== WCS Best Practices for Interoperability

This page is created for gathering best practices about how to use WCS so that it 
1) is standard compliant
2) helps with achieving interoperability between different implementations.


Related mailing list threads:

https://lists.osgeo.org/pipermail/gdal-dev/2017-April/046366.html

https://lists.osgeo.org/pipermail/gdal-dev/2017-November/047650.html 



== Test data

Sample image A from the WCS KISS dataset

[[Image(WCS_KISS_Image_A.png)]]



Sample image B from the WCS KISS dataset

[[Image(WCS_KISS_Image_B.png)]]



Image A is an exact SUBSET of image B



Images are of type "pixel is area". The pixel centers show in this image


[[Image(WCS_KISS_Image_A_with_pixel_centers.png)]]


== Extents of the test images

1) In first case the raster images are somewhere in Chine where the longitude is greater than 90. Polygons which contain completely all the pixels are in the PostGIS EWKT format:

Image A:
SRID:4326;POLYGON (( 115 30, 115 33, 117 33, 117 30, 115 30 ))

Image B:
SRID:4326;POLYGON (( 114 29, 114 34, 118 34, 118 29, 114 29 ))


Image A has width=2 and height=3 and it can be constructed from an array:
[Red,Red,Green,Green,Blue,Blue]

Image B has width=4 and height=5 and can be constructed from an array:
[Grey,Grey,Grey,Grey,Grey,Red,Red,Grey,Grey,Green,Green,Grey,Grey,Blue,Blue,Grey,Grey,Grey,Grey,Grey]

A.tfw

1

0

0

-1

115.5

32.5

B.tfw

1

0

0

-1

114.5

33.5