Conference Room Laser Pointer System Preliminary Design Report Anna Goncharova Brent Hoover Alex Mendes

Presentation Outline Project Concept Last year’s progress Image processing component – Approach: trial and error – Use of OpenCV – Possible algorithms Hardware component – Webcam – Relay to turn secondary laser on and off – Hardware arrangement

Project Concept “In large conference room presentations when the slides are shown on multiple screens, there is no good solution for pointing a laser at one screen and having it shown on the other(s). This project will use camera(s) to monitor large conference projection screens and look for a laser pointer. When a laser is determined, another laser will be turned on to the other screen and project the pointer to the same spot on the screen.”

Last Year’s Progress Last year's team completed the mounted system that activates the secondary laser that points to the second projection screen However, they were not able to make the secondary laser turn on and off Also, they made the user use a touch-screen monitor instead of using a webcam to locate the primary laser

Last Year Touch screen used instead

This Year Webcam Mounted system Computer

Image Processing Approach Try different algorithms and use trial and error to determine the best one to use OpenCV website has many C and C++ algorithms available for use Possible approaches include: – Hue Saturation Value Conversion – Brightness Selection – Keying out (background subtraction)

We Will Try Multiple Techniques for Pinpointing the Laser Hue-Saturation-Value – We first convert from RGB pixels to HSV pixels – To find the laser, we search for the desired green hue – We can use some premade OpenCV functions Brightness Selection (alternative to hue selection) – We place the laser pointer at regions whose brightness level resembles that of the laser. – HSV conversion must be applied before this technique Keying Out – We assign each pixel a ‘green-ness’ value – Then, we erase the pixels that are the least green Regional Intensity Functions (used for preprocessing) – We apply a function to a pixel which uses nearby pixels as input parameters

Hardware Components WebCam Mounted, to observe primary laser COM port Host Computer Laser Coords (x,y) Laser Tracking Program Implements OpenCV Manages host PC I/O External DC Power 3.3V Replicated Laser 5V 2 Servo Motors Positioning pitch and yaw COM Port (Relay)

Servo Motor Control Operates in 3 Dimensions, with 2 Degrees of Freedom – 1 Motor controls laser pitch (up/down) – 2 nd Motor controls laser yaw (left/right) Laser is mounted on top of servos PC program sends out Pulse-Width-Modulated COM Port signal to relay – Relay amplifies signal to 5V to power servos – When no source laser detected, replication laser is turned off

Hardware Arrangement Computer is in the center of arrangement where connection cables are at appropriate distances (USB/Serial Port/etc.) Primary laser pointer is in the hand of the presenter Webcam is mounted to view complete primary presentation screen Replicating system is assembled in a fixed position Secondary laser is on top of the servo motors which are fixed to a box

Conclusion This project has two distinct components – Image processing to detect primary laser – Hardware/electronics to activate secondary laser and direct it to appropriate position on presentation screen The finished project will be available for immediate use for multi-screen conference presentations