ImageAttributes QML Type

(BETA) Allows storing of additional metadata in JEPG images. More...

• List of all members, including inherited members

Properties

• appMarker : int
• destFilePath : string
• destFileUrl : url
• filePath : string
• fileUrl : url
• signature : string
• version : ushort

Methods

• object keys()
• bool loadValueFromFile(string key, url fileUrl)
• bool loadValueFromFile(string key, string filePath)
• remove(qstringlist keys)
• remove(string key)
• removeAll()
• bool saveValueToFile(string key, url fileUrl)
• bool saveValueToFile(string key, string filePath)
• bool setValue(string key, object value)
• bool setValues(object values)
• object value(string key)
• object values(qstringlist keys)
• object values()
• object values(string key)

Detailed Description

The ImageAttributes component is used for reading and writing medadata in JPEG images stored in custom JPEG APPn markers.

The following code sample sets a number of example metadata values, before printing them in the console log.

ImageAttributes {
    id: imageAttributes
    filePath: "~/ArcGIS/Data/Pictures/Esri.jpg"
    Component.onCompleted: {
        imageAttributes.setValue("data.json", {"address":"380 New York Street","name":"ESRI"});
        imageAttributes.setValue("brownfox.txt", "The quick brown fox jumped over the lazy dog.\n");
        imageAttributes.loadValueFromFile("jack.jpg", "~/ArcGIS/Data/Pictures/jack2.jpg");
        let _keys = imageAttributes.keys();
        console.log("imageAttributes.keys: ", JSON.stringify(_keys)); // ["data.json","brownfox.txt","jack.jpg"]
        let data = imageAttributes.value("data.json");
        console.log("typeof(data): ", typeof data); // object
        console.log("data: ", JSON.stringify(data)); // {"address":"380 New York Street","name":"ESRI"}
        let brownfox = imageAttributes.value("brownfox.txt");
        console.log("typeof(brownfox): ", typeof brownfox); // string
        console.log("brownfox: ", JSON.stringify(brownfox)); // "The quick brown fox jumped over the lazy dog.\n"
        let image = imageAttributes.value("jack.jpg");
        console.log(typeof("typeof(image): ", typeof image)); // object
        console.log("image instanceof ArrayBuffer: ", image instanceof ArrayBuffer); // true
        console.log("image.byteLength: ", image.byteLength); // 533643
        let values = imageAttributes.values();
        console.log("imageAttributes.values(): ", JSON.stringify(values)); // {"brownfox.txt":"The quick brown fox jumped over the lazy dog.\n","data.json":{"address":"380 New York Street","name":"ESRI"},"jack.jpg":"blob://imageattributes/jack.jpg"}
        let notExists = imageAttributes.value("notexist.txt");
        console.log("typeof(notExists): ", typeof(notExists)); // undefined
        console.log("notExists: ", JSON.stringify(notExists)); // undefined
        let ok = imageAttributes.saveValueToFile("jack.jpg", "~/ArcGIS/Data/Pictures/Jack2.jpg");
        console.log("imageAttributes.saveValueToFile: ", JSON.stringify(ok)); // true
    }
}

Property Documentation

Method Documentation