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Kwabena Agyeman, 03/09/2012 10:39 pm


Frequently Asked Questions

What is unique about CMUcam4?

Traditionally fast computers are needed to capture and process camera images. It is also necessary to write the software to perform this processing. Because of this it is difficult to use vision as a sensor in simple systems.

The CMUcam4 vision system uses a fast low cost microcontroller to handle all of the high speed processing of the camera data and contains software to perform simple vision tasks. Because the user can choose to output only low bandwidth high level information from the vision system, like the red object is at position X-Y, it is possible for a simple processor like a Arduino or BASIC Stamp 2 microcontroller to read this data and direct a small robot in tasks like chasing a colored ball. The CMUcam4 vision system makes it possible to ignore the complexity of camera interfacing and use vision just like any other sensor (i.e. sonar) often used in robotic systems.

Additionally, with new TV output functionality, you can see what the CMUcam4 sees on the TV to verify that it is working!

What is CMUcam4's frame rate?

The frame rate is 10 frames per second. This means CMUcam4 can tell you the position of an object 10 times per second. Using the serial software protocol you can slow this down if desired.

What baud rates does the CMUcam4 support?

The CMUcam4 can communicate at any baud rate using the serial software protocol. The default power on baud rate is 19,200 bits per second.

How do I upgrade my CMUcam4 firmware?

Please see the firmware wiki page.

Does CMUcam4 work outside?

The CMUcam4 works outside but not in direct sunshine. It is possible to add an external filter to improve outdoor operation.

Can I write custom code for CMUcam4?

Please see the firmware wiki page.

How much power does CMUcam4 consume?

The complete system consumes about 150 milliamperes.

What is the camera's field of view?

About a 25 degree field of view, which is relatively narrow.

What processor does CMUcam4 use?

Please see the firmware wiki page.

What CMOS camera does CMUcam4 use?

Please see the firmware wiki page.

Does CMUcam4 work with other CMOS cameras?

No. Currently the hardware and software system have been designed to work specifically with the OmniVision OV9665 CMOS camera. The system would need to be completely redesigned to work with another camera.

Is there some place I can find answers to additional questions I have?

Yes. Please visit the forums here.

Where can I find out more about computer vision in general?

The CMUcam4 performs the simple computer vision task it was designed to perform in a small, inexpensive package. However, the general computer vision problem of trying to recognize arbitrary objects under arbitrary conditions is still a very active research topic and very far from being anywhere near a solved problem.

If you want to learn more about computer vision, you might want to try these links:

The On-Line Compendium of Computer Vision
The Computer Vision Home Page at CMU