« Previous - Version 188/265 (diff) - Next » - Current version
Kwabena Agyeman, 05/11/2012 12:01 am


Wiki

Quick Links

Cool Videos

  • CMUcam4 Test - By Lextronics. It's in French - But shows functionality.
  • CMUcam4 Pan/Tilt Test - By Parallax. This is a development video of the CMUcam4. The red version is a prototype.

Cool Projects

Where can I buy a CMUcam4?

Typical Uses

The CMUcam4 can be used to track colors or collect basic image statistics. The best performance can be achieved when there are highly contrasting and intense colors. For instance, it can easily track a red ball on a white background, but it would be hard to differentiate between different shades of brown in changing light. Tracking colorful objects can be used to localize landmarks, follow lines, or chase moving beacons. Using color statistics, it is possible for the CMUcam4 to monitor a scene, detect a specific color, or do primitive motion detection. If the CMUcam4 detects a drastic color change, then chances are something in the scene changed. Using “line mode”, the CMUcam4 can generate low resolution binary images of colorful objects. This can be used to do more sophisticated image processing that includes line following with branch detection, or even simple shape recognition. These more advanced operations require custom algorithms to post process the binary images sent from the CMUcam4. As is the case with a normal digital camera, this type of processing might require a computer or at least a fast microcontroller.

Typical Configuration

The most common configuration for the CMUcam4 is to have it communicate to a master processor via a standard TTL serial port. This “master processor” could be a computer (through USB or RS232), Arduino, Basic Stamp, PIC, or similar microcontroller. The CMUcam4 is small enough to add simple vision to embedded systems that can not afford the size or power of a standard computer based vision system. Its communication protocol is designed to accommodate even the slowest of processors. The CMUcam4 supports various baud rates to accommodate slower processors. For even slower processors, the CMUcam4 can operate in “poll mode”. In this mode, the host processor can ask the CMUcam4 for just a single packet of data. This gives slower processors the ability to more easily stay synchronized with the data. It is also possible to add a delay between individual serial data characters using the “delay mode” command. Due to communication delays, both poll mode and delay mode will lower the total number of frames that can be processed in one second.

CMUcam4_A.JPG - Picture A (49.2 kB) Kwabena Agyeman, 03/14/2012 10:44 pm

CMUcam4_B.JPG - Picture B (26.8 kB) Kwabena Agyeman, 03/14/2012 10:44 pm