3D Sensor¶
The robot head is composed of three cameras:
- two 2D Cameras, and
- one 3D Sensor.
Camera indexes¶
The camera indexes are:
| Parameter ID Name | ID Value | Description |
|---|---|---|
| AL::kTopCamera | 0 | camera on the top. |
| AL::kBottomCamera | 1 | camera on the bottom. |
| AL::kDepthCamera | 2 | 3D camera in the eyes. |
3D Sensor¶
One 3D camera is located in the forehead. It provides image resolution up to 320x240 at 20 frames per second.
Location¶
One ASUS Xtion 3D sensor is located behind the eyes.
See the URDF files.
| Name | VFOV | HFOV |
|---|---|---|
| CameraDepth_sensor | 45.00° | 58.00° |
Specifications¶
| Camera | Model | ASUS XTION |
| Type | SOC Image Sensor | |
| Imaging Array | Optical format | 1/2 inch (5:4) |
| Active Pixels (HxV) | 1280x1024 | |
| Sensitivity | Pixel size | 5.2µm*5.2µm |
| Dynamic range | 68.2db |
|
| Signal/Noise ratio (max) | 45dB | |
| Responsivity | 2.1 V/Lux-sec | |
| Output | Camera output | 320*240@20fps |
| Data Format | Depth color space (mm) | |
| Shutter type | Electronic Rolling shutter (ERS) | |
| View | Field of view | 70.0°DFOV (58.0°HFOV,45.0°VFOV) |
| Focus range | 40cm ~ 8m | |
| Focus type | Fixed focus |
Parameters¶
The camera has a list of parameters which can be modified.
Model¶
Camera Model has the following value:
| Parameter ID Name | ID Value | Description |
|---|---|---|
| AL::kXTION | 4 | 3D Camera |
Supported parameters¶
Software parameters¶
| Parameter | Min value | Max value | Default value | Camera ID name | ID value |
|---|---|---|---|---|---|
| Keep Alive | 0 | 1 | 0 | kCameraKeepAliveID | 35 |
Hardware parameters¶
| Parameter | Min value | Max value | Default Value | Camera ID name | ID value |
|---|---|---|---|---|---|
| Resolution | kQQVGA | kVGA | kQVGA | kCameraResolutionID | 14 |
| Frames Per Second | 1 | 20 | 1 | kCameraFrameRateID | 15 |
Supported colorspaces¶
A color space is a model describing the way to represent color as an ordered list of numbers. For example you can represent the color of each pixel of your screen as a list of three elements R, G and B. Which are respectively the value of Red, Green, and Blue usually stored in an byte (range from 0 to 255).
Setting the color space allows you to set the image buffer encoding in
AL::ALImage.
Color space parameter for 3D camera can have the following values:
| Parameter ID Name | ID Value |
|
Number of channels | Description |
|---|---|---|---|---|
| AL::kYuvColorSpace | 0 | 1 | 1 | Contains the depth image clamped from 400m to 3.68m scaled in range [0,255], equivalent to one unsigned char |
| AL::kRGBColorSpace | 11 | 3 | 3 | Contains the depth image in false-color (RGB) equivalent to three unsigned char (debug purpose) |
| AL::kDepthColorSpace | 17 | 2 | 1 | Contains the distance in mm from the image plan corrected, equivalent to one unsigned short |
| AL::kXYZColorSpace | 19 | 12 | 3 | Contains the position in meter of the voxel in the camera frame, equivalent to three float |
| AL::kDistanceColorSpace | 21 | 2 | 1 | Contains the distance from the camera in mm, equivalent to one unsigned short |
| AL::kRawDepthColorSpace | 23 | 2 | 1 | Contains the raw distance in mm from the image plan without correction, equivalent to one unsigned short |
Supported resolutions¶
Resolution parameter can have the following values:
| Parameter ID Name | ID Value | Description |
|---|---|---|
| AL::kQQQQVGA | 8 | Image of 40*30px |
| AL::kQQQVGA | 7 | Image of 80*60px |
| AL::kQQVGA | 0 | Image of 160*120px |
| AL::kQVGA | 1 | Image of 320*240px |
Supported framerates¶
Here a list of supported frame rates according to resolution set.
| Resolution | Supported Frame rate |
|---|---|
| AL::kQQQQVGA | from 1 to 20 fps |
| AL::kQQQVGA | from 1 to 20 fps |
| AL::kQQVGA | from 1 to 20 fps |
| AL::kQVGA | from 1 to 20 fps |
