Add Raster getPixel and crop methods

Author: jericks

doc/api/raster.rst

@@ -97,6 +97,12 @@ Properties
 Methods
 -------
 
+.. function:: Raster.getPixel(point)
+
+    :arg point: :class:`geom.Point` The geographic Point
+
+    Get a pixel ``Object`` with x and y properies.
+
 .. function:: Raster.getPoint(x,y)
 
     :arg x: ``Number`` The pixel's x position
@@ -113,6 +119,11 @@ Methods
 
     Get a value for each band from the Raster.
 
+.. function:: Raster.crop(bounds)
+
+    :arg bounds: :class:`geom.Bound` The Bounds of the new Raster
+
+    Crop the current Raster to only include data in the given Bounds.
 
 :class:`raster.Band`
 ====================

src/main/java/org/geoscript/js/raster/Raster.java

@@ -8,15 +8,18 @@
 import org.geotools.coverage.grid.GridCoverage2D;
 import org.geotools.coverage.grid.GridEnvelope2D;
 import org.geotools.coverage.grid.GridGeometry2D;
+import org.geotools.coverage.processing.CoverageProcessor;
 import org.geotools.geometry.DirectPosition2D;
 import org.geotools.geometry.jts.ReferencedEnvelope;
 import org.mozilla.javascript.*;
 import org.mozilla.javascript.annotations.JSConstructor;
 import org.mozilla.javascript.annotations.JSFunction;
 import org.mozilla.javascript.annotations.JSGetter;
+import org.opengis.coverage.Coverage;
 import org.opengis.coverage.SampleDimension;
 import org.opengis.geometry.DirectPosition;
 import org.opengis.geometry.Envelope;
+import org.opengis.parameter.ParameterValueGroup;
 import org.opengis.referencing.crs.CoordinateReferenceSystem;
 import org.opengis.referencing.operation.TransformException;
 
@@ -106,6 +109,20 @@ public Point getPoint(int x, int y) {
         }
     }
 
+    @JSFunction
+    public NativeObject getPixel(Point point) {
+        GridGeometry2D gg = coverage.getGridGeometry();
+        try {
+            GridCoordinates2D gridCoordinates2D = gg.worldToGrid(new DirectPosition2D((double) point.getX(), (double) point.getY()));
+            Map<String, Double> pixel = new HashMap<>();
+            pixel.put("x", gridCoordinates2D.getX());
+            pixel.put("y", gridCoordinates2D.getY());
+            return (NativeObject) javaToJS(pixel, this.getParentScope());
+        } catch (TransformException e) {
+            throw ScriptRuntime.constructError("Error", "Error getting Pixel coordinate from Point for Raster.");
+        }
+    }
+
     @JSFunction
     public Object getValue(Object pointOrPixel) {
         Point point;
@@ -122,6 +139,16 @@ public Object getValue(Object pointOrPixel) {
         return javaToJS(result, getParentScope());
     }
 
+    @JSFunction
+    public Raster crop(Bounds bounds) {
+        CoverageProcessor processor = new CoverageProcessor();
+        ParameterValueGroup params = processor.getOperation("CoverageCrop").getParameters();
+        params.parameter("Source").setValue(coverage);
+        params.parameter("Envelope").setValue(new org.geotools.geometry.GeneralEnvelope(bounds.unwrap()));
+        GridCoverage2D newCoverage = (GridCoverage2D) processor.doOperation(params);
+        return new Raster(this.getParentScope(), newCoverage);
+    }
+
     @Override
     public String toString() {
         return this.getName();

src/test/resources/org/geoscript/js/tests/geoscript/raster/test_raster.js

@@ -75,7 +75,25 @@ exports["test: get raster point from pixel"] = function() {
 exports["test: get raster point from pixel"] = function() {
     var format = new raster.Format({source: admin.raster.source});
     var tif = format.read({});
-    print(tif.getValue(new geom.Point([-175.8, 81.8])));
-    //assert.strictEqual(-69, tif.getValue(new geom.Point([-175.8, 81.8]), "double")[0], "Value should be -69");
-    //assert.strictEqual(-69, tif.getValue({x: 10, y: 20}, "double")[0], "Value should be -69");
+    assert.strictEqual(-69, tif.getValue(new geom.Point([-175.8, 81.8]), "double")[0], "Value should be -69");
+    assert.strictEqual(-69, tif.getValue({x: 10, y: 20}, "double")[0], "Value should be -69");
+};
+
+exports["test: get raster pixel from point"] = function() {
+    var format = new raster.Format({source: admin.raster.source});
+    var tif = format.read({});
+    var pixel = tif.getPixel(new geom.Point([-175.8, 81.8]));
+    assert.strictEqual(10, pixel.x, "Value should be 10");
+    assert.strictEqual(20, pixel.y, "Value should be 20");
+};
+
+exports["test: crop a raster"] = function() {
+    var format = new raster.Format({source: admin.raster.source});
+    var tif = format.read({});
+    var smallTif = tif.crop(new geom.Bounds([-180,-90, 0, 0]))
+    var bounds = smallTif.bounds;
+    assert.strictEqual(-180, Math.round(bounds.minX), "Min X should be -180");
+    assert.strictEqual(-90,  Math.round(bounds.minY), "Min Y should be -90");
+    assert.strictEqual(0,    Math.round(bounds.maxX), "Max X should be 0");
+    assert.strictEqual(0,    Math.round(bounds.maxY), "Max Y should be 0");
 };