Example 1 - The expression below computes a 256-bucket histogram over band b of some coverage $c of unknown domain extent and dimension

Example 2 - The expression below creates a 2D geo-referenced coverage decoded() from an input TIFF file submitted as a positional parameter in WCPS query. The demo will download the tiff file from this link and submit it along with the WCPS example query when you click on the "Run Query" button.

FOR $c in (world_temp) LET $tmpCov := coverage x domain crs "EPSG:4326" with lat regular (-90:90) resolution -10, lon regular (-180:180) resolution 10 range type red quantity unsigned char, green quantity unsigned char, blue quantity unsigned char range set decode($1) RETURN encode( $tmpCov * log($c) , "image/png")

Example 3 - The expression below creates a 1-D temporal coverage; for each timeslice it contains the summary of values (calculated by general condenser) from the original coverage $c corresponding to that timeslice

Example 4 - The expression below applies a 3x3 matrix (created as a coverage constant) as a Sobel filter on a 2-D grid-indexed coverage.

FOR c in (NIR) LET $k := coverage Sobel3x3 over $px i ( -1 : +1 ), $py j ( -1 : +1 ) values < 1; 2; 1; 0; 0; 0; -1; -2; -1 > RETURN encode( coverage FilteredImage domain crs "OGC:Index2D" with x index (50 : 600), y index (250 : 650) range type grey quantity int range set condense + over $pi i(-1 : 1), $pj j(-1 : 1) using c[i(x + $pi), j(y + $pj)].red * $k[i($pi), j($pj)] , "image/png")