add validation of MLM output using classification:classes (fixes #48) (…

…#50)

CHANGELOG.md

@@ -9,6 +9,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Validation by the JSON schema of `classification:classes` definition within a
+  [Machine Learning Model (MLM)](https://github.com/crim-ca/mlm-extension) output.
+- Example STAC `item-model-classes.json` demonstrating the use of `classification:classes` within a `mlm:output`.
+- `nodata` to `classification:classes`
 - `nodata` to Class Object
 - `percentage` to Class Object
 - `count` to Class Object

README.md

@@ -12,8 +12,10 @@ This document explains the Classification Extension to the
 
 - Examples:
   - Asset level:
-    - [Classes example](examples/item-classes-maxar.json): STAC Item with classified raster bands in asset (Maxar)
+    - [Raster Classes example](examples/item-classes-maxar.json): STAC Item with classified raster bands in asset (Maxar)
     - [Bitfields example](examples/item-bitfields-landsat.json): STAC Item with bit fields in asset (Landsat)
+  - Item level:
+    - [Model Classes example](examples/item-model-classes.json): STAC Item with classes of a Machine Learning Model output
   - Collection level:
     - [Item Assets example](examples/collection-item-assets.json): STAC Collection using Item Assets for classed child Items
 - [JSON Schema](json-schema/schema.json)
@@ -41,9 +43,11 @@ position of the first bit in a field is given by its offset. Therefore the first
 
 These classification objects can be used in the following places:
 
-- In a raster Asset object if single band.
+- In a [raster Asset object](https://github.com/stac-extensions/raster#item-asset-fields) if single band.
 - For multiband rasters, use [`raster:bands`](https://github.com/stac-extensions/raster) and store the classes in
   each Band Object.
+- In a [Machine Learning Model output object](https://github.com/crim-ca/mlm-extension#model-output-object) to
+  define the classes represented within that output.
 - As an [`item-assets`](https://github.com/stac-extensions/item-assets) field in a Collection object, to indicate
   that the classification is used across child Items.