Source code

imgObj.onload = function() {
        //Get Image in Center of Screen.
        let leftPointX = this.width / 2 - imageWidth/2;
        let leftPointY = this.height / 2 - imageHeight/2;

        //clip circle frame.
        ctx.arc(imageWidth/2, imageWidth/2, imageWidth/2, 0, 2 * Math.PI, false);
        ctx.clip();

        //Get context data from source image.
        ctx.drawImage(imgObj, leftPointX, leftPointY, imageWidth, imageHeight, 0, 0, imageWidth, imageHeight);
        fnBlur();

        let imageData = canvas.toDataURL("image/png");

        let scaleWidth = krpano.get("view.fov")  * window.devicePixelRatio;
        let scaleHeight = krpano.get("view.fov") * window.devicePixelRatio;

        console.log(krpano.get("stagescale"));
        //console.log(document.getElementById('krpanoSWFObject').offsetWidth);
        //console.log(document.getElementById('krpanoSWFObject').offsetHeight);

        krpano.set("hotspot['tests'].url", imageData);
        krpano.set("hotspot['tests'].ath", krpano.get('view.hlookat'));
        krpano.set("hotspot['tests'].atv", krpano.get('view.vlookat'));
        krpano.set("hotspot['tests'].width", scaleWidth);
        krpano.set("hotspot['tests'].height", scaleWidth);

        krpano.call('updatescreen();');
}