CameraFocus QML Type

An interface for focus related camera settings.

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Publié le 27 décembre 2024 - Mis à jour le 27 décembre 2024

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CameraFocus QML Type▲

Import Statement: import QtMultimedia 5.12
Group: CameraFocus is part of multimedia_qml, camera_qml

Detailed Description▲

This type allows control over manual and automatic focus settings, including information about any parts of the camera frame that are selected for autofocusing.

It should not be constructed separately, instead the focus property of a Camera should be used.

Sélectionnez

Item {
    width: 640
    height: 360

    Camera {
        id: camera

        focus {
            focusMode: Camera.FocusMacro
            focusPointMode: Camera.FocusPointCustom
            customFocusPoint: Qt.point(0.2, 0.2) // Focus relative to top-left corner
        }
    }

    VideoOutput {
        source: camera
        anchors.fill: parent
    }
}

Property Documentation▲

customFocusPoint : point▲

This property holds the position of 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.

Custom focus point is used only in FocusPointCustom focus mode.

focusMode : enumeration▲

This property holds the current camera focus mode, which can be one of the following values:

Value	Description
FocusManual	Manual or fixed focus mode.
FocusHyperfocal	Focus to hyperfocal distance, with the maximum depth of field achieved. All objects at distances from half of this distance out to infinity will be acceptably sharp.
FocusInfinity	Focus strictly to infinity.
FocusAuto	One-shot auto focus mode.
FocusContinuous	Continuous auto focus mode.
FocusMacro	One shot auto focus to objects close to camera.

It's possible to combine multiple Camera::FocusMode values, for example Camera.FocusMacro + Camera.FocusContinuous.

In automatic focusing modes, the focusPointMode property and focusZones property provide information and control over how automatic focusing is performed.

focusPointMode : enumeration▲

This property holds the current camera focus point mode. It is used in automatic focusing modes to determine what to focus on. If the current focus point mode is Camera.FocusPointCustom, the customFocusPoint property allows you to specify which part of the frame to focus on.

The property can take one of the following values:

Value	Description
FocusPointAuto	Automatically select one or multiple focus points.
FocusPointCenter	Focus to the frame center.
FocusPointFaceDetection	Focus on faces in the frame.
FocusPointCustom	Focus to the custom point, defined by the customFocusPoint property.

[read-only] focusZones : list<focusZone>▲

This property holds the list of current camera focus zones, each including area specified in the same coordinates as customFocusPoint, and zone status as one of the following values:

Value	Description
Camera.FocusAreaUnused	This focus point area is currently unused in autofocusing.
Camera.FocusAreaSelected	This focus point area is used in autofocusing, but is not in focus.
Camera.FocusAreaFocused	This focus point is used in autofocusing, and is in focus.

Sélectionnez

VideoOutput {
    id: viewfinder
    source: camera

    //display focus areas on camera viewfinder:
    Repeater {
          model: camera.focus.focusZones

          Rectangle {
              border {
                  width: 2
                  color: status == Camera.FocusAreaFocused ? "green" : "white"
              }
              color: "transparent"

              // Map from the relative, normalized frame coordinates
              property variant mappedRect: viewfinder.mapNormalizedRectToItem(area);

              x: mappedRect.x
              y: mappedRect.y
              width: mappedRect.width
              height: mappedRect.height
          }
    }
}

[read-only, since 5.11] supportedFocusModes : list<FocusMode>▲

This property holds the supported focus modes of the camera.

This property was introduced in Qt 5.11.

[read-only, since 5.10] supportedFocusPointModes : list<enumeration>▲

This property holds the supported focus point modes of the camera.

This property was introduced in Qt 5.10.

Obsolete Members for CameraFocus▲

The following members of QML type CameraFocus are deprecated. We strongly advise against using them in new code.

Obsolete Method Documentation▲

bool isFocusModeSupported(mode)▲

This method is deprecated. We strongly advise against using it in new code.

Returns true if the supplied mode is a supported focus mode, and false otherwise.

bool isFocusPointModeSupported(mode)▲