- class QCamera#
The
QCamera
class provides interface for system camera devices. More…Synopsis#
Properties#
exposureCompensationᅟ
- Exposure compensation in EV unitsexposureModeᅟ
- Exposure mode being usedexposureTimeᅟ
- Camera’s exposure time in secondsflashModeᅟ
- Flash mode being usedflashReadyᅟ
- Indicates if the flash is charged and ready to usefocusModeᅟ
- The current camera focus modeisoSensitivityᅟ
- Sensor ISO sensitivitymanualIsoSensitivityᅟ
- Describes a manually set ISO sensitivitytorchModeᅟ
- Torch mode being usedzoomFactorᅟ
- Current zoom factor
Methods#
def
__init__()
def
cameraDevice()
def
cameraFormat()
def
captureSession()
def
error()
def
errorString()
def
exposureMode()
def
exposureTime()
def
flashMode()
def
focusDistance()
def
focusMode()
def
focusPoint()
def
isActive()
def
isAvailable()
def
isFlashReady()
def
isoSensitivity()
def
setFocusMode()
def
setZoomFactor()
def
torchMode()
def
zoomFactor()
Slots#
def
setActive()
def
setFlashMode()
def
setTorchMode()
def
start()
def
stop()
def
zoomTo()
Signals#
def
activeChanged()
def
errorChanged()
def
errorOccurred()
def
flashReady()
def
hueChanged()
Note
This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE
Detailed Description#
Warning
This section contains snippets that were automatically translated from C++ to Python and may contain errors.
QCamera
can be used within aQMediaCaptureSession
for video recording and image taking.You can use
QCameraDevice
to list available cameras and choose which one to use.cameras = QMediaDevices.videoInputs() for cameraDevice in cameras: if cameraDevice.description() == "mycamera": camera = QCamera(cameraDevice)
On hardware that supports it,
QCamera
lets you adjust the focus and zoom. This also includes functionality such as a “Macro” mode for close up work (e.g. reading barcodes, or recognizing letters), or “touch to focus” - indicating an interesting area of the image for the hardware to attempt to focus on.camera.setFocusPointMode(QCamera.FocusModeManual) camera.setCustomFocusPoint(QPointF(0.25f, 0.75f)) # A point near the bottom left, 25% away from the corner, near that shiny vase
The
minimumZoomFactor()
andmaximumZoomFactor()
methods provide the range of supported zoom factors. ThezoomTo()
method allows changing the zoom factor.camera.setZoomFactor(3.0)
After capturing the raw data for a camera frame, the camera hardware and software performs various image processing tasks to produce the final image. This includes compensating for ambient light color, reducing noise, as well as making some other adjustments to the image.
You can control many of these processing steps through the Camera properties. For example, you can set the white balance (or color temperature) used for processing images:
camera.setWhiteBalanceMode(QCamera.WhiteBalanceFluorescent)
For more information on image processing of camera frames, see Camera Image Processing .
See the camera overview for more information.
- class Error#
This enum holds the last error code.
Constant
Description
QCamera.NoError
No errors have occurred.
QCamera.CameraError
An error has occurred.
- class FocusMode#
Constant
Description
QCamera.FocusModeAuto
Continuous auto focus mode.
QCamera.FocusModeAutoNear
Continuous auto focus mode on near objects.
QCamera.FocusModeAutoFar
Continuous auto focus mode on objects far away.
QCamera.FocusModeHyperfocal
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.
QCamera.FocusModeInfinity
Focus strictly to infinity.
QCamera.FocusModeManual
Manual or fixed focus mode.
New in version 6.1.
- class FlashMode#
Constant
Description
QCamera.FlashOff
Flash is Off.
QCamera.FlashOn
Flash is On.
QCamera.FlashAuto
Automatic flash.
New in version 6.1.
- class TorchMode#
Constant
Description
QCamera.TorchOff
Torch is Off.
QCamera.TorchOn
Torch is On.
QCamera.TorchAuto
Automatic torch.
New in version 6.1.
- class ExposureMode#
Constant
Description
QCamera.ExposureAuto
Automatic mode.
QCamera.ExposureManual
Manual mode.
QCamera.ExposurePortrait
Portrait exposure mode.
