KPG1_AKERx

Smooths a two-dimensional array using an arbitrary rectangular kernel

Description:

The routine smooths the array A using an arbitrary smoothing kernel, and returns the result in the array B.

Invocation

CALL KPG1_AKERx( IBOX, JBOX, WEIGHT, SAMBAD, WLIM, NX, NY, BAD, VAR, A, B, BADOUT, STATUS )

Arguments

IBOX = INTEGER (Given)
Half-size, in pixels along the x axis, of the box over which the smoothing will be applied (the actual box used has an edge which is 2∗IBOX+1 pixels long). This defines the region within which the smoothing function is non-zero.
JBOX = INTEGER (Given)
Half-size, in pixels along the y axis, of the box over which the smoothing will be applied (the actual box used has an edge which is 2∗JBOX+1 pixels long). This defines the region within which the smoothing function is non-zero.
WEIGHT( 2 ∗ IBOX + 1, 2 ∗ JBOX + 1 ) = ? (Given)
The weighting kernel. It need not be normalised to one, but this is strongly preferred since it reduces the chance of overflows.
SAMBAD = LOGICAL (Given)
If a .TRUE. value is given, then any " bad" pixels in the input array A will be propagated to the output array B (output values will be calculated for all other output pixels). If a .FALSE. value is given, then the WLIM argument is used to determine which output pixels will be bad (if any). This argument is not relevant if BAD is .FALSE..
WLIM = ? (Given)
The minimum weighting that can be used to compute a smoothed output pixel if SAMBAD is .FALSE.. Any output pixels falling short of the specified weight will be set to the bad value (invalid pixels carry no weight, others have Gaussian weights about the central pixel). The value must be greater than 0.0 and should be less than or equal to 1.0. This argument is not used if SAMBAD is .TRUE. or if BAD is .FALSE..
NX = INTEGER (Given)
First dimension of the 2-d array A.
NY = INTEGER (Given)
Second dimension of the 2-d array A.
BAD = LOGICAL (Given)
Whether it is necessary to check for bad pixels in the input array A.
VAR = LOGICAL (Given)
If a .FALSE. value is given for this argument, then smoothing will be performed as if the array supplied (A) is an array of data and the PSF will be used directly as specified. If a .TRUE. value is given, then smoothing will be applied as if the array is an array of variance values associated with an array of data; in this case, the effective PSF will be reduced in width by a factor 2 and the mean output values will be reduced to reflect the variance-reducing effect of smoothing.
A( NX, NY ) = ? (Given)
Array containing the input image to be smoothed.
B( NX, NY ) = ? (Returned)
Array containing the input image after smoothing.
BADOUT = LOGICAL (Returned)
Whether there are bad pixel values in the output array.
STATUS = INTEGER (Given and Returned)
The global status.

Notes: