Merge pull request #5090 from nyalldawson/raster_layer_extent

[FEATURE] New algorithm for creating vector layer from raster layer's extent
qgis · Aug 30, 2017 · 9fa12ac · 9fa12ac
2 parents 6fe6394 + bb5a499
commit 9fa12ac
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Showing 8 changed files with 246 additions and 7 deletions.
diff --git a/python/plugins/processing/algs/help/qgis.yaml b/python/plugins/processing/algs/help/qgis.yaml
@@ -402,12 +402,14 @@ qgis:polygoncentroids: >
 
   NOTE: This algorithm is deprecated and the generic "centroids" algorithm (which works for line and multi geometry layers) should be used instead.
 
-
 qgis:polygonfromlayerextent: >
   This algorithm takes a vector layer and generates a new one with the minimum bounding box (rectangle with N-S orientation) that covers all the input features.
 
   As an alternative, the output layer can contain not just a single bounding box, but one for each input feature, representing the bounding box of each of them.
 
+qgis:polygonfromrasterextent: >
+  This algorithm takes a raster layer and generates a vector layer containing a feature with the minimum bounding box that covers the raster layer's extent.
+
 qgis:polygonize:  >
   This algorithm takes a lines layer and creates a polygon layer, with polygons generated from the lines in the input layer.
 

diff --git a/python/plugins/processing/algs/qgis/ExtentFromLayer.py b/python/plugins/processing/algs/qgis/ExtentFromLayer.py
@@ -49,7 +49,7 @@
 
 class ExtentFromLayer(QgisAlgorithm):
 
-    INPUT_LAYER = 'INPUT_LAYER'
+    INPUT = 'INPUT'
     BY_FEATURE = 'BY_FEATURE'
 
     OUTPUT = 'OUTPUT'
@@ -67,7 +67,7 @@ def __init__(self):
         super().__init__()
 
     def initAlgorithm(self, config=None):
-        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT_LAYER, self.tr('Input layer')))
+        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT, self.tr('Input layer')))
         self.addParameter(QgsProcessingParameterBoolean(self.BY_FEATURE,
                                                         self.tr('Calculate extent for each feature separately'), False))
 
@@ -77,10 +77,10 @@ def name(self):
         return 'polygonfromlayerextent'
 
     def displayName(self):
-        return self.tr('Polygon from layer extent')
+        return self.tr('Polygon from vector extent')
 
     def processAlgorithm(self, parameters, context, feedback):
-        source = self.parameterAsSource(parameters, self.INPUT_LAYER, context)
+        source = self.parameterAsSource(parameters, self.INPUT, context)
         byFeature = self.parameterAsBool(parameters, self.BY_FEATURE, context)
 
         fields = QgsFields()

