樹莓派-配合opencv實作的攝像頭跟随

這是在顔色識别的基礎上，通過顔色的位置的判斷，進而控制舵機的旋轉

基本原理就是這樣吧。。。。。

from __future__ import division
import time
import Adafruit_PCA9685
import cv2
import numpy as np
i = 3
pwm = Adafruit_PCA9685.PCA9685()
servo_min = 150
def set_servo_pulse(channel,pulse):
    pulse_length = 1000000
    pulse_length //= 60
    pulse_length //= 4096
    pulse *= 1000
    pulse //= pulse_length
    pwm.set_pwm(channel,0,pulse)
def set_servo_angle(channel,angle):
    angle=4096*((angle*11)+500)/20000
    pwm.set_pwm(channel,0,int(angle))
pwm.set_pwm_freq(50)
blue_lower = np.array([100,43,46])
blue_upper = np.array([124,255,255])
cap = cv2.VideoCapture(0)
cap.set(3,320)
cap.set(4,240)
def newGetDirection(x):   #舵機角度的控制
    global i
    if i < 2:
        i = 2
    elif i > 180:
        i = 180
    if 0 < x < 130:
        i = i +5
        set_servo_angle(1,i)
    elif 130 <= x < 220:
        pass
    else:
        i = i -5
        set_servo_angle(1,i)
while 1:
    ret,frame = cap.read()
    frame = cv2.GaussianBlur(frame,(5,5),0)
    hsv = cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)
    mask = cv2.inRange(hsv,blue_lower,blue_upper)

    mask = cv2.erode(mask,None,iterations=2)
    mask = cv2.GaussianBlur(mask,(3,3),0)
    res = cv2.bitwise_and(frame,frame,mask=mask)
    cnts = cv2.findContours(mask.copy(),cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)[-2]
    if len(cnts) > 0:
        cnt = max(cnts,key=cv2.contourArea)
        (x,y),radius = cv2.minEnclosingCircle(cnt)
        cv2.circle(frame,(int(x),int(y)),int(radius),(255,0,255),2)
        print(int(x))
        newGetDirection(x)
    else:
        pass
    cv2.imshow("frame",frame)
    cv2.imshow("mask",mask)
    cv2.imshow("res",res)
    if cv2.waitKey(5) & 0xFF == 27:
        break
def doSomething(x):
    set_servo_angle(1,x)

cap.release()
cv2.destroyAllWindows()