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Apply a raster function to a local raster file and display the output with a raster layer.
Use case
Raster functions allow processing operations that can be applied to one or more rasters on the fly. A land survey agency may apply hillshade and aspect functions to rasters with elevation data in order to better determine the topography of a landscape and to make further planning decisions.
How to use the sample
Load the sample to see a raster function applied to a raster.
How it works
Create a RasterFunction
using the path to a local raster function JSON file.
Set the raster function arguments as required by the function used.
Use the raster function to create a new Raster
.
Set the raster to a RasterLayer
and display it in the Map
.
Relevant API
Raster
RasterFunction
RasterLayer
Offline data
About the data
The raster function in the provided JSON file blends a color image with a greyscale image (in this case, a raster image containing elevation data), to add a hillshade effect to the input raster.
Learn more about raster functions in the ArcGIS Pro documentation.
analysis, function, image, layer, processing, raster, raster function, transformation
Sample CodeRasterFunctionFile.qml
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// [WriteFile Name=RasterFunctionFile, Category=Layers]
// [Legal]
// Copyright 2017 Esri.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// [Legal]
import QtQuick
import Esri.ArcGISRuntime
import Esri.ArcGISExtras
Rectangle {
id: rootRectangle
clip : true
width : 800
height : 600
property real scaleFactor : 1
readonly property url dataPath : {
Qt.platform.os === "ios" ?
System.writableLocationUrl(System.StandardPathsDocumentsLocation) + "/ArcGIS/Runtime/Data/raster" :
System.writableLocationUrl(System.StandardPathsHomeLocation) + "/ArcGIS/Runtime/Data/raster"
}
property url rasterPath : dataPath + "/Shasta_Elevation.tif"
MapView {
id: mapView
anchors.fill : parent
Component.onCompleted : {
// Set the focus on MapView to initially enable keyboard navigation
forceActiveFocus();
}
Map {
Basemap {
initStyle : Enums.BasemapStyleArcGISImageryStandard
}
RasterLayer {
id: rasterLayer
opacity : 0.5
Raster {
id: theRaster
path : rasterPath
}
}
ViewpointExtent {
Envelope {
json : {
"spatialReference" : {
"latestWkid" : 3857 ,
"wkid" : 102100
},
"xmax" : -13591503.517810356 ,
"xmin" : -13606233.44023646 ,
"ymax" : 4982810.138527592 ,
"ymin" : 4971762.696708013
}
}
}
}
}
// Create a button to apply the raster function
Rectangle {
id: button
enabled : theRaster.loadStatus === Enums.LoadStatusLoaded
property bool pressed : false
anchors {
right : parent .right
bottom : parent .bottom
rightMargin : 20 * scaleFactor
bottomMargin : 40 * scaleFactor
}
width : 45 * scaleFactor
height : width
color : pressed ? "#959595" : "#D6D6D6"
radius : 100
border {
color : "#585858"
width : 1 * scaleFactor
}
Image {
anchors {
centerIn : parent
verticalCenterOffset : -3 * scaleFactor
}
width : 26 * scaleFactor
height : width
source : "qrc:/Samples/Layers/RasterFunctionFile/color.png"
}
MouseArea {
anchors.fill : parent
onPressed : button.pressed = true
onReleased : button.pressed = false
onClicked : applyRasterFunction()
}
}
//! [RasterFunctionFile qml raster from function]
function applyRasterFunction ( ) {
// create raster function
const rasterFunction = createRasterFunction();
// check for valid raster function
if (!rasterFunction)
return ;
// create the raster from the raster function
const raster = ArcGISRuntimeEnvironment.createObject( "Raster" , { rasterFunction : rasterFunction });
// create raster layer from raster
const newRasterLayer = ArcGISRuntimeEnvironment.createObject( "RasterLayer" , { raster : raster });
newRasterLayer.opacity = 0.5 ;
// add raster to map
mapView.map.operationalLayers.clear();
mapView.map.operationalLayers.append(newRasterLayer);
}
function createRasterFunction ( ) {
// Check if the raster function json exists
if (!colorJson.exists)
return ;
// create the raster function
const rasterFunction = ArcGISRuntimeEnvironment.createObject( "RasterFunction" , { path : dataPath + "/color.json" });
// check for valid raster function
if (!rasterFunction)
return ;
rasterFunction.arguments.setRaster( "raster" , theRaster);
rasterFunction.arguments.setRaster( "raster" , theRaster);
return rasterFunction;
}
FileInfo {
id: colorJson
url : dataPath + "/color.json"
}
//! [RasterFunctionFile qml raster from function]
}