diff --git a/python/plugins/processing/algs/qgis/ExtentFromRasterLayer.py b/python/plugins/processing/algs/qgis/ExtentFromRasterLayer.py
@@ -0,0 +1,127 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    ExtentFromRasterLayer.py
+    ---------------------
+    Date                 : August 2017
+    Copyright            : (C) 2017 by Nyall Dawson
+    Email                : nyall dot dawson at gmail dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+__author__ = 'Nyall Dawson'
+__date__ = 'August 2017'
+__copyright__ = '(C) 2017, Nyall Dawson'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+import os
+
+from qgis.PyQt.QtGui import QIcon
+from qgis.PyQt.QtCore import QVariant
+
+from qgis.core import (QgsField,
+                       QgsFeatureSink,
+                       QgsPointXY,
+                       QgsGeometry,
+                       QgsFeature,
+                       QgsWkbTypes,
+                       QgsProcessing,
+                       QgsProcessingParameterRasterLayer,
+                       QgsProcessingParameterFeatureSink,
+                       QgsFields)
+
+from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
+
+pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
+
+
+class ExtentFromRasterLayer(QgisAlgorithm):
+
+    INPUT = 'INPUT'
+    OUTPUT = 'OUTPUT'
+
+    def icon(self):
+        return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'layer_extent.png'))
+
+    def tags(self):
+        return self.tr('extent,envelope,bounds,bounding,boundary,layer').split(',')
+
+    def group(self):
+        return self.tr('Raster tools')
+
+    def __init__(self):
+        super().__init__()
+
+    def initAlgorithm(self, config=None):
+        self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT, self.tr('Input layer')))
+        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Extent'), type=QgsProcessing.TypeVectorPolygon))
+
+    def name(self):
+        return 'polygonfromrasterextent'
+
+    def displayName(self):
+        return self.tr('Polygon from raster extent')
+
+    def processAlgorithm(self, parameters, context, feedback):
+        raster = self.parameterAsRasterLayer(parameters, self.INPUT, context)
+
+        fields = QgsFields()
+        fields.append(QgsField('MINX', QVariant.Double))
+        fields.append(QgsField('MINY', QVariant.Double))
+        fields.append(QgsField('MAXX', QVariant.Double))
+        fields.append(QgsField('MAXY', QVariant.Double))
+        fields.append(QgsField('CNTX', QVariant.Double))
+        fields.append(QgsField('CNTY', QVariant.Double))
+        fields.append(QgsField('AREA', QVariant.Double))
+        fields.append(QgsField('PERIM', QVariant.Double))
+        fields.append(QgsField('HEIGHT', QVariant.Double))
+        fields.append(QgsField('WIDTH', QVariant.Double))
+
+        (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
+                                               fields, QgsWkbTypes.Polygon, raster.crs())
+
+        self.layerExtent(raster, sink, feedback)
+
+        return {self.OUTPUT: dest_id}
+
+    def layerExtent(self, raster, sink, feedback):
+        rect = raster.extent()
+        geometry = QgsGeometry.fromRect(rect)
+        minx = rect.xMinimum()
+        miny = rect.yMinimum()
+        maxx = rect.xMaximum()
+        maxy = rect.yMaximum()
+        height = rect.height()
+        width = rect.width()
+        cntx = minx + width / 2.0
+        cnty = miny + height / 2.0
+        area = width * height
+        perim = 2 * width + 2 * height
+
+        feat = QgsFeature()
+        feat.setGeometry(geometry)
+        attrs = [
+            minx,
+            miny,
+            maxx,
+            maxy,
+            cntx,
+            cnty,
+            area,
+            perim,
+            height,
+            width,
+        ]
+        feat.setAttributes(attrs)
+        sink.addFeature(feat, QgsFeatureSink.FastInsert)
diff --git a/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py b/python/plugins/processing/algs/qgis/QGISAlgorithmProvider.py
@@ -70,6 +70,7 @@
 from .ExportGeometryInfo import ExportGeometryInfo
 from .ExtendLines import ExtendLines
 from .ExtentFromLayer import ExtentFromLayer
+from .ExtentFromRasterLayer import ExtentFromRasterLayer
 from .ExtractNodes import ExtractNodes
 from .ExtractSpecificNodes import ExtractSpecificNodes
 from .FieldPyculator import FieldsPyculator
@@ -222,6 +223,7 @@ def getAlgs(self):
                 ExportGeometryInfo(),
                 ExtendLines(),
                 ExtentFromLayer(),
+                ExtentFromRasterLayer(),
                 ExtractNodes(),
                 ExtractSpecificNodes(),
                 FieldsCalculator(),

diff --git a/python/plugins/processing/gui/TestTools.py b/python/plugins/processing/gui/TestTools.py
@@ -27,6 +27,7 @@
 __revision__ = '$Format:%H$'
 
 import os
+import posixpath
 import re
 import yaml
 import hashlib
@@ -81,7 +82,8 @@ def extractSchemaPath(filepath):
         if part == 'testdata' and not localpath:
             localparts = parts
             localparts.reverse()
-            localpath = os.path.join(*localparts)
+            # we always want posix style paths here
+            localpath = posixpath.join(*localparts)
 
         parts.append(part)
 

