalisation in case that the images are
radiometrically different, as is often the case for
multisensor and multitemporal images;
• coarse geometric registration through measurement of
a few tie-points in case that the images are significantly
different in geometry.
Both steps can be done implicitly inside the matching
procedure.
2. In a second step the disparity vectors resulting from image
matching are used to resample the input image to the
reference image geometry.
3.3.2. Application Areas of MBC
Areas of application of the MBC technique include:
1. Registration of multitemporal and multisensor images to
the geometry of a selected reference image.
2. Fine-registration of geocoded multitemporal and
multisensor images in case that there are still obvious
mismatches between the individual images after geocoding.
In such cases, even small geolocation errors may disturb
further applications.
3. MBC may also be used to support fully automatic
geocoding without any operators interaction. For that, an
image may first be coarsely geocoded using an initial
(coarse) parametric model (or even a polynomial
rectification). In a second step, this coarse product may be
geometrically refined using coregistration to an already
geocoded image.
Automatic image matching may also be applied in order to
check the correspondence of any registered or geocoded images.
The disparity vectors, which are achieved for such data will
provide a neutral quality measure for the correspondence of the
data, which obviously should be acceptably small.
Grey value
3.4. i
Automat
to the ne
radiomei
matching
and used
Researcf
pixel m2
moved c
the resp
differenc
or featur
The ma
product
matching
is defin
coefficie
found in
method,
various 1
image, ii
the searc
minimur
correspo
in Paa:
backmat
be applit
3.5. i
Methods
Digital I
multisen
Buchroit
also usei
been de\
During t
image g
Remote
Researcl
geometr
images.
ERDAS,
• Gee
acq
• Inte
par;
• Hig
• Ste:
ster
• Gei
froi
• SA
pha
• DE