get wms result as image

geoengine/types.py

@@ -60,16 +60,24 @@ def bbox_str(self) -> str:
         return ','.join(map(str, self.__spatial_bounds))
 
     @property
-    def bbox_ogc(self) -> str:
+    def bbox_ogc_str(self) -> str:
         '''
-        TODO: what is this method and why does it say that is returns a string?
+        A comma-separated string representation of the spatial bounds with OGC axis ordering
+        '''
+
+        return ','.join(map(str, self.bbox_ogc))
+
+    @property
+    def bbox_ogc(self) -> Tuple[float, float, float, float]:
+        '''
+        Return the bbox with OGC axis ordering of the srs
         '''
 
         # TODO: properly handle axis order
         bbox = self.__spatial_bounds
 
         if self.__srs == "EPSG:4326":
-            return [bbox[1], bbox[0], bbox[3], bbox[2]]
+            return (bbox[1], bbox[0], bbox[3], bbox[2])
 
         return bbox
 

geoengine/workflow.py

@@ -3,11 +3,11 @@
 '''
 
 from __future__ import annotations
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Tuple
 
 from uuid import UUID
 from logging import debug
-from io import StringIO
+from io import StringIO, BytesIO
 import urllib.parse
 import json
 
@@ -20,6 +20,7 @@
 import rasterio
 from vega import VegaLite
 import numpy as np
+from PIL import Image
 
 from geoengine.types import ProvenanceOutput, QueryRectangle, ResultDescriptor
 from geoengine.auth import get_session
@@ -205,7 +206,7 @@ def srs_to_projection(srs: str) -> ccrs.Projection:
 
             [authority, code] = srs.split(':')
 
-            if authority != 'EPSG:':
+            if authority != 'EPSG':
                 return fallback
             try:
                 return ccrs.epsg(code)
@@ -236,7 +237,17 @@ def srs_to_projection(srs: str) -> ccrs.Projection:
 
         return ax
 
-    def wms_get_map_curl(self, bbox: QueryRectangle) -> str:
+    def wms_get_map_as_image(self, bbox: QueryRectangle, colorizer_min_max: Tuple[float, float] = None) -> Image:
+        '''Return the result of a WMS request as a PIL Image'''
+
+        wms_request = self.__wms_get_map_request(bbox, colorizer_min_max)
+        response = req.Session().send(wms_request)
+
+        return Image.open(BytesIO(response.content))
+
+    def __wms_get_map_request(self,
+                              bbox: QueryRectangle,
+                              colorizer_min_max: Tuple[float, float] = None) -> req.PreparedRequest:
         '''Return the WMS url for a workflow and a given `QueryRectangle`'''
 
         if not self.__result_descriptor.is_raster_result():
@@ -247,27 +258,47 @@ def wms_get_map_curl(self, bbox: QueryRectangle) -> str:
         width = int((bbox.xmax - bbox.xmin) / bbox.resolution[0])
         height = int((bbox.ymax - bbox.ymin) / bbox.resolution[1])
 
+        colorizer = ''
+        if colorizer_min_max is not None:
+            colorizer = 'custom:' + json.dumps({
+                "type": "linearGradient",
+                "breakpoints": [{
+                    "value": colorizer_min_max[0],
+                    "color": [0, 0, 0, 255]
+                }, {
+                    "value": colorizer_min_max[1],
+                    "color": [255, 255, 255, 255]
+                }],
+                "noDataColor": [0, 0, 0, 0],
+                "defaultColor": [0, 0, 0, 0]
+            })
+
         params = dict(
             service='WMS',
             version='1.3.0',
             request="GetMap",
             layers=str(self),
             time=bbox.time_str,
             crs=bbox.srs,
-            bbox=bbox.bbox_str,
+            bbox=bbox.bbox_ogc_str,
             width=width,
             height=height,
             format='image/png',
-            styles='',  # TODO: incorporate styling
+            styles=colorizer,  # TODO: incorporate styling properly
         )
 
-        wms_request = req.Request(
+        return req.Request(
             'GET',
             url=f'{session.server_url}/wms',
             params=params,
             headers=session.auth_header
         ).prepare()
 
+    def wms_get_map_curl(self, bbox: QueryRectangle, colorizer_min_max: Tuple[float, float] = None) -> str:
+        '''Return the WMS curl command for a workflow and a given `QueryRectangle`'''
+
+        wms_request = self.__wms_get_map_request(bbox, colorizer_min_max)
+
         command = "curl -X {method} -H {headers} '{uri}'"
         headers = ['"{0}: {1}"'.format(k, v) for k, v in wms_request.headers.items()]
         headers = " -H ".join(headers)

setup.cfg

@@ -18,16 +18,17 @@ package_dir =
 packages = find:
 python_requires = >=3.7
 install_requires =
-    numpy
     cartopy
     geopandas
     matplotlib
+    numpy
     owslib
+    pillow
     pyepsg # for cartopy
+    rasterio
     requests
     scipy # for cartopy
     vega
-    rasterio
 
