example_temp.py

#!/usr/bin/env python
from __future__ import print_function

import roslib
roslib.load_manifest('face_recognition_ros')
import sys
import rospy
import cv2
from std_msgs.msg import String
from sensor_msgs.msg import Image
from cv_bridge import CvBridge, CvBridgeError

class image_converter:

  def __init__(self):
    imout = rospy.get_param('~image_output', "image_raw")

    self.image_pub = rospy.Publisher(imout,Image, queue_size=1)
    imin = rospy.get_param('~image_input', "videofiles/image_raw")

    self.bridge = CvBridge()
    self.image_sub = rospy.Subscriber(imin,Image,self.callback)

  def callback(self,data):
    #rospy.loginfo_once("reached callback. that means I can read the Subscriber!")
    try:
      cv_image = self.bridge.imgmsg_to_cv2(data, "bgr8")
      print((cv_image.dtype))
    except CvBridgeError as e:
      print(e)

    (rows,cols,channels) = cv_image.shape
    if cols > 60 and rows > 60 :
      cv2.circle(cv_image, (50,50), 10, 255)

    #cv2.imshow("Image window", cv_image)
    #cv2.waitKey(3)

    try:
      self.image_pub.publish(self.bridge.cv2_to_imgmsg(cv_image, "bgr8"))
    except CvBridgeError as e:
      print(e)

def main(args):
  rospy.init_node('image_converter', anonymous=True)
  ic = image_converter()

  try:
    rospy.spin()
  except KeyboardInterrupt:
    print("Shutting down")
  cv2.destroyAllWindows()

if __name__ == '__main__':
    main(sys.argv)