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ArcGIS Runtime SDK for Qt

Animate images with image overlay

Sample Viewer View Sample on GitHub

Animate a series of images with an image overlay.

Use case

An image overlay is useful for displaying fast and dynamic images; for example, rendering real-time sensor data captured from a drone. Each frame from the drone becomes a static image which is updated on the fly as the data is made available.

How to use the sample

The application loads a map of the Southwestern United States. Click the "Start" or "Stop" buttons to start or stop the radar animation. Use the drop down menu to select how quickly the animation plays. Move the slider to change the opacity of the image overlay.

How it works

  1. Create an ImageOverlay and add it to the SceneView.
  2. Set up a timer with an initial interval time of 68ms, which will display approximately 15 ImageFrames per second.
  3. Connect to the timeout signal from the timer.
  4. Create a new image frame every timeout and set it on the image overlay.

Relevant API

  • ImageFrame
  • ImageOverlay
  • SceneView

Offline data

Link Local Location
Pacific South West Images <userhome>/ArcGIS/Runtime/Data/3D/ImageOverlay/PacificSouthWest.zip

About the data

These radar images were captured by the US National Weather Service (NWS). They highlight the Pacific Southwest sector which is made up of part the western United States and Mexico. For more information visit the National Weather Service website.

Additional information

The supported image formats are GeoTIFF, TIFF, JPEG, and PNG. ImageOverlay does not support the rich processing and rendering capabilities of a RasterLayer. Use Raster and RasterLayer for static image rendering, analysis, and persistence.

Tags

3d, animation, drone, dynamic, image frame, image overlay, real time, rendering

Sample Code

import QtQuick 2.6
import QtQuick.Layouts 1.12
import QtQuick.Controls 2.12
import Esri.ArcGISRuntime 100.9
import Esri.ArcGISExtras 1.1

Rectangle {
    id: rootRectangle
    clip: true
    width: 800
    height: 600

    readonly property var timerIntervals: [17,34,68]
    readonly property var imageFrameRefreshRate: ["Fast","Medium","Slow"]
    readonly property url dataPath: System.userHomePath +  "/ArcGIS/Runtime/Data/3D/ImageOverlay/PacificSouthWest"
    property int fileNamesLength: 0

    // Create new Timer and set the timeout interval to 68ms
    Timer {
        id: timer
        interval: 68
        repeat: true
        property var index: 0

        // connect to the triggered signal to load and display a new image frame each time
        onTriggered: {
            // check if images are found before trying to load them
            if (fileNamesLength === 0)
                return;

            // create an image frame with the url to the image file and a extent
            let imageFrame = ArcGISRuntimeEnvironment.createObject("ImageFrame", {
                                                                       url: dataPath + "/" + imageFrameFolder.fileNames()[index],
                                                                       extent: imageFrameExtent
                                                                   });

            // set image frame to image overlay
            imageOverlay.imageFrame = imageFrame;

            // increment the index to keep track of which image to load next
            index++;

            // reset index once all files have been loaded
            if (index === fileNamesLength) {
                index = 0;
            }
        }
    }

    SceneView {
        id: sceneView
        anchors.fill: parent

        Scene {
            id: scene

            Surface {
                // create a new elevation source from Terrain3D REST service
                ArcGISTiledElevationSource {
                    url: "http://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"
                }
            }

            // create a new tiled layer from World_Dark_Gray_Base REST service
            ArcGISTiledLayer {
                id: worldDarkGrayBasemap
                url: "https://services.arcgisonline.com/arcgis/rest/services/Canvas/World_Dark_Gray_Base/MapServer"
            }

            // set an initial viewpoint
            ViewpointExtent {
                Point {
                    id: initialViewpoint
                    x: -116.621
                    y: 24.7773
                    z: 856977
                    spatialReference: SpatialReference { wkid: 4326 }
                }

                // create a camera, looking at the pacific southwest sector
                Camera {
                    id: camera
                    location: initialViewpoint
                    heading: 353.994
                    pitch: 48.5495
                    roll: 0
                }
            }
        }

        ImageOverlay {
            id: imageOverlay
        }

        Rectangle {
            id: controlsRect
            anchors {
                bottom: sceneView.attributionTop
                horizontalCenter: parent.horizontalCenter
            }
            width: childrenRect.width
            height: childrenRect.height
            color: "lightgrey"
            opacity: 0.8
            radius: 5
            ColumnLayout {
                id: controlsLayout
                Layout.alignment: Qt.AlignBottom
                spacing: 0

                Slider {
                    id: opacitySlider
                    from: 0
                    to: 1
                    value: 1
                    Layout.preferredHeight: bottomRowControls.height
                    Layout.alignment: Qt.AlignHCenter

                    onMoved: imageOverlay.opacity = value;

                    // Custom slider handle that displays the current value
                    handle: Item {
                        x: parent.leftPadding + parent.visualPosition * (parent.availableWidth - headingHandleNub.width)
                        y: parent.topPadding + parent.availableHeight / 2 - headingHandleNub.height / 2

                        Rectangle {
                            id: headingHandleNub
                            color: headingHandleRect.color
                            radius: width * 0.5
                            width: 20
                            height: width
                        }
                        Rectangle {
                            id: headingHandleRect
                            height: childrenRect.height
                            width: childrenRect.width
                            radius: 3
                            x: headingHandleNub.x - width / 2 + headingHandleNub.width / 2
                            y: headingHandleNub.y - height
                            color: opacitySlider.background.children[0].color

                            Text {
                                id: headingValue
                                font.pixelSize: 14
                                padding: 3
                                horizontalAlignment: Qt.AlignHCenter
                                verticalAlignment: Qt.AlignVCenter
                                text: "opacity: " + (opacitySlider.value).toFixed(2)
                                color: "white"
                            }
                        }
                    }
                }

                RowLayout {
                    id: bottomRowControls
                    spacing: 2
                    Button {
                        id: startStopBtn
                        text: !timer.running ? qsTr("Start") : qsTr("Stop")
                        Layout.minimumWidth: timerIntervalComboBox.width
                        onClicked: {
                            if (!timer.running)
                                timer.start();
                            else
                                timer.stop();
                        }
                    }

                    ComboBox {
                        id: timerIntervalComboBox
                        currentIndex: 2
                        model: imageFrameRefreshRate
                        Layout.minimumWidth: startStopBtn.width

                        onActivated: timer.interval = timerIntervals[currentIndex];
                    }
                }
            }
        }
    }

    // create an envelope of the pacific southwest sector for displaying the image frame
    Envelope {
        id: imageFrameExtent
        xMin: -127.62
        xMax: -112.524
        yMin: 27.9425
        yMax: 42.3195
        spatialReference: SpatialReference { wkid: 4326 }
    }

    // Create file folder to find image file names
    FileFolder {
        id: imageFrameFolder
        url: dataPath

        Component.onCompleted: fileNamesLength = imageFrameFolder.fileNames().length;
    }
}