QImageCapture Class▲
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Header: QImageCapture
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CMake:
find_package(Qt6 REQUIRED COMPONENTS Multimedia)
target_link_libraries(mytarget PRIVATE Qt6::Multimedia)
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qmake: QT += multimedia
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Inherits: QObject
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Inherited By:
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Group: QImageCapture is part of multimedia, multimedia_camera
Detailed Description▲
The QImageCapture class is a high level images recording class. It's not intended to be used alone but for accessing the media recording functions of other media objects, like QCamera.
QMediaCaptureSession captureSession;
camera = new QCamera;
captureSession.setCamera(camera);
viewfinder = new QVideoWidget();
viewfinder->show();
captureSession.setVideoOutput(viewfinder);
imageCapture = new QImageCapture(camera);
captureSession.setImageCapture(imageCapture);
camera->start();
//on shutter button pressed
imageCapture->capture();See Also▲
See also QCamera
Member Type Documentation▲
enum QImageCapture::Error▲
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Constant |
Value |
Description |
|---|---|---|
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QImageCapture::NoError |
0 |
No Errors. |
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QImageCapture::NotReadyError |
1 |
The service is not ready for capture yet. |
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QImageCapture::ResourceError |
2 |
Device is not ready or not available. |
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QImageCapture::OutOfSpaceError |
3 |
No space left on device. |
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QImageCapture::NotSupportedFeatureError |
4 |
Device does not support stillimages capture. |
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QImageCapture::FormatError |
5 |
Current format is not supported. |
enum QImageCapture::FileFormat▲
Choose one of the following image formats:
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Constant |
Value |
Description |
|---|---|---|
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QImageCapture::UnspecifiedFormat |
0 |
No format specified |
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QImageCapture::JPEG |
1 |
.jpg or .jpeg format |
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QImageCapture::PNG |
2 |
.png format |
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QImageCapture::WebP |
3 |
.webp format |
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QImageCapture::Tiff |
4 |
.tiff format |
enum QImageCapture::Quality▲
Enumerates quality encoding levels.
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Constant |
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QImageCapture::VeryLowQuality |
0 |
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QImageCapture::LowQuality |
1 |
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QImageCapture::NormalQuality |
2 |
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QImageCapture::HighQuality |
3 |
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QImageCapture::VeryHighQuality |
4 |
Property Documentation▲
[read-only] error : const Error▲
Returns the current error state.
Access functions:
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error() const
Notifier signal:
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void errorChanged()
See Also▲
See also errorString()
[read-only] errorString : const QString▲
Returns a string describing the current error state.
Access functions:
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errorString() const
Notifier signal:
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void errorChanged()
See Also▲
See also error()
[read-only] fileFormat : const FileFormat▲
This property holds the image format.
Access functions:
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fileFormat() const
Notifier signal:
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void fileFormatChanged()
metaData : QMediaMetaData▲
This property holds the meta data that will get embedded into the image.
Additional fields such as a time stamp or location may get added by the camera back end.
Access functions:
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metaData() const
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void setMetaData(const &metaData)
Notifier signal:
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void metaDataChanged()
[read-only] quality : const Quality▲
This property holds the image encoding quality.
Access functions:
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quality() const
Notifier signal:
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void qualityChanged()
[read-only] readyForCapture : const bool▲
Holds true if the camera is ready to capture an image immediately. Calling capture() while readyForCapture is false is not permitted and results in an error.
Access functions:
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bool isReadyForCapture() const
Notifier signal:
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void readyForCaptureChanged(bool ready)
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.
[virtual] 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.
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▲
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.
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▲
See also isReadyForCapture()
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.
void QImageCapture::imageAvailable(int id, const QVideoFrame &frame)▲
Signal emitted when the frame with request id is available.
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.
void QImageCapture::imageExposed(int id)▲
Signal emitted when the frame with request id was exposed.
void QImageCapture::imageMetadataAvailable(int id, const QMediaMetaData &metaData)▲
Signals that an image identified by id has metaData.
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.
void QImageCapture::readyForCaptureChanged(bool ready)▲
Signals that a camera's ready for capture state has changed.
Notifier signal for property readyForCapture.
QSize QImageCapture::resolution() const▲
void QImageCapture::resolutionChanged()▲
Signals when the image resolution changes.
void QImageCapture::setFileFormat(QImageCapture::FileFormat format)▲
void QImageCapture::setMetaData(const QMediaMetaData &metaData)▲
Replaces any existing meta data, to be embedded into the captured image, with a set of metaData.
Setter function for property metaData.
See Also▲
See also metaData()
void QImageCapture::setQuality(QImageCapture::Quality quality)▲
void QImageCapture::setResolution(const QSize &resolution)▲
Sets the resolution of the encoded image.
An empty QSize indicates the encoder should make an optimal choice based on what is available from the image source and the limitations of the codec.
See Also▲
See also resolution()
void QImageCapture::setResolution(int width, int height)▲
Sets the width and height of the resolution of the encoded image.
This is an overloaded function.