QImageCapture Class

QMediaCaptureSession captureSession;
camera = new QCamera;
captureSession.setCamera(camera);

viewfinder = new QVideoWidget;
viewfinder->show();
captureSession.setVideoOutput(viewfinder);

imageCapture = new QImageCapture;
captureSession.setImageCapture(imageCapture);

camera->start();
// on shutter button pressed
imageCapture->capture();

Member Function Documentation

[explicit] QImageCapture::QImageCapture(QObject *parent = nullptr)

Constructs a image capture object, from a parent, that can capture individual still images produced by a camera.

You must connect both an image capture object and a QCamera to a capture session to capture images.

[override virtual noexcept] QImageCapture::~QImageCapture()

Destroys images capture object.

void QImageCapture::addMetaData(const QMediaMetaData &metaData)

Adds additional metaData to any existing meta data, that is embedded into the captured image.

[slot] int QImageCapture::capture()

Capture the image and make it available as a QImage. This operation is asynchronous in majority of cases, followed by signals QImageCapture::imageExposed(), QImageCapture::imageCaptured() or QImageCapture::error().

QImageCapture::capture returns the capture Id parameter, used with imageExposed(), imageCaptured() and imageSaved() signals.

See also isReadyForCapture().

QMediaCaptureSession *QImageCapture::captureSession() const

Returns the capture session this camera is connected to, or a nullptr if the camera is not connected to a capture session.

Use QMediaCaptureSession::setImageCapture() to connect the image capture to a session.

[slot] int QImageCapture::captureToFile(const QString &file = QString())

Capture the image and save it to file. This operation is asynchronous in majority of cases, followed by signals QImageCapture::imageExposed(), QImageCapture::imageCaptured(), QImageCapture::imageSaved() or QImageCapture::error().

If an empty file is passed, the camera back end chooses the default location and naming scheme for photos on the system, if only file name without full path is specified, the image will be saved to the default directory, with a full path reported with imageCaptured() and imageSaved() signals.

QCamera saves all the capture parameters like exposure settings or image processing parameters, so changes to camera parameters after capture() is called do not affect previous capture requests.

QImageCapture::capture returns the capture Id parameter, used with imageExposed(), imageCaptured() and imageSaved() signals.

See also isReadyForCapture().

[signal] void QImageCapture::errorOccurred(int id, QImageCapture::Error error, const QString &errorString)

Signals that the capture request id has failed with an error and errorString description.

[static] QString QImageCapture::fileFormatDescription(QImageCapture::FileFormat f)

Returns the description of the given file format, f.

[static] QString QImageCapture::fileFormatName(QImageCapture::FileFormat f)

Returns the name of the given format, f.

[signal] void QImageCapture::imageAvailable(int id, const QVideoFrame &frame)

Signal emitted when the frame with request id is available.

[signal] void QImageCapture::imageCaptured(int id, const QImage &preview)

Signal emitted when the frame with request id was captured, but not processed and saved yet. Frame preview can be displayed to user.

[signal] void QImageCapture::imageExposed(int id)

Signal emitted when the frame with request id was exposed.

[signal] void QImageCapture::imageMetadataAvailable(int id, const QMediaMetaData &metaData)

Signals that an image identified by id has metaData.

[signal] void QImageCapture::imageSaved(int id, const QString &fileName)

Signal emitted when QImageCapture::CaptureToFile is set and the frame with request id was saved to fileName.

bool QImageCapture::isAvailable() const

Returns true if the images capture service ready to use.

[signal] void QImageCapture::readyForCaptureChanged(bool ready)

Signals that a camera's ready for capture state has changed.

void QImageCapture::resetResolution()

Resets the requested resolution of captured images to the default.

See also setResolution().

[signal] void QImageCapture::resolutionChanged()

Signals when the image resolution changes.

void QImageCapture::setFileFormat(QImageCapture::FileFormat format)

Sets the image format.

Assigning an unsupported FileFormat has no effect.

See also fileFormat() and supportedFormats.

void QImageCapture::setMetaData(const QMediaMetaData &metaData)

Replaces any existing meta data, to be embedded into the captured image, with a set of metaData.

See also metaData().

void QImageCapture::setQuality(QImageCapture::Quality quality)

Sets the image encoding quality.

See also quality().

void QImageCapture::setResolution(const QSize &resolution)

Sets the requested resolution of captured images.

An empty QSize indicates the backend should make an optimal choice based on what is available from the image source.

See also resolution().

void QImageCapture::setResolution(int width, int height)

Sets the width and height of the requested resolution of captured images.

[static] QList<QImageCapture::FileFormat> QImageCapture::supportedFormats()

Returns a list of supported file formats.

See also FileFormat.