QCamera.ExposureNight
Night mode.
QCamera.ExposureSports
Spots exposure mode.
QCamera.ExposureSnow
Snow exposure mode.
QCamera.ExposureBeach
Beach exposure mode.
QCamera.ExposureAction
Action mode. Since 5.5
QCamera.ExposureLandscape
Landscape mode. Since 5.5
QCamera.ExposureNightPortrait
Night portrait mode. Since 5.5
QCamera.ExposureTheatre
Theatre mode. Since 5.5
QCamera.ExposureSunset
Sunset mode. Since 5.5
QCamera.ExposureSteadyPhoto
Steady photo mode. Since 5.5
QCamera.ExposureFireworks
Fireworks mode. Since 5.5
QCamera.ExposureParty
Party mode. Since 5.5
QCamera.ExposureCandlelight
Candlelight mode. Since 5.5
QCamera.ExposureBarcode
Barcode mode. Since 5.5
New in version 6.1.
- class WhiteBalanceMode#
Constant
Description
QCamera.WhiteBalanceAuto
Auto white balance mode.
QCamera.WhiteBalanceManual
Manual white balance. In this mode the white balance should be set with
setColorTemperature()
QCamera.WhiteBalanceSunlight
Sunlight white balance mode.
QCamera.WhiteBalanceCloudy
Cloudy white balance mode.
QCamera.WhiteBalanceShade
Shade white balance mode.
QCamera.WhiteBalanceTungsten
Tungsten (incandescent) white balance mode.
QCamera.WhiteBalanceFluorescent
Fluorescent white balance mode.
QCamera.WhiteBalanceFlash
Flash white balance mode.
QCamera.WhiteBalanceSunset
Sunset white balance mode.
New in version 6.1.
- class Feature#
(inherits
enum.Flag
) Describes a set of features supported by the camera. The returned value can be a combination of:Constant
Description
QCamera.Feature.ColorTemperature
The Camera supports setting a custom
colorTemperature
.QCamera.Feature.ExposureCompensation
The Camera supports setting a custom
exposureCompensation
.QCamera.Feature.IsoSensitivity
The Camera supports setting a custom
isoSensitivity
.QCamera.Feature.ManualExposureTime
The Camera supports setting a
manual exposure Time
.QCamera.Feature.CustomFocusPoint
The Camera supports setting a
custom focus point
.QCamera.Feature.FocusDistance
The Camera supports setting the
focusDistance
property.New in version 6.1.
Note
Properties can be used directly when
from __feature__ import true_property
is used or via accessor functions otherwise.- property activeᅟ: bool#
Describes whether the camera is currently active.
- Access functions:
Signal
activeChanged()
- property cameraDeviceᅟ: QCameraDevice#
Returns the
QCameraDevice
object associated with this camera.- Access functions:
- property cameraFormatᅟ: QCameraFormat#
Returns the camera format currently used by the camera.
Note
When using the FFMPEG backend on an Android target device if you request YUV420P format, you will receive either a fully planar 4:2:0 YUV420P or a semi-planar NV12/NV21. This depends on the codec implemented by the device OEM.
See also
- Access functions:
- property colorTemperatureᅟ: int#
Returns the current color temperature if the current white balance mode is
WhiteBalanceManual
. For other modes the return value is undefined.- Access functions:
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.You can check whether custom focus points are supported by querying
supportedFeatures()
with the Feature.CustomFocusPoint
flag.- Access functions:
- property errorᅟ: QCamera.Error#
Returns the error state of the camera.
- Access functions:
Signal
errorChanged()
- property errorStringᅟ: str#
Returns a human readable string describing a camera’s error state.
- Access functions:
Signal
errorChanged()
- property exposureCompensationᅟ: float#
This property holds Exposure compensation in EV units..
Exposure compensation property allows to adjust the automatically calculated exposure.
- Access functions:
- property exposureModeᅟ: QCamera.ExposureMode#
This property holds The exposure mode being used..
See also
- Access functions:
- property exposureTimeᅟ: float#
This property holds Camera’s exposure time in seconds..
- Access functions:
- property flashModeᅟ: QCamera.FlashMode#
This property holds The flash mode being used..
