Tutorial

99
Set target color, HSV color space
'''
colorUpper = np.array([44, 255, 255])
colorLower = np.array([24, 100, 100])
font = cv2.FONT_HERSHEY_SIMPLEX
class Camera(BaseCamera):
video_source = 0
def __init__(self):
if os.environ.get('OPENCV_CAMERA_SOURCE'):
Camera.set_video_source(int(os.environ['OPENCV_CAMERA_SOURCE']))
super(Camera, self).__init__()
@staticmethod
def set_video_source(source):
Camera.video_source = source
@staticmethod
def frames():
camera = cv2.VideoCapture(Camera.video_source)
if not camera.isOpened():
raise RuntimeError('Could not start camera.')
while True:
# read current frame
img = camera.read() #Get the picture captured by the camera
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV) #Convert captured images to HSV color space
mask = cv2.inRange(hsv, colorLower, colorUpper) #Traverse the colors in the target color range in the HSV
color space, and turn these color blocks into masks
mask = cv2.erode(mask, None, iterations=2) #Corrosion of small pieces of mask (noise) in the picture
becomes small (small pieces of color or noise disappear)
mask = cv2.dilate(mask, None, iterations=2) #Inflate, and resize the large mask that was reduced in the
previous step to its original size
cnts = cv2.findContours(mask.copy(), cv2.RETR_EXTERNAL,
cv2.CHAIN_APPROX_SIMPLE)[-2] #Find a few masks in the picture
center = None
if len(cnts) > 0: #If the number of whole masks in the picture is greater than one
'''
Find the coordinates of the center point of the object of the target color and the size of the object in
the picture