QML svg antialiasing example.

component.qml

LogoImage {
      id: distroLogo
      Layout.minimumWidth: (implicitWidth < implicitHeight) ? 100*implicitWidth/implicitHeight : 100
      Layout.minimumHeight: (implicitHeight < implicitWidth) ? 100*implicitHeight/implicitWidth : 100
      Layout.preferredWidth: (Layout.fillWidth) ? Layout.minimumWidth : height * implicitWidth/implicitHeight
      Layout.preferredHeight: (Layout.fillHeight) ? Layout.minimumHeight : width * implicitHeight/implicitWidth
      Layout.fillWidth: (implicitWidth < implicitHeight) ? false: true
      Layout.fillHeight: !Layout.fillWidth
      Layout.alignment: Qt.AlignCenter

      image.source: "../" + Code.getStandardLogo(logo, osInfoItem.distroId)
      image.sourceSize.width: parent.width                                          // This line is important
      image.sourceSize.height: parent.height                                        // This line is important
      image.smooth:true                                                             // This line is important
      image.antialiasing: true                                                      // This line is important
      fillScale: plasmoid.configuration.logoScale
      onFillScaleChanged: if (fillScale !== plasmoid.configuration.logoScale) plasmoid.configuration.logoScale = fillScale

      MouseArea {
          anchors.fill: parent
          acceptedButtons: Qt.RightButton
          onClicked: logoPopup.open(mouse.x, mouse.y)
      }

      PlasmaComponents.ContextMenu {
          id: logoPopup

          PlasmaComponents.MenuItem {
              text: distroLogo.editMode ? i18n("Lock image scaling") : i18n("Unlock image scaling")
              onClicked: distroLogo.editMode = !distroLogo.editMode
          }
      }
}