Enables a certain flash mode if the camera has a flash.
See also
- Access functions:
- property flashReadyᅟ: bool#
This property holds Indicates if the flash is charged and ready to use..
- Access functions:
Signal
flashReady()
- property focusDistanceᅟ: float#
This property return an approximate focus distance of the camera. The value reported is between 0 and 1, 0 being the closest possible focus distance, 1 being as far away as possible. Note that 1 is often, but not always infinity.
Setting the focus distance will be ignored unless the focus mode is set to
FocusModeManual
.- Access functions:
- property focusModeᅟ: QCamera.FocusMode#
This property holds the current camera focus mode..
Sets up different focus modes for the camera. All auto focus modes will focus continuously. Locking the focus is possible by setting the focus mode to
FocusModeManual
. This will keep the current focus and stop any automatic focusing.See also
- Access functions:
Returns the point currently used by the auto focus system to focus onto.
- Access functions:
Signal
focusPointChanged()
- property isoSensitivityᅟ: int#
This property holds The sensor ISO sensitivity..
Describes the ISO sensitivity currently used by the camera.
- Access functions:
- property manualExposureTimeᅟ: int#
Set the manual exposure time to
seconds
- Access functions:
- property manualIsoSensitivityᅟ: int#
This property Describes a manually set ISO sensitivity.
Setting this property to -1 (the default), implies that the camera automatically adjusts the ISO sensitivity.
- Access functions:
- property maximumZoomFactorᅟ: float#
Returns the maximum zoom factor.
This will be
1.0
on cameras that do not support zooming.- Access functions:
- property minimumZoomFactorᅟ: float#
Returns the minimum zoom factor.
This will be
1.0
on cameras that do not support zooming.- Access functions:
- property supportedFeaturesᅟ: Combination of QCamera.Feature#
Returns the features supported by this camera.
See also
- Access functions:
- property torchModeᅟ: QCamera.TorchMode#
This property holds The torch mode being used..
A torch is a continuous source of light. It can be used during video recording in low light conditions. Enabling torch mode will usually override any currently set flash mode.
See also
- Access functions:
- property whiteBalanceModeᅟ: QCamera.WhiteBalanceMode#
Returns the white balance mode being used.
- Access functions:
- property zoomFactorᅟ: float#
This property holds The current zoom factor..
Gets or sets the current zoom factor. Values will be clamped between
minimumZoomFactor
andmaximumZoomFactor
.- Access functions:
Construct a
QCamera
with aparent
.Selects the default camera on the system if more than one camera is available.
Construct a
QCamera
which uses a hardware camera located a the specifiedposition
.For example on a mobile phone it can be used to easily choose between front-facing and back-facing cameras.
If no camera is available at the specified
position
or ifposition
isUnspecifiedPosition
, the default camera is used.- __init__(cameraDevice[, parent=None])
- Parameters:
cameraDevice –
QCameraDevice
parent –
QObject
Construct a
QCamera
from a camera descriptioncameraDevice
andparent
.- activeChanged(arg__1)#
- Parameters:
arg__1 – bool
Notification signal of property
activeᅟ
.- brightnessChanged()#
- cameraDevice()#
- Return type:
See also
Getter of property
cameraDeviceᅟ
.- cameraDeviceChanged()#
Notification signal of property
cameraDeviceᅟ
.- cameraFormat()#
- Return type:
See also
Getter of property
cameraFormatᅟ
.- cameraFormatChanged()#
Notification signal of property
cameraFormatᅟ
.- captureSession()#
- Return type:
Returns the capture session this camera is connected to, or a nullptr if the camera is not connected to a capture session.
