Pipeline type blaze

Parameters

The camera module on an pipeline of type blaze is called rc_camera and is represented by the Camera page in the desired pipeline in the Web GUI. The user can change the camera parameters there, or directly via the REST-API (REST-API interface) or GigE Vision (GigE Vision 2.0/GenICam image interface).

Parameter overview

This module offers the following run-time parameters:

The rc_camera module’s run-time parameters on a pipeline of type blaze
Name Type Min Max Default Description
exp_auto bool false true true Switching between auto and manual exposure (deprecated, please use exp_control instead)
exp_auto_average_max float64 0.0 1.0 0.5 Maximum average intensity if exp_auto is true
exp_auto_average_min float64 0.0 1.0 0.0 Minimum average intensity if exp_auto is true
exp_auto_mode string - - Normal Auto-exposure mode: [Normal]
exp_control string - - Auto Exposure control mode: [Manual, Auto]
exp_height int32 0 960 0 Height of auto exposure region. 0 for whole image.
exp_max float64 6.6e-05 0.018 0.018 Maximum exposure time in seconds if exp_auto is true
exp_offset_x int32 0 1280 0 First column of auto exposure region
exp_offset_y int32 0 960 0 First row of auto exposure region
exp_value float64 6.6e-05 0.018 0.005 Manual exposure time in seconds if exp_auto is false
exp_width int32 0 1280 0 Width of auto exposure region. 0 for whole image.
fps float64 1.0 25.0 20.0 Frames per second in Hertz
gain_value float64 0.0 18.0 0.0 Manual gain value in decibel if exp_auto is false
wb_auto bool false true true Switching white balance on and off (only for color camera)
wb_ratio_blue float64 0.125 8.0 1.0 Blue to green balance ratio if wb_auto is false (only for color camera)
wb_ratio_red float64 0.125 8.0 1.0 Red to green balance ratio if wb_auto is false (only for color camera)

Description of run-time parameters

Each run-time parameter is represented by a row on the Web GUI’s Camera page. The name in the Web GUI is given in brackets behind the parameter name and the parameters are listed in the order they appear in the Web GUI.

fps (FPS (Hz))

This value is the cameras’ frame rate (fps, frames per second), which determines the upper frequency at which depth images can be computed. This is also the frequency at which the rc_visard NG delivers images via GigE Vision. Reducing this frequency also reduces the network bandwidth required to transmit the images.

Via the REST-API, this parameter can be set as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/parameters?fps=<value>
PUT http://<host>/api/v1/nodes/rc_camera/parameters?fps=<value>

exp_max (Max Exposure)

This value is the maximal exposure time in auto-exposure mode in seconds. The actual exposure time is adjusted automatically so that the images are exposed correctly. If the maximum exposure time is reached, but the images are still underexposed, the rc_visard NG stepwise increases the gain to increase the images’ brightness. Limiting the exposure time is useful for avoiding or reducing motion blur during fast movements. However, higher gain introduces noise into the image. The best trade-off depends on the application.

Via the REST-API, this parameter can be set as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/parameters?exp_max=<value>
PUT http://<host>/api/v1/nodes/rc_camera/parameters?exp_max=<value>

exp_auto_average_max (Max Brightness) and exp_auto_average_min (Min Brightness)

The auto-exposure tries to set the exposure time and gain factor such that the average intensity (i.e. brightness) in the image or exposure region is between a maximum and a minimum. The maximum brightness will be used if there is no saturation, e.g. no over-exposure due to bright surfaces or reflections. In case of saturation, the exposure time and gain factor are reduced, but only down to the minimum brightness.

The maximum brightness has precedence over the minimum brightness parameter. If the minimum brightness is larger than the maximum brightness, the auto-exposure always tries to make the average intensity equal to the maximum brightness.

The current brightness is always shown in the status bar below the images.