 [options.packages.find]
 where = .

tests/responses/4326.gml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+ <gml:GeodeticCRS xmlns:epsg="urn:x-ogp:spec:schema-xsd:EPSG:1.0:dataset" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:xlink="http://www.w3.org/1999/xlink" gml:id="epsg-crs-4326">
+   <gml:metaDataProperty>
+      <epsg:CommonMetaData>
+         <epsg:type>geographic 2D</epsg:type>
+         <epsg:informationSource>EPSG. See 3D CRS for original information source.</epsg:informationSource>
+         <epsg:revisionDate>2007-08-27</epsg:revisionDate>
+         <epsg:changes>
+            <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2002.151" />
+            <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2003.370" />
+            <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2006.810" />
+            <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2007.079" />
+         </epsg:changes>
+         <epsg:show>true</epsg:show>
+         <epsg:isDeprecated>false</epsg:isDeprecated>
+      </epsg:CommonMetaData>
+   </gml:metaDataProperty>
+   <gml:metaDataProperty>
+      <epsg:CRSMetaData>
+         <epsg:projectionConversion xlink:href="urn:ogc:def:coordinateOperation:EPSG::15593" />
+         <epsg:sourceGeographicCRS xlink:href="urn:ogc:def:crs:EPSG::4979" />
+      </epsg:CRSMetaData>
+   </gml:metaDataProperty>
+   <gml:identifier codeSpace="OGP">urn:ogc:def:crs:EPSG::4326</gml:identifier>
+   <gml:name>WGS 84</gml:name>
+   <gml:domainOfValidity xlink:href="urn:ogc:def:area:EPSG::1262" />
+   <gml:scope>Horizontal component of 3D system. Used by the GPS satellite navigation system and for NATO military geodetic surveying.</gml:scope>
+   <gml:ellipsoidalCS xlink:href="urn:ogc:def:cs:EPSG::6422" />
+   <gml:geodeticDatum xlink:href="urn:ogc:def:datum:EPSG::6326" />
+</gml:GeodeticCRS>

tests/test_wms.py

@@ -3,6 +3,7 @@
 from datetime import datetime
 import unittest
 import textwrap
+from PIL import Image
 
 import requests_mock
 import cartopy.mpl.geoaxes
@@ -22,7 +23,7 @@ def setUp(self) -> None:
     @responses.activate
     @ImageTesting(['wms'], tolerance=0)
     def test_ndvi(self):
-        with requests_mock.Mocker() as m:
+        with requests_mock.Mocker() as m, open("tests/responses/4326.gml", "rb") as epsg4326_gml:
             m.post('http://mock-instance/anonymous', json={
                 "id": "c4983c3e-9b53-47ae-bda9-382223bd5081",
                 "project": None,
@@ -47,6 +48,8 @@ def test_ndvi(self):
                   },
                   request_headers={'Authorization': 'Bearer c4983c3e-9b53-47ae-bda9-382223bd5081'})
 
+            m.get('http://epsg.io/4326.gml?download', body=epsg4326_gml)
+
             # Unfortunately, we need a separate library to catch the request from the WMS call
             with open("tests/responses/wms-ndvi.png", "rb") as wms_ndvi:
                 responses.add(
@@ -90,16 +93,84 @@ def test_ndvi(self):
             self.assertEqual(type(ax), cartopy.mpl.geoaxes.GeoAxesSubplot)
 
             # Check requests from the mocker
-            self.assertEqual(len(m.request_history), 3)
+            self.assertEqual(len(m.request_history), 4)
 
             workflow_request = m.request_history[1]
             self.assertEqual(workflow_request.method, "POST")
             self.assertEqual(workflow_request.url,
                              "http://mock-instance/workflow")
             self.assertEqual(workflow_request.json(), workflow_definition)
 