use
setCamera()
to connect the camera to a session.- colorTemperature()#
- Return type:
int
See also
Getter of property
colorTemperatureᅟ
.- colorTemperatureChanged()#
Notification signal of property
colorTemperatureᅟ
.- contrastChanged()#
- customFocusPoint()#
- Return type:
See also
Getter of property
customFocusPointᅟ
.- customFocusPointChanged()#
Notification signal of property
customFocusPointᅟ
.Getter of property
errorᅟ
.- errorChanged()#
Notification signal of property
errorᅟ
.This signal is emitted when error state changes to
error
. A description of the error is provided aserrorString
.- errorString()#
- Return type:
str
Getter of property
errorStringᅟ
.- exposureCompensation()#
- Return type:
float
See also
Getter of property
exposureCompensationᅟ
.- exposureCompensationChanged(arg__1)#
- Parameters:
arg__1 – float
Signal emitted when the exposure compensation changes to
value
.Notification signal of property
exposureCompensationᅟ
.- exposureMode()#
- Return type:
See also
Getter of property
exposureModeᅟ
.- exposureModeChanged()#
Notification signal of property
exposureModeᅟ
.- exposureTime()#
- Return type:
float
Returns the current exposure time in seconds.
Getter of property
exposureTimeᅟ
.- exposureTimeChanged(speed)#
- Parameters:
speed – float
Signals that a camera’s exposure
speed
has changed.Notification signal of property
exposureTimeᅟ
.- flashMode()#
- Return type:
See also
Getter of property
flashModeᅟ
.- flashModeChanged()#
Notification signal of property
flashModeᅟ
.- flashReady(arg__1)#
- Parameters:
arg__1 – bool
Signal the flash
ready
status has changed.Notification signal of property
flashReadyᅟ
.- focusDistance()#
- Return type:
float
See also
Getter of property
focusDistanceᅟ
.- focusDistanceChanged(arg__1)#
- Parameters:
arg__1 – float
Notification signal of property
focusDistanceᅟ
.- focusMode()#
- Return type:
See also
Getter of property
focusModeᅟ
.- focusModeChanged()#
Signals when the
focusMode
changes.Getter of property
focusPointᅟ
.- focusPointChanged()#
Notification signal of property
focusPointᅟ
.- hueChanged()#
- isActive()#
- Return type:
bool
Returns true if the camera is currently active.
Getter of property
activeᅟ
.- isAvailable()#
- Return type:
bool
Returns true if the camera can be used.
- isExposureModeSupported(mode)#
- Parameters:
mode –
ExposureMode
- Return type:
bool
Returns true if the exposure
mode
is supported.Returns true if the flash
mode
is supported.- isFlashReady()#
- Return type:
bool
Returns true if flash is charged.
Getter of property
flashReadyᅟ
.Returns true if the focus
mode
is supported by the camera.Returns true if the torch
mode
is supported.- isWhiteBalanceModeSupported(mode)#
- Parameters:
mode –
WhiteBalanceMode
- Return type:
bool
Returns true if the white balance
mode
is supported.- isoSensitivity()#
- Return type:
int
Getter of property
isoSensitivityᅟ
.- isoSensitivityChanged(arg__1)#
- Parameters:
arg__1 – int
Signal emitted when sensitivity changes to
value
.Notification signal of property
isoSensitivityᅟ
.- manualExposureTime()#
- Return type:
float
Returns the manual exposure time in seconds, or -1 if the camera is using automatic exposure times.
See also
- manualExposureTimeChanged(speed)#
- Parameters:
speed – float
Notification signal of property
manualExposureTimeᅟ
.- manualIsoSensitivity()#
- Return type:
int
See also
Getter of property
manualIsoSensitivityᅟ
.- manualIsoSensitivityChanged(arg__1)#
- Parameters:
arg__1 – int
Notification signal of property
manualIsoSensitivityᅟ
.- maximumExposureTime()#
- Return type:
float
The maximal exposure time in seconds.
- maximumIsoSensitivity()#
- Return type:
int
Returns the maximum ISO sensitivity supported by the camera.
- maximumZoomFactor()#
- Return type:
float
Getter of property
maximumZoomFactorᅟ
.- maximumZoomFactorChanged(arg__1)#
- Parameters:
arg__1 – float
Notification signal of property
maximumZoomFactorᅟ
.- minimumExposureTime()#
- Return type:
float
The minimal exposure time in seconds.
- minimumIsoSensitivity()#
- Return type:
int
Returns the minimum ISO sensitivity supported by the camera.