diff --git a/python/plugins/processing/tests/testdata/expected/raster_extent.gfs b/python/plugins/processing/tests/testdata/expected/raster_extent.gfs
@@ -0,0 +1,66 @@
+<GMLFeatureClassList>
+  <GMLFeatureClass>
+    <Name>raster_extent</Name>
+    <ElementPath>raster_extent</ElementPath>
+    <!--POLYGON-->
+    <GeometryType>3</GeometryType>
+    <SRSName>EPSG:4326</SRSName>
+    <DatasetSpecificInfo>
+      <FeatureCount>1</FeatureCount>
+      <ExtentXMin>18.66630</ExtentXMin>
+      <ExtentXMax>18.70360</ExtentXMax>
+      <ExtentYMin>45.77670</ExtentYMin>
+      <ExtentYMax>45.81170</ExtentYMax>
+    </DatasetSpecificInfo>
+    <PropertyDefn>
+      <Name>MINX</Name>
+      <ElementPath>MINX</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>MINY</Name>
+      <ElementPath>MINY</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>MAXX</Name>
+      <ElementPath>MAXX</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>MAXY</Name>
+      <ElementPath>MAXY</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>CNTX</Name>
+      <ElementPath>CNTX</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>CNTY</Name>
+      <ElementPath>CNTY</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>AREA</Name>
+      <ElementPath>AREA</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>PERIM</Name>
+      <ElementPath>PERIM</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>HEIGHT</Name>
+      <ElementPath>HEIGHT</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+    <PropertyDefn>
+      <Name>WIDTH</Name>
+      <ElementPath>WIDTH</ElementPath>
+      <Type>Real</Type>
+    </PropertyDefn>
+  </GMLFeatureClass>
+</GMLFeatureClassList>
diff --git a/python/plugins/processing/tests/testdata/expected/raster_extent.gml b/python/plugins/processing/tests/testdata/expected/raster_extent.gml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ogr:FeatureCollection
+     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+     xsi:schemaLocation=""
+     xmlns:ogr="http://ogr.maptools.org/"
+     xmlns:gml="http://www.opengis.net/gml">
+  <gml:boundedBy>
+    <gml:Box>
+      <gml:coord><gml:X>18.6662979442</gml:X><gml:Y>45.7767014376</gml:Y></gml:coord>
+      <gml:coord><gml:X>18.7035979442</gml:X><gml:Y>45.8117014376</gml:Y></gml:coord>
+    </gml:Box>
+  </gml:boundedBy>
+
+  <gml:featureMember>
+    <ogr:raster_extent fid="raster_extent.0">
+      <ogr:geometryProperty><gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>18.6662979442,45.7767014376 18.7035979442,45.7767014376 18.7035979442,45.8117014376 18.6662979442,45.8117014376 18.6662979442,45.7767014376</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon></ogr:geometryProperty>
+      <ogr:MINX>18.6662979442</ogr:MINX>
+      <ogr:MINY>45.7767014376</ogr:MINY>
+      <ogr:MAXX>18.7035979442</ogr:MAXX>
+      <ogr:MAXY>45.8117014376</ogr:MAXY>
+      <ogr:CNTX>18.6849479442</ogr:CNTX>
+      <ogr:CNTY>45.7942014376</ogr:CNTY>
+      <ogr:AREA>0.00130549999999981</ogr:AREA>
+      <ogr:PERIM>0.14459999999999</ogr:PERIM>
+      <ogr:HEIGHT>0.0349999999999966</ogr:HEIGHT>
+      <ogr:WIDTH>0.0372999999999983</ogr:WIDTH>
+    </ogr:raster_extent>
+  </gml:featureMember>
+</ogr:FeatureCollection>
diff --git a/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml b/python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml
@@ -2845,7 +2845,7 @@ tests:
     name: Standard polygon from layer extent
     params:
       BY_FEATURE: false
-      INPUT_LAYER:
+      INPUT:
         name: polys.gml
         type: vector
     results:
@@ -3228,3 +3228,14 @@ tests:
       OUTPUT:
         name: expected/execute_sql.gml
         type: vector
+
+  - algorithm: qgis:polygonfromrasterextent
+    name: Polygon from raster extent
+    params:
+      INPUT:
+        name: dem.tif
+        type: raster
+    results:
+      OUTPUT:
+        name: expected/raster_extent.gml
+        type: vector