Clarify Tile-variables, add WMTS REST example

Author: m-mohr

README.md

@@ -115,7 +115,12 @@ This describes the REST request encoding, which provides a URL template with var
 | uriTemplate   | string           | Can override the URL template from the capabilities document with a custom version that can be customized with the `variables` provided. |
 | variables     | Map\<string, \*> | This object contains one key per substitution variable in the `urlTemplate`. |
 
-**variables**: This object may provide a JSON Schema definition for any variable defined in the `uriTemplate`, allowing to provide the default value for the specific STAC resource or the specification of ranges or other constraints.
+**variables**: This object may provide a JSON Schema definition for any variable defined in the `uriTemplate`,
+allowing to provide the default value for the specific STAC resource or the specification of ranges or other constraints.
+
+The variables `{TileMatrixSet}`, `{TileMatrix}`, `{TileRow}`, `{TileCol}` do not need to be provided
+explicitly in the `variables` as they can be determined from the capabilities.
+Nevertheless, the corresponding variables can be provided if they should be further restricted to certain values or other contraints.
 
 Providing a reasonable default value for all variables is strongly recommended as they
 are likely to be used for a default visualization.

examples/collection.json

@@ -42,10 +42,35 @@
       "href": "https://maps.example.com/wmts",
       "rel": "wmts",
       "type": "image/png",
-      "title": "RGB composite visualized through a WMTS",
-      "wmts:layer": "rgb",
+      "title": "Mosaic visualized through a WMTS (KVP)",
+      "wmts:layer": "mosaic",
       "wmts:dimensions": {
-        "time": "2022-01-01"
+        "time": 2025
+      }
+    },
+    {
+      "href": "https://maps.example.com/wmts/WMTSCapabilities.xml",
+      "rel": "wmts",
+      "type": "application/xml",
+      "title": "Mosaic visualized through a WMTS (REST)",
+      "wmts:encoding": "rest",
+      "wmts:layer": "mosaic",
+      "uriTemplate": "https://maps.example.com/wmts/rest/mosaic/{time}/{style}/{TileMatrixSet}/{TileMatrix}/{TileRow}/{TileCol}.png",
+      "variables": {
+        "style": {
+          "type": "string",
+          "enum": [
+            "rgb",
+            "grayscale"
+          ],
+          "default": "rgb"
+        },
+        "time": {
+          "type": "integer",
+          "minimum": 2015,
+          "maximum": 2026,
+          "default": 2025
+        }
       }
     },
     {

examples/item.json

@@ -57,6 +57,35 @@
         "satellite"
       ]
     },
+    {
+      "href": "https://maps.example.com/wmts",
+      "rel": "wmts",
+      "type": "image/png",
+      "title": "Mosaic visualized through a WMTS (KVP)",
+      "wmts:layer": "mosaic",
+      "wmts:dimensions": {
+        "time": 2025
+      }
+    },
+    {
+      "href": "https://maps.example.com/wmts/WMTSCapabilities.xml",
+      "rel": "wmts",
+      "type": "application/xml",
+      "title": "Mosaic visualized through a WMTS (REST)",
+      "wmts:encoding": "rest",
+      "wmts:layer": "mosaic",
+      "uriTemplate": "https://maps.example.com/wmts/rest/mosaic/2025/{style}/{TileMatrixSet}/{TileMatrix}/{TileRow}/{TileCol}.png",
+      "variables": {
+        "style": {
+          "type": "string",
+          "enum": [
+            "rgb",
+            "grayscale"
+          ],
+          "default": "rgb"
+        }
+      }
+    },
     {
       "href": "https://maps.example.com/wms",
       "rel": "wms",