- minimumZoomFactor()#
- Return type:
float
Getter of property
minimumZoomFactorᅟ
.- minimumZoomFactorChanged(arg__1)#
- Parameters:
arg__1 – float
Notification signal of property
minimumZoomFactorᅟ
.- saturationChanged()#
- setActive(active)#
- Parameters:
active – bool
Turns the camera on if
active
istrue
, or off if it’sfalse
.See also
Setter of property
activeᅟ
.- setAutoExposureTime()#
Use automatically calculated exposure time
- setAutoIsoSensitivity()#
Turn on auto sensitivity
- setCameraDevice(cameraDevice)#
- Parameters:
cameraDevice –
QCameraDevice
Connects the camera object to the physical camera device described by
cameraDevice
. Using a default constructedQCameraDevice
object ascameraDevice
will connect the camera to the system default camera device.See also
Setter of property
cameraDeviceᅟ
.- setCameraFormat(format)#
- Parameters:
format –
QCameraFormat
Tells the camera to use the format described by
format
. This can be used to define a specific resolution and frame rate to be used for recording and image capture.Note
When using the FFMPEG backend on an Android target device if you request YUV420P format, you will receive either a fully planar 4:2:0 YUV420P or a semi-planar NV12/NV21. This depends on the codec implemented by the device OEM.
See also
Setter of property
cameraFormatᅟ
.- setColorTemperature(colorTemperature)#
- Parameters:
colorTemperature – int
Sets manual white balance to
colorTemperature
. This is used whenwhiteBalanceMode()
is set toWhiteBalanceManual
. The units are Kelvin.Setting a color temperature will only have an effect if
WhiteBalanceManual
is supported. In this case, setting a temperature greater 0 will automatically set the white balance mode toWhiteBalanceManual
. Setting the temperature to 0 will reset the white balance mode toWhiteBalanceAuto
.See also
Setter of property
colorTemperatureᅟ
.Setter of property
customFocusPointᅟ
.- setExposureCompensation(ev)#
- Parameters:
ev – float
See also
Setter of property
exposureCompensationᅟ
.- setExposureMode(mode)#
- Parameters:
mode –
ExposureMode
See also
Setter of property
exposureModeᅟ
.Setter of property
flashModeᅟ
.- setFocusDistance(d)#
- Parameters:
d – float
See also
Setter of property
focusDistanceᅟ
.Setter of property
focusModeᅟ
.- setManualExposureTime(seconds)#
- Parameters:
seconds – float
See also
- setManualIsoSensitivity(iso)#
- Parameters:
iso – int
See also
Setter of property
manualIsoSensitivityᅟ
.Setter of property
torchModeᅟ
.- setWhiteBalanceMode(mode)#
- Parameters:
mode –
WhiteBalanceMode
Sets the white balance to
mode
.See also
Setter of property
whiteBalanceModeᅟ
.- setZoomFactor(factor)#
- Parameters:
factor – float
Zooms to a zoom factor
factor
at a rate of 1 factor per second.See also
Setter of property
zoomFactorᅟ
.- start()#
Starts the camera.
Same as
setActive
(true).If the camera can’t be started for some reason, the
errorOccurred()
signal is emitted.- stop()#
Stops the camera. Same as
setActive
(false).Getter of property
supportedFeaturesᅟ
.- supportedFeaturesChanged()#
Notification signal of property
supportedFeaturesᅟ
.- torchMode()#
- Return type:
See also
Getter of property
torchModeᅟ
.- torchModeChanged()#
Notification signal of property
torchModeᅟ
.- whiteBalanceMode()#
- Return type:
See also
Getter of property
whiteBalanceModeᅟ
.- whiteBalanceModeChanged()#
Notification signal of property
whiteBalanceModeᅟ
.- zoomFactor()#
- Return type:
float
See also
Getter of property
zoomFactorᅟ
.- zoomFactorChanged(arg__1)#
- Parameters:
arg__1 – float
Notification signal of property
zoomFactorᅟ
.- zoomTo(zoom, rate)#
- Parameters:
zoom – float
rate – float
Zooms to a zoom factor
factor
usingrate
.The
rate
is specified in powers of two per second. At a rate of 1 it would take 2 seconds to go from a zoom factor of 1 to 4.Note
Using a specific rate is not supported on all cameras. If not supported, zooming will happen as fast as possible.