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clover/clover/examples/camera.py
2022-11-07 20:09:15 +06:00

65 lines
1.7 KiB
Python

# Information: https://clover.coex.tech/camera
# Example on basic working with the camera and image processing:
# - cuts out a central square from the camera image;
# - publishes this cropped image to the topic `/cv/center`;
# - computes the average color of it;
# - prints its name to the console.
import rospy
import cv2
from sensor_msgs.msg import Image
from cv_bridge import CvBridge
from clover import long_callback
rospy.init_node('cv')
bridge = CvBridge()
printed_color = None
center_pub = rospy.Publisher('~center', Image, queue_size=1)
def get_color_name(h):
if h < 15: return 'red'
if h < 30: return 'orange'
elif h < 60: return 'yellow'
elif h < 90: return 'green'
elif h < 120: return 'cyan'
elif h < 150: return 'blue'
elif h < 170: return 'magenta'
else: return 'red'
@long_callback
def image_callback(msg):
img = bridge.imgmsg_to_cv2(msg, 'bgr8')
# convert to HSV to work with color hue
img_hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
# cut out a central square
w = img.shape[1]
h = img.shape[0]
r = 20
center = img_hsv[h // 2 - r:h // 2 + r, w // 2 - r:w // 2 + r]
# compute and print the average hue
mean_hue = center[:, :, 0].mean()
color = get_color_name(mean_hue)
global printed_color
if color != printed_color:
print(color)
printed_color = color
# publish the cropped image
center = cv2.cvtColor(center, cv2.COLOR_HSV2BGR)
center_pub.publish(bridge.cv2_to_imgmsg(center, 'bgr8'))
# process every frame:
image_sub = rospy.Subscriber('main_camera/image_raw', Image, image_callback, queue_size=1)
# process 5 frames per second:
# image_sub = rospy.Subscriber('main_camera/image_raw_throttled', Image, image_callback, queue_size=1)
rospy.spin()