To choose the right stereo cameras for your application, it helps to understand the characteristics of our Apparen stereo vision systems. This page is a summary of the information you will need to make an informed choice of a stereo device, with links to additional information. The first section helps you select by features, the second section by applications, and the third by baseline and optics.
| Model | Max Resolution Max Rate |
Baseline (cm) |
Stereo Processing | Shutter | Factory Calibrate |
Color or Mono |
Lenses |
|---|---|---|---|---|---|---|---|
| STOC | 640x480 30 Hz @ 640 x 480 |
6 9 15 30 |
On camera | Global | Yes | Yes/Yes |
Miniature 12 mm dia. |
| STH-DCSG | 640x480 30 Hz @ 640x480 60 Hz @ 320x240 |
6 9 15 30 |
On PC | Global | Yes | Yes/Yes |
For 6, 15, and 30 cm: Miniature 12 mm dia. 2.5, 3.0, 4.3, or 5.6 mm For 9cm: 1/2" format C-mount, locking 3.5, 4.5, or 6.0 mm |
|
STH-DCSG-VAR STH-DCSG-VARX |
640x480 |
5-20 18-60 |
On PC | Global | No | Yes/Yes | 1/2" format C-mount, locking 3.5, 4.5, or 6.0 mm |
|
STH-MDCS STH-MDCS-VAR STH-MDCS-VARX |
1280x960 7.5 Hz @ 1280x960 30 Hz @ 640x480 |
9 9-20 (color) 5-20 (mono) 18-60 |
On PC | Rolling | No |
Yes/Yes |
1/2" format C-mount, locking 3.5, 4.5, or 6.0 mm |
*The STOC-9CM is also available with the same C-mount locking lenses as the VAR models.
| Product | Baseline | Object Distance | Application |
|---|---|---|---|
| STOC-6CM STH-DCSG-6CM STH-DCSG-VAR STH-MDCS-VAR |
6 cm 5-20 cm |
Close Work |
Head Tracking |
| STOC-9CM STH-DCSG-9CM STH-MDCS-9CM STOC-15CM STH-DCSG-15CM STH-DCSG-VAR STH-MDCS-VAR |
9 cm 15 cm 5-20 cm |
Moderate Distance (15-20 m) | People Tracking Obstacle Detection and Avoidance |
| STOC-30CM STH-DCSG-30CM STH-DCSG-VARX STH-MDCS-VARX |
30 cm |
Long Distance | Outdoor Scene Reconstruction Vehicle Obstacle Detection |
The baseline is the distance between the two cameras. Smaller baselines work well for close objects, larger baselines give better depth precision for far-away objects.
The baseline and the lens field of view interact to determine the basic characteristics of the stereo device. You can use the Stereo Worksheet to help determine the best baseline and lenses for your application.
Videre Design makes both fixed and variable baseline devices. The fixed baseline devices are recommended for most applications, since they are pre-calibrated and maintain their calibration. Calibration compensates for any lens distortion and mechanical misalignment of the cameras. All Videre Design products can also be easily calibrated in the field, should it be needed.
Variable baseline devices allow the most flexibility in prototyping. The standard device is adjustable from 5 - 20 cm, the extended range device from 18 - 60 cm. The STOC is not available as a variable-baseline device.
More information: Stereo Worksheet
Computing 3D stereo results is computationally expensive. Videre Design
uses SRI International's best-of-class algorithms for efficient
computation. The computations can be performed on a PC, or on-camera,
with Videre Design's Stereo-on-a-Chip (STOC) camera. The STOC uses a
fraction of the power of a PC, yet produces the same result. Since the
STOC frees up the PC for other work, it is recommended where realtime
performance and/or low power are important.
More information:
Videre Design's cameras use CMOS imagers, with a resolution of 1280 x 960 (STH-MDCS devices) or 640 x 480 (STH-DCSG and STOC devices). For realtime applications and higher frame rates, the smaller resolution is appropriate. For applications that need higher resolution, the megapixel devices are better.
The DCSG / STOC devices have a global shutter, which means that all pixels are exposed at exactly the same time. For capturing rapid motion, or when the stereo device itself is moving, global shutter is required. The MDCS devices have a rolling shutter, which means that each line of the image is exposed at a slightly different time. These devices are good when the cameras are stationary.
More information: Global Shutter Video
If your application does not need color, then monochrome devices are best, because they have better effective resolution than the corresponding color device. Videre Design cameras are also sensitive in the near infrared band, for specialized applications.
More information: Monochrome, Color and Infrared