Via the REST-API, this parameter can be set as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/parameters?<exp_auto_average_max|exp_auto_average_min>=<value>
PUT http://<host>/api/v1/nodes/rc_camera/parameters?<exp_auto_average_max|exp_auto_average_min>=<value>

exp_offset_x, exp_offset_y, exp_width, exp_height (Exposure Region)

These values define a rectangular region in the left rectified image for limiting the area used for computing the auto exposure. The exposure time and gain factor of both images are chosen to optimally expose the defined region. This can lead to over- or underexposure of image parts outside the defined region. If either the width or height is 0, then the whole left and right images are considered by the auto exposure function. This is the default.

The region is visualized in the Web GUI by a rectangle in the left rectified image. It can be defined using the sliders or by selecting it in the image after pressing the button Select Region in Image.

Via the REST-API, this parameter can be set as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/parameters?<exp_offset_x|exp_offset_y|exp_width|exp_height>=<value>
PUT http://<host>/api/v1/nodes/rc_camera/parameters?<exp_offset_x|exp_offset_y|exp_width|exp_height>=<value>

exp_value (Exposure)

This value is the exposure time in manual exposure mode in seconds. This exposure time is kept constant even if the images are underexposed.

Via the REST-API, this parameter can be set as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/parameters?exp_value=<value>
PUT http://<host>/api/v1/nodes/rc_camera/parameters?exp_value=<value>

gain_value (Gain (dB))

This value is the gain factor in decibel that can be set in manual exposure mode. Higher gain factors reduce the required exposure time but introduce noise.

Via the REST-API, this parameter can be set as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/parameters?gain_value=<value>
PUT http://<host>/api/v1/nodes/rc_camera/parameters?gain_value=<value>

wb_auto (White Balance Auto or Manual)

This value can be set to true for automatic white balancing or false for manually setting the ratio between the colors using wb_ratio_red and wb_ratio_blue. The last automatically determined ratios are set into wb_ratio_red and wb_ratio_blue when switching automatic white balancing off. White balancing is without function for monochrome cameras and will not be displayed in the Web GUI in this case.

Via the REST-API, this parameter can be set as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/parameters?wb_auto=<value>
PUT http://<host>/api/v1/nodes/rc_camera/parameters?wb_auto=<value>

wb_ratio_blue and wb_ratio_red (Blue | Green and Red | Green)

These values are used to set blue to green and red to green ratios for manual white balance. White balancing is without function for monochrome cameras and will not be displayed in the Web GUI in this case.

Via the REST-API, this parameter can be set as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/parameters?<wb_ratio_blue|wb_ratio_red>=<value>
PUT http://<host>/api/v1/nodes/rc_camera/parameters?<wb_ratio_blue|wb_ratio_red>=<value>

These parameters are also available over the GenICam interface with slightly different names and partly with different units or data types (see GigE Vision 2.0/GenICam image interface).

Status values

The rc_camera module reports the following status values on a pipeline of type blaze.

The rc_camera module’s status values on a pipeline of type blaze
Name Description
baseline Stereo baseline \(t\) in meters
color 0 for monochrome cameras, 1 for color cameras
exp Current exposure time in seconds. This value is shown below the image preview in the Web GUI as Exposure (ms).
focal Focal length factor normalized to an image width of 1
fps Current frame rate of the camera images in Hertz. This value is shown in the Web GUI below the image preview as FPS (Hz).
gain Current gain factor in decibel. This value is shown in the Web GUI below the image preview as Gain (dB).
height Height of the camera image in pixels. This value is shown in the Web GUI below the image preview as the second part of Resolution (px).
width Width of the camera image in pixels. This value is shown in the Web GUI below the image preview as the first part of Resolution (px).

Services

The rc_camera module offers the following services on a pipeline of type blaze.

reset_defaults

Restores and applies the default values for this module’s parameters (“factory reset”).

Details

This service can be called as follows.

PUT http://<host>/api/v2/pipelines/<0,1,2,3>/nodes/rc_camera/services/reset_defaults
PUT http://<host>/api/v1/nodes/rc_camera/services/reset_defaults
This service has no arguments.

The definition for the response with corresponding datatypes is:

{
  "name": "reset_defaults",
  "response": {
    "return_code": {
      "message": "string",
      "value": "int16"
    }
  }
}