How to Manipulate
Principal Components Transformation
Learn
more about Principal Components Transformation
Before executing the
Principal Components function you can analyze statistical parameters of the
selected bands. These parameters might refer to the image whole area or just a selected portion.
How to see the
parameters of the whole image:
-
click on Image and Principal Components... to open the correspondent window;
-
click on Infolayers
list to select the desired bands (at least
two). Notice that only the infolayers (bands) of same resolution and bounding
box will be presented on the list;
-
in
Sample click on Image;
-
click on Acquire. In
this case it is not necessary to have the image visible on the screen. It
is enough to have the infolayer, correspondent
to the group of bands to be analyzed, active. The
image
whole area will be used;
-
click on Parameters... .The window "Principal
Components Parameters"
is presented. The following parameters are shown: Mean and
Variance
for each band, Eigenvalue and Percentage of
information for
each component,
Covariance Matrix, Correlation Matrix and Eigenvectors Matrix.
How to see the
parameters of a selected area on the image:
-
click on Image and Principal Components... to open the correspondent window;
-
click on Infolayers
list to select the desired bands (at least
two). Notice that only the infolayers (bands) of same resolution and bounding
box will be presented on the list;
-
in
Sample click on Cursor;
-
mark
the region on the image using the Zoom
Cursor (
). Click (LB) on the top left corner, drag the
mouse to where you want and then click again (LB);
-
click on Acquire.
Notice that the selected regions are highlighted. To select other
regions, proceed as described above. In this case, it is necessary to
have the image visible on the screen before acquiring the samples,
otherwise the message "There is no active image on the screen" will be presented;
-
click on Parameters... .The window "Principal
Components Parameters"
is presented.
NOTE:
After analyzing the statistical parameters you can execute the
transformation. It is not required to go through the "Principal Components Parameters" interface first.
Performing
Principal Components
Transformation
:
-
click on Image and Principal Components... to open the correspondent window;
-
click on Infolayers
list to select the desired bands (at least
two). Notice that only the infolayers (bands) of same resolution and bounding
box will be presented on the list;
-
in
Sample, click
on Cursor if
an area is selected, or Image for the whole image;
-
click on Output Image e type
the name which will be used as a prefix to generate the output images. For
instance, if you select two bands and the output image is named"Comp", the outcome will be
"Comp-PC1" and "Comp-PC2";
-
click on Apply. The
created images (components) are presented on the "Control Panel" in the same category of the selected bands.
See also:
Image Processing techniques
Image Processing Menu
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