Standards /

WCPS-Manual / rangeConstructorExpr

The rangeConstructorExpr, an n-ary induced operation, allows to build coverages with compound range structures. To this end, coverage range field expressions enumerated are combined into one coverage. All input coverages must match wrt. domains and CRSs.

It is allowed to list an input coverage more than once.

Let

n be an integer with n ≥ 1,
C1, ... , Cn be coverageExprs,
f1, ... , fn be fieldNames
where

fi ∈ rangeFieldNames(Ci),
imageCrs(Ci) = imageCrs(Cj),
imageCrsDomain(Ci) = imageCrsDomain(Cj),
crsSet(Ci) = crsSet(Cj),
generalDomain(Ci,ai,Ci) = generalDomain(Cj,aj,Cj)
for all ai ∈ axisSet(Ci), aj ∈ axisSet(Cj), Ci ∈ crsSet(Ci), Cj ∈ crsSet(Cj).

Then,

for any coverageExpr C'
where

  C' =  { C1 , ... , Cn }
  

C2 is defined as follows:

Example

The expression below does a false color encoding by combining near-infrared, red, and green bands into a 3-band image of 8-bit channels each, which can be visually interpreted as RGB:

{ (char) L.nir, (char) L.red, (char) L.green }

The following expression transforms a greyscale image G containing a single range field panchromatic into an RGB-structured image:

{ G.panchromatic, G.panchromatic, G.panchromatic }