+    def test_ndvi_image(self):
+        with requests_mock.Mocker() as m,\
+                open("tests/responses/wms-ndvi.png", "rb") as ndvi_png,\
+                open("tests/responses/4326.gml", "rb") as epsg4326_gml:
+            m.post('http://mock-instance/anonymous', json={
+                "id": "c4983c3e-9b53-47ae-bda9-382223bd5081",
+                "project": None,
+                "view": None
+            })
+
+            m.post('http://mock-instance/workflow',
+                   json={
+                       "id": "5b9508a8-bd34-5a1c-acd6-75bb832d2d38"
+                   },
+                   request_headers={'Authorization': 'Bearer c4983c3e-9b53-47ae-bda9-382223bd5081'})
+
+            m.get('http://mock-instance/workflow/5b9508a8-bd34-5a1c-acd6-75bb832d2d38/metadata',
+                  json={
+                      "type": "raster",
+                      "dataType": "U8",
+                      "spatialReference": "EPSG:4326",
+                      "measurement": {
+                              "type": "unitless"
+                      },
+                      "noDataValue": 0.0
+                  },
+                  request_headers={'Authorization': 'Bearer c4983c3e-9b53-47ae-bda9-382223bd5081'})
+
+            m.get('http://epsg.io/4326.gml?download', body=epsg4326_gml)
+
+            # Unfortunately, we need a separate library to catch the request from the WMS call
+            m.get(
+                # pylint: disable=line-too-long
+                'http://mock-instance/wms?service=WMS&version=1.3.0&request=GetMap&layers=5b9508a8-bd34-5a1c-acd6-75bb832d2d38&time=2014-04-01T12%3A00%3A00.000%2B00%3A00&crs=EPSG%3A4326&bbox=-90.0%2C-180.0%2C90.0%2C180.0&width=200&height=100&format=image%2Fpng&styles=custom%3A%7B%22type%22%3A+%22linearGradient%22%2C+%22breakpoints%22%3A+%5B%7B%22value%22%3A+0%2C+%22color%22%3A+%5B0%2C+0%2C+0%2C+255%5D%7D%2C+%7B%22value%22%3A+255%2C+%22color%22%3A+%5B255%2C+255%2C+255%2C+255%5D%7D%5D%2C+%22noDataColor%22%3A+%5B0%2C+0%2C+0%2C+0%5D%2C+%22defaultColor%22%3A+%5B0%2C+0%2C+0%2C+0%5D%7D',
+                body=ndvi_png,
+            )
+
+            ge.initialize("http://mock-instance")
+
+            workflow_definition = {
+                "type": "Raster",
+                "operator": {
+                    "type": "GdalSource",
+                    "params": {
+                        "dataset": {
+                            "type": "internal",
+                            "datasetId": "36574dc3-560a-4b09-9d22-d5945f2b8093"
+                        }
+                    }
+                }
+            }
+
+            time = datetime.strptime(
+                '2014-04-01T12:00:00.000Z', "%Y-%m-%dT%H:%M:%S.%f%z")
+
+            workflow = ge.register_workflow(workflow_definition)
+
+            img = workflow.wms_get_map_as_image(
+                QueryRectangle(
+                    [-180.0, -90.0, 180.0, 90.0],
+                    [time, time],
+                    resolution=(1.8, 1.8)
+                ),
+                colorizer_min_max=(0, 255)
+            )
+
+            self.assertEqual(img, Image.open("tests/responses/wms-ndvi.png"))
+
     def test_wms_url(self):
-        with requests_mock.Mocker() as m:
+        with requests_mock.Mocker() as m, open("tests/responses/4326.gml", "rb") as epsg4326_gml:
             m.post('http://mock-instance/anonymous', json={
                 "id": "c4983c3e-9b53-47ae-bda9-382223bd5081",
                 "project": None,
@@ -124,6 +195,8 @@ def test_wms_url(self):
                   },
                   request_headers={'Authorization': 'Bearer c4983c3e-9b53-47ae-bda9-382223bd5081'})
 
+            m.get('http://epsg.io/4326.gml?download', body=epsg4326_gml)
+
             ge.initialize("http://mock-instance")
 
             workflow_definition = {
@@ -153,7 +226,7 @@ def test_wms_url(self):
             self.assertEqual(
                 # pylint: disable=line-too-long
                 wms_curl,
-                """curl -X GET -H "Authorization: Bearer c4983c3e-9b53-47ae-bda9-382223bd5081" 'http://mock-instance/wms?service=WMS&version=1.3.0&request=GetMap&layers=5b9508a8-bd34-5a1c-acd6-75bb832d2d38&time=2014-04-01T12%3A00%3A00.000%2B00%3A00&crs=EPSG%3A4326&bbox=-180.0%2C-90.0%2C180.0%2C90.0&width=360&height=180&format=image%2Fpng&styles='"""
+                """curl -X GET -H "Authorization: Bearer c4983c3e-9b53-47ae-bda9-382223bd5081" 'http://mock-instance/wms?service=WMS&version=1.3.0&request=GetMap&layers=5b9508a8-bd34-5a1c-acd6-75bb832d2d38&time=2014-04-01T12%3A00%3A00.000%2B00%3A00&crs=EPSG%3A4326&bbox=-90.0%2C-180.0%2C90.0%2C180.0&width=360&height=180&format=image%2Fpng&styles='"""
             )
 
     def test_result_descriptor(self):