Use case: From an elevation data set, extract a subset given by a bounding box and deliver either GIS-ready (with values unchanged) or visualization-ready (with height translated into color codes)
Dataset:ICGC Elevation data set; coverage created from ASCII file and separate XML file with INSPIRE metadata
Service used: OGC WCS, WCPS
Notes: First, a WCS GetCoverage request performs subsetting and retrieval of the original data. While this is good for a GIS it does not display nicely. Therefore, a WCPS query is provided in addition which stretches values into better visible grayscale. WCPS queries like this typically are generated automatically by some client or script, users will not notice them.
Next, we do the same with WCPS - just subsetting:
But WCPS can do much more, such as recoding the values: