def load_parameters (num_cameras):
    """
    Initialize global variables.
    """
    global camera_types, demo_type_dir, master_file, demo_num, demo_info,\
           latest_demo_file, cam_stop_request, cam_publish_request, topic_writer

    demo_type_dir = osp.join(demo_files_dir, demo_type)
    if not osp.isdir(demo_type_dir):
        os.mkdir(demo_type_dir)

    # Taken care of outside.
    master_file = osp.join(demo_type_dir, master_name)
    if not osp.isfile(master_file):
        with open(master_file, "w") as f:
            f.write("name: %s\n"%demo_type)
            f.write("h5path: %s\n"%(demo_type+".h5"))
            f.write("demos: \n")

    camera_types = {(i+1):None for i in range(num_cameras)}
    for cam in camera_types:
        with open(osp.join(hd_data_dir,'camera_types','camera%i'%cam),'r') as fh: camera_types[cam] = fh.read()
        save_image_services[cam] = rospy.ServiceProxy("saveImagescamera%i"%cam, SaveImage)
        cam_save_requests[cam] = SaveImageRequest()
        cam_save_requests[cam].start = True
        cam_save_requests[cam].publish = False 

        if camera_types[cam] == "rgb":
            with open(osp.join(hd_data_dir,'camera_types','camera%i_model'%cam),'r') as fh: camera_models[cam] = fh.read()
            
    cam_stop_request = SaveImageRequest()
    cam_stop_request.start = False
    cam_stop_request.publish = False
    
    cam_publish_request = SaveImageRequest()
    cam_publish_request.start = False
    cam_publish_request.publish = True
            
    # Get number of latest demo recorded
    latest_demo_file = osp.join(demo_type_dir, latest_demo_name)
    if osp.isfile(latest_demo_file):
        try:
            with open(latest_demo_file,'r') as fh:
                demo_num = int(fh.read()) + 1
        except: demo_num = 1
    else: demo_num = 1
    
    topics = ['/l_pot_angle', '/r_pot_angle','/segment','/tf']
    topic_types = [Float32, Float32, Segment, tfMessage]
    topic_writer = TopicWriter(topics=topics, topic_types=topic_types)
    yellowprint("Started listening to the different topics.")
import rospy
import time
import roslib
roslib.load_manifest('record_rgbd_service')

from record_rgbd_service.srv import SaveImage, SaveImageRequest, SaveImageResponse
 
rospy.init_node("test_image_save_service")

save_service = rospy.ServiceProxy("saveImagescamera1", SaveImage)

req = SaveImageRequest ()
req.start = True
req.folder_name = "/home/sibi/temp/check_service"

save_service(req)

time.sleep(2)

req.start = False
save_service(req)