Configuring a Video Capture Device
This section contains a small example program showing how to configure a video capture device through the ic4::PropertyMap interface.
The article Accessing Device Properties explains the capabilities of the property classes in detail.
Open a Device
For demonstration purposes, we open the first available video capture device:
// Create a grabber object
ic4::Grabber grabber;
// Open the first available video capture device
auto info = ic4::DeviceEnum::enumDevices().front();
grabber.deviceOpen(info);static std::vector< DeviceInfo > enumDevices(Error &err=Error::Default())
Get a list of the devices currently attached to the system.
Definition DeviceEnum.h:446
Represents an opened video capture device, allowing device configuration and stream setup.
Definition Grabber.h:82
bool deviceOpen(const DeviceInfo &dev, Error &err=Error::Default())
Opens the video capture device specified by the passed device information object.
Definition Grabber.h:147
Configure the Resolution
Next, we configure the device to output Mono8 data with a ROI of 640x480:
// Configure the device to output images in the Mono8 pixel format
grabber.devicePropertyMap().setValue(ic4::PropId::PixelFormat, ic4::PixelFormat::Mono8);
// Set the resolution to 640x480
grabber.devicePropertyMap().setValue(ic4::PropId::Width, 640);
grabber.devicePropertyMap().setValue(ic4::PropId::Height, 480);PropertyMap devicePropertyMap(Error &err=Error::Default()) const
Returns the property map for the currently opened video capture device.
Definition Grabber.h:561
bool setValue(const char *integer_name, int64_t value, Error &err=Error::Default())
Set the value of a property with a known name to the passed integer value.
Definition Properties.h:1982
constexpr PropIdEnumeration PixelFormat
Format of the pixels provided by the device.
Definition PropertyConstants.h:870
constexpr PropIdInteger Height
Height of the image provided by the device (in pixels).
Definition PropertyConstants.h:700
constexpr PropIdInteger Width
Width of the image provided by the device (in pixels).
Definition PropertyConstants.h:1100
Define ROI Origin
Then, the origin of the ROI is moved to the top left corner of the sensor:
// Set the origin of the ROI to the top-left corner of the sensor
grabber.devicePropertyMap().setValue(ic4::PropId::OffsetAutoCenter, "Off");
grabber.devicePropertyMap().setValue(ic4::PropId::OffsetX, 0);
grabber.devicePropertyMap().setValue(ic4::PropId::OffsetY, 0);constexpr PropIdInteger OffsetX
Horizontal offset from the origin to the region of interest (in pixels).
Definition PropertyConstants.h:855
constexpr PropIdEnumeration OffsetAutoCenter
Automatically adjust the values of OffsetX and OffsetY to select the center region of the sensor.
Definition PropertyConstants.h:850
constexpr PropIdInteger OffsetY
Vertical offset from the origin to the region of interest (in pixels).
Definition PropertyConstants.h:860
Set an Exposure Time
Finally, we configure the device to a fixed exposure time of 5ms and enable automatic gain control:
// Configure the exposure time to 5ms (5000�s)
grabber.devicePropertyMap().setValue(ic4::PropId::ExposureAuto, "Off");
grabber.devicePropertyMap().setValue(ic4::PropId::ExposureTime, 5000.0);
// Enable GainAuto
grabber.devicePropertyMap().setValue(ic4::PropId::GainAuto, "Continuous");constexpr PropIdEnumeration ExposureAuto
Sets the automatic exposure mode when ExposureMode is Timed.
Definition PropertyConstants.h:545
constexpr PropIdFloat ExposureTime
Sets the Exposure time when ExposureMode is Timed and ExposureAuto is Off.
Definition PropertyConstants.h:580
constexpr PropIdEnumeration GainAuto
Sets the automatic gain control mode.
Definition PropertyConstants.h:650
