Detecting the Robot

The above image shows the robot under the green triangle. To detect the triangle we use the RGBFilter module set to filter on green.

We can see that the triangle is there but it has some small holes in it. The Fill module with a parameter of zero will fill in any remaining holes.

To smooth out the triangle border and remove some of the additional noise we add the Erode module to produce a cleaner image. We also add in the Blob Filter and set it to eliminate all but the largest blob just in case some other green artifact remains after the erosion. This also provides us with a COG_X and COG_Y array with a single entry that contains the X, Y center of the triangle and is used to determine where the robot's position is.

That completes the green triangle (robot) extraction. Now we need to find out which direction the triangle is pointing so that we know which direction to turn the robot.