87 lines
3.1 KiB
Python
87 lines
3.1 KiB
Python
import json
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from collections import deque
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import cv2
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class BallFinder(object):
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def __init__(self, hsv_lower, hsv_upper, min_radius, viz=False):
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self.hsv_lower = hsv_lower
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self.hsv_upper = hsv_upper
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self.min_radius = min_radius
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self.history = deque(maxlen=64)
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self.viz = viz
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if self.viz:
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cv2.namedWindow('ball_mask')
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cv2.namedWindow('Frame')
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def find_colored_ball(self, frame):
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hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
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# construct a mask for the color, then perform a series of
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# dilations and erosions to remove any small blobs left in the mask
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mask = cv2.inRange(hsv, self.hsv_lower, self.hsv_upper)
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mask = cv2.erode(mask, None, iterations=2)
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mask = cv2.dilate(mask, None, iterations=2)
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if self.viz:
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cv2.imshow('ball_mask', mask)
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# find contours in the mask and initialize the current
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# (x, y) center of the ball
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cnts = cv2.findContours(mask.copy(), cv2.RETR_EXTERNAL,
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cv2.CHAIN_APPROX_SIMPLE)[-2]
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# only proceed if at least one contour was found
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if len(cnts) == 0:
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self.history.appendleft(None)
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return None
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# find the largest contour in the mask, then use it to compute
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# the minimum enclosing circle and centroid
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c = max(cnts, key=cv2.contourArea)
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((x, y), radius) = cv2.minEnclosingCircle(c)
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if radius < self.min_radius:
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self.history.appendleft(None)
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return None
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M = cv2.moments(c)
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center = (int(M["m10"] / M["m00"]),int(M["m01"] // M["m00"]))
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self.history.appendleft((center, int(radius)))
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return center, int(radius)
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def visualize(self, frame):
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if not self.viz:
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raise ValueError(
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'Visualization needs to be enabled when initializing'
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)
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frame = frame.copy()
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if self.history[0] is not None:
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center, radius = self.history[0]
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cv2.circle(frame, center, radius, (255, 255, 0), 1)
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cv2.circle(frame, center, 5, (0, 255, 0), -1)
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# loop over the set of tracked points
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for i in range(1, len(self.history)):
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# if either of the tracked points are None, ignore them
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if self.history[i - 1] is None or self.history[i] is None:
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continue
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# otherwise, compute the thickness of the line and
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# draw the connecting lines
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center_now = self.history[0][0]
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center_prev = self.history[1][0]
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thickness = int((64 / (i + 1))**0.5 * 2.5)
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cv2.line(frame, center_now, center_prev, (0, 255, 0), thickness)
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# show the frame to screen
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cv2.imshow("Frame", frame)
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return cv2.waitKey(1)
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def load_hsv_config(self, filename):
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with open(filename) as f:
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hsv = json.load(f)
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self.hsv_lower = tuple(map(hsv.get, ('low_h', 'low_s', 'low_v')))
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self.hsv_upper = tuple(map(hsv.get, ('high_h', 'high_s', 'high_v')))
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