QCameraFocus Class

Some hardware supports a movable focus lens assembly, and typically this hardware also supports automatically focusing via some heuristic. You can influence this via the FocusPointMode setting - typically the center of the frame is brought into focus, but some hardware also supports focusing on any faces detected in the frame, or on a specific point (usually provided by a user in a "touch to focus" scenario).

This class (in combination with QCameraFocusZone) can expose information on what parts of the camera sensor image are in focus or are being used for autofocusing via the focusZones() property:

focus->setFocusPointMode(QCameraFocus::FocusPointAuto);
QList<QCameraFocusZone> zones = focus->focusZones();
foreach (QCameraFocusZone zone, zones) {
    if (zone.status() == QCameraFocusZone::Focused) {
        // Draw a green box at zone.area()
    } else if (zone.status() == QCameraFocusZone::Selected) {
        // This area is selected for autofocusing, but is not in focus
        // Draw a yellow box at zone.area()
    }
}

See also QCameraFocusZone

flags QCameraFocus::FocusModes

The FocusModes type is a typedef for QFlags<FocusMode>. It stores an OR combination of FocusMode values.

This property represents the position of the custom focus point, in relative frame coordinates: QPointF(0,0) points to the left top frame point, QPointF(0.5,0.5) points to the frame center.

The custom focus point property is used only in FocusPointCustom focus mode.

Access functions:

• customFocusPoint() const

• void setCustomFocusPoint(const &point)

This property holds the current digital zoom value.

Access functions:

• digitalZoom() const

Notifier signal:

• void digitalZoomChanged( value)

See Also▲

This property holds the current camera focus mode.

This controls the way the camera lens assembly is configured.

Access functions:

• focusMode() const

• void setFocusMode( mode)

See Also▲

This property holds the current camera focus point selection mode.

If the camera focus mode is set to use an autofocusing mode, this property controls the way the camera will select areas of the frame to use for autofocusing.

Access functions:

• focusPointMode() const

• void setFocusPointMode( mode)

See Also▲

Returns the list of active focus zones.

If QCamera::FocusPointAuto or QCamera::FocusPointFaceDetection focus mode is selected this method returns the list of zones the camera is actually focused on.

The coordinates system is the same as for custom focus points: QPointF(0,0) points to the left top frame point, QPointF(0.5,0.5) points to the frame center.

Access functions:

• QCameraFocusZoneList focusZones() const

Notifier signal:

• void focusZonesChanged()

This property holds the current optical zoom value.

Access functions:

• opticalZoom() const

Notifier signal:

• void opticalZoomChanged( value)

See Also▲

Signal emitted when digital zoom value changes to new value.

This signal is emitted when the set of zones used in autofocusing is changed.

This can change when a zone is focused or loses focus, or new focus zones have been detected.

Returns true if focus related settings are supported by this camera.

You may need to also check if any specific features are supported.

Returns true if the focus mode is supported by camera.

Returns true if focus point mode is supported.

Returns the maximum digital zoom

This will be 1.0 on cameras that do not support digital zoom.

Signal emitted when the maximum supported digital zoom value changed.

The maximum supported zoom value can depend on other camera settings, like capture mode or resolution.

Returns the maximum optical zoom.

This will be 1.0 on cameras that do not support optical zoom.

Signal emitted when the maximum supported optical zoom value changed.

Signal emitted when optical zoom value changes to new value.

Set the camera optical and digital zoom values.

Since there may be a physical component to move, the change in zoom value may not be instantaneous.