public class NavigationOffsetEstimator
extends java.lang.Object
NavigationOffsetEstimator
class uses image and
land mask data to estimate the navigation error in a small tile of
coastal image data. Success of the estimation is largely dependent
on the separability of the image data into two classes: land and
water. A good class separation is achieved when the pixels in each
class differ significantly, such as for a daytime scene of low
albedo water pixels and high albedo land pixels, or a high thermal
contrast scene at night. The class separation is done using a
histogram splitting method, and then the navigation error is
determined by "shifting" the image data around to find the maximum
correlation with a precomputed land mask.Constructor and Description |
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NavigationOffsetEstimator() |
Modifier and Type | Method and Description |
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int[] |
getOffset(Grid grid,
EarthTransform trans,
EarthLocation earthLoc,
int boxHeight,
int boxWidth,
int searchLevel)
Gets the offset estimate for the specified earth location.
|
void |
setMinCorrelation(double corr)
Sets the minimum image correlation value for successful offset
estimation.
|
void |
setMinFraction(double frac)
Sets the minimum class pixels as a fraction of total image
pixels.
|
void |
setMinStdevDist(double dist)
Sets the minimum distance in standard deviation units for
successful histogram splitting.
|
void |
setVerbose(boolean flag)
Sets the verbose flag to print verbose output during estimation.
|
public void setMinStdevDist(double dist)
dist
- the new minimum distance in standard deviation units.public void setMinCorrelation(double corr)
corr
- the new minimum correlation value in the range
[0..1].public void setMinFraction(double frac)
frac
- the new minimum class fraction in the range
[0..1].public void setVerbose(boolean flag)
public int[] getOffset(Grid grid, EarthTransform trans, EarthLocation earthLoc, int boxHeight, int boxWidth, int searchLevel)
grid
- the grid to use for data values.trans
- the earth transform for the data grid.earthLoc
- the center location for the navigation box.boxHeight
- the navigation box height in data dimensions.boxWidth
- the navigation box width in data dimensions.searchLevel
- the search level, starting from 0. A search
level of 0 searches using only image data inside the navigation
box. A search level of n increases the search area to (n+1)^2
times the size of the navigation box, with a corresponding
increase in algorithm run time.