Video camera

../../_images/video_camera.png

A camera capturing RGBA image

This sensor emulates a single video camera. It generates a series of RGBA images. Images are encoded as binary char arrays, with 4 bytes per pixel.

Camera calibration matrix

The camera configuration parameters implicitly define a geometric camera in blender units. Knowing that the cam_focal attribute is a value that represents the distance in Blender unit at which the largest image dimension is 32.0 Blender units, the camera intrinsic calibration matrix is defined as

alpha_u 0 u_0
0 alpha_v v_0
0 0 1

where:

  • alpha_u == alpha_v = cam_width . cam_focal / 32 (we suppose here that cam_width > cam_height. If not, then use cam_height in the formula)
  • u_0 = cam_width / 2
  • v_0 = cam_height / 2

See also Generic Camera for generic informations about Morse cameras.

Configuration parameters for Video camera

You can set these properties in your scripts with <component>.properties(<property1>=..., <property2>=...).

  • cam_width (default: 256)
    (no documentation available yet)
  • cam_height (default: 256)
    (no documentation available yet)
  • cam_focal (default: 25.0)
    (no documentation available yet)
  • cam_fov (default: None)
    (no documentation available yet)
  • cam_near (default: 0.1)
    (no documentation available yet)
  • cam_far (default: 100.0)
    (no documentation available yet)
  • Vertical_Flip (default: True)
    (no documentation available yet)
  • retrieve_depth (default: False)
    (no documentation available yet)
  • retrieve_zbuffer (default: False)
    (no documentation available yet)

Data fields

This sensor exports these datafields at each simulation step:

  • timestamp (float, initial value: 0.0)
    number of seconds in simulated time
  • image (buffer, initial value: none)
    The data captured by the camera, stored as a Python Buffer class object. The data is of size (cam_width * cam_height * 4) bytes. The image is stored as RGBA.
  • intrinsic_matrix (mat3<float>, initial value: none)
    The intrinsic calibration matrix, stored as a 3x3 row major Matrix.

Interface support:

Services for Video camera

  • capture(n) (non blocking)

    Capture n images

    • Parameters
      • n: the number of images to take. A negative number means take image indefinitely
  • get_configurations() (blocking)

    Returns the configurations of a component (parsed from the properties).

    • Return value

      a dictionary of the current component’s configurations

  • get_local_data() (blocking)

    Returns the current data stored in the sensor.

    • Return value

      a dictionary of the current sensor’s data

  • get_properties() (blocking)

    Returns the properties of a component.

    • Return value

      a dictionary of the current component’s properties

  • set_property(prop_name, prop_val) (blocking)

    Modify one property on a component

    • Parameters

      • prop_name: the name of the property to modify (as shown the documentation)
      • prop_val: the new value of the property. Note that there is no checking about the type of the value so be careful

    • Return value

      nothing

Examples

The following examples show how to use this component in a Builder script:

from morse.builder import *

# adds a default robot (the MORSE mascott!)
robot = Morsy()

# creates a new instance of the sensor
videocamera = VideoCamera()

# place your component at the correct location
videocamera.translate(<x>, <y>, <z>)
videocamera.rotate(<rx>, <ry>, <rz>)

robot.append(videocamera)

# define one or several communication interface, like 'socket'
videocamera.add_interface(<interface>)

env = Environment('empty')

Other sources of examples

(This page has been auto-generated from MORSE module morse.sensors.video_camera.)