With QtQuick 2 reloading of (remote) images that was pretty unnoticable with QtQuick 1 causes flickering now.

Looks like the reason is QQuickImageBase::load() calling update right after triggering the reload (there's a comment explaining why). As the image is not yet available this results in "nothing" to be drawn (= flicker) until image loading has been completed.

Maybe QQuickImageBase should apply some kind of double buffering, e.g. using two alternating QQuickPixmap instances.

Here's some example code reloading a webcam image every five seconds:

import QtQuick 2.12
import QtQuick.Window 2.12

Window {
  visible: true
  width: 640
  height: 480
  title: qsTr("Webcam Flicker")

  property int counter

  Image {
    anchors.fill: parent
    source: "https://www.bicos.de/webcam/webcam4.jpg?ts=" + counter
  }

  Timer {
    interval: 5000
    repeat: true
    onTriggered: counter++;
    running: true
  }
}