Simple Gear Detection

[amstrudy]

Here is Team 900's very simple gear detection based off of color and area.

# basic gear detection from HSV
# 1/14/17
# Team 900 Zebracorns
# Author: Anja S

import cv2
import numpy as np

cap = cv2.VideoCapture(1)

kernel = np.ones((5,5),np.uint8)

while(1):

	# Take each frame
	_, frame = cap.read()

	hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)

	# Threshold the HSV image
	lower = np.array([20, 55, 124])
	upper = np.array([48, 255, 247])

	mask = cv2.inRange(hsv, lower, upper)

	opening = cv2.morphologyEx(mask, cv2.MORPH_OPEN, kernel)
	closing = cv2.morphologyEx(opening, cv2.MORPH_CLOSE, kernel)

	# Contours
	contours = cv2.findContours(closing,cv2.cv.CV_RETR_TREE,cv2.cv.CV_CHAIN_APPROX_SIMPLE)[0]

	# Remove contours that don't fit area and HSV constraints

	gear_contour = []

	for c in contours:

		moments = cv2.moments(c)
		area = cv2.contourArea(c)

		if area < 3000: continue

		perim = cv2.arcLength(c, True)
		approx = cv2.approxPolyDP(c, 0.00005*perim, True)

		if len(approx) > 20:
			gear_contour.append(approx)

		for x in range(0, len(gear_contour)):

			minX = 10000
			minY = 10000
			maxX = 0
			maxY = 0
			cx = (minX + maxX)//2
			cy = (minY + maxY)//2

			# draw box around gear contour

			for y in range(0, len(gear_contour[x])):

				if gear_contour[x][y][0][0] < minX:
					minX = gear_contour[x][y][0][0]
				if gear_contour[x][y][0][1] < minY:
					minY = gear_contour[x][y][0][1]
				if gear_contour[x][y][0][0] > maxX:
					maxX = gear_contour[x][y][0][0]
				if gear_contour[x][y][0][1] > maxY:
					maxY = gear_contour[x][y][0][1]
			if gear_contour:

				cv2.drawContours(frame, gear_contour, -1, (255, 0, 0),3)
				cv2.rectangle(frame,(minX, minY),(maxX, maxY),(255,255,0),3)


	cv2.imshow('frame',frame)

	k = cv2.waitKey(5) & 0xFF
	if k == 27:
		break

cv2.destroyAllWindows()

[Ari423]

I always love to see what you guys do with vision processing. Just wondering since it relies on area about how far away can the gear be before it's no longer big enough to be recognized? Also how close?

[DonRotolo]

Very nice, but can you expound on why one would wish to detect a gear?

[dirtbikerxz]

Originally Posted by DonRotolo

Very nice, but can you expound on why one would wish to detect a gear?

For catching gears that the human players throw across the field of course.

[Billfred]

Originally Posted by DonRotolo

Very nice, but can you expound on why one would wish to detect a gear?

So you can cheesecake an autonomous routine onto your partner to shimmy their preload gear out of their possession, and onto the floor for your 2-to-3-gear auto?