Stereo Camera

V18 only

Stereo Camera

The pair of 2D cameras, located behind the eyes, provides images in stereo.

Location

https://developers.softbankrobotics.com/sites/default/files/repository/56_html_nao/_images/camera_stereo.png

See the URDF files .

Name
CameraStereo

Specifications

The stereo camera is composed of two identical sensors.

Camera Model OV4689
Type SOC Image Sensor
Imaging Array Resolution 4Mp
Optical format 1/3 inch
Active Pixels (HxV) 1280x720
Sensitivity Pixel size 2µm*2µm
Dynamic range 64.6db@1x gain
Signal/Noise ratio (max) 38.3 dB
Responsivity 1900 mV/Lux-sec
Output Camera output 2560*720@15fps
Data Format YUV422 color space
Shutter type Rolling shutter / frame exposure
View Nominal Field of view 96°HFOV, 60°VFOV
Focus range 40cm ~ infinity
Focus type Fixed focus

Parameters

The dual camera has a list of parameters which can be modified.

Model

Camera Model has the following value:

Parameter ID Name ID Value Description
AL::kOV4689 8 Stereo 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 Remarks
Brightness 0 8 4 kCameraBrightnessID 0
Contrast 0 8 4 kCameraContrastID 1
Saturation 0 8 4 kCameraSaturationID 2
Hue 0 11 0 kCameraHueID 3
Gain 0 1024 NA kCameraGainID 6 Read only if auto exposure enabled
Horizontal Flip 0 1 0 kCameraHFlipID 7
Vertical Flip 0 1 0 kCameraVFlipID 8
Auto Exposition 0 1 1 kCameraAutoExpositionID 11
Auto White Balance 0 1 1 kCameraAutoWhiteBalanceID 12
Exposure 0 1024 NA kCameraExposureID 17 Read only if auto exposure enabled

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 2D camera can have the following values:

Parameter ID Name ID Value Number of layers Number of channels Description
AL::kYuvColorSpace 0 1 1 Buffer only contains the Y (luma component) equivalent to one unsigned char
AL::kyUvColorSpace 1 1 1 Buffer only contains the U (Chrominance component) equivalent to one unsigned char
AL::kyuVColorSpace 2 1 1 Buffer only contains the V (Chrominance component) equivalent to one unsigned char
AL::kRgbColorSpace 3 1 1 Buffer only contains the R (Red component) equivalent to one unsigned char
AL::krGbColorSpace 4 1 1 Buffer only contains the G (Green component) equivalent to one unsigned char
AL::krgBColorSpace 5 1 1 Buffer only contains the B (Blue component) equivalent to one unsigned char
AL::kHsyColorSpace 6 1 1 Buffer only contains the H (Hue component) equivalent to one unsigned char
AL::khSyColorSpace 7 1 1 Buffer only contains the S (Saturation component) equivalent to one unsigned char
AL::khsYColorSpace 8 1 1 Buffer only contains the Y (Brightness component) equivalent to one unsigned char
AL::kYUV422ColorSpace 9 2 2 Native format, 0xY’Y’VVYYUU equivalent to four unsigned char for two pixels . With Y luma for pixel n, Y’ luma for pixel n+1, and U and V are the average chrominance value of both pixels.
AL::kYUVColorSpace 10 3 3 Buffer contains triplet on the format 0xVVUUYY, equivalent to three unsigned char
AL::kRGBColorSpace 11 3 3 Buffer contains triplet on the format 0xBBGGRR, equivalent to three unsigned char
AL::kHSYColorSpace 12 3 3 Buffer contains triplet on the format 0xYYSSHH, equivalent to three unsigned char
AL::kBGRColorSpace 13 3 3 Buffer contains triplet on the format 0xRRGGBB, equivalent to three unsigned char
AL::kYYCbCrColorSpace 14 2 2 TIFF format, four unsigned characters for two pixels .
AL::kH2RGBColorSpace 15 3 3 H from “HSY to RGB” in fake colors.
AL::kHSMixedColorSpace 16 3 3 HS and (H+S)/2.

Supported Format

Format parameter can have the following values:

Resolution ID Name
Resolution
ID Value
FrameRate Value Description
AL::k720px2 13 10 or 15 Image of 2560x720px
AL::kQ720px2 14 10 or 15 Image of 1280x360px
AL::kQQ720px2 15 10 or 15 Image of 640x180px
AL::kQQQ720px2 16 10 or 15 Image of 320x90px
AL::kQQQQ720px2 17 10 or 15 Image of 160x45px

Note

The camera OV4689 can only run internally in 720px2 or Q720px2, otherwise scale down is performed (without binning or linear interpolation).