xml_file_bridge.py

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#!/usr/bin/env python
# -*- coding: utf-8 -*-
## @author Fabian Wenzelmann
#  @date 03/10/2011
import roslib
roslib.load_manifest('face_contour_detector')
import rospy
import xml_image_information
from face_contour_detector.srv import *
from face_contour_detector.msg import *
import image_information
import cv_bridge

## @package face_contour_detector.image_information.xml_file_bridge
#  This package implements the services srv/XMLReader.srv and srv/XMLWriter.srv It is used to save and read image datebase xml files.
#  @author Fabian Wenzelmann

## @brief Handler to save a xml file, see srv/XMLWriter.srv
#  @param req the request object
def save_handler(req):
    database = xml_image_information.XMLImageInformationDatabase()
    for image in req.images:
        database.append(_gen_dict(image))
    try:
        database.write_file(req.file_name)
        return XMLWriterResponse(True)
    except:
        raise
        return XMLWriterResponse(False)

## @brief handler to load a xml file, see srv/XMLReader.srv
#  @param req request object
def load_handler(req):
    path = req.file_name
    database = xml_image_information.XMLImageInformationDatabase()
    try:
        database.load_file(path)
        return XMLReaderResponse(_gen_list(database.images), True)
    except:
        raise
        return XMLReaderResponse([], False)

## @brief get default information about an image, see srv/ImageInformationBridge.srv        
#  @param req request object
def information_handler(req):
    extractor = image_information.InformationExtractor()
    extractor.add_default_extractors()
    bridge = cv_bridge.CvBridge()
    img = bridge.imgmsg_to_cv(req.input_image)
    props = extractor.to_dict(img)
    entries = []
    for entry_name, (value, type_name) in props.items():
        entries.append(xml_image_entry(entry_name.encode("ascii"), type_name.encode("ascii"), str(value).encode("ascii")))
    return ImageInformationBridgeResponse(xml_image(entries))

def _gen_dict(image):
    result = {}
    for entry in image.entries:
        get_value = None
        if entry.type == "int":
            get_value = int
        elif entry.type == "float":
            get_value = float
        else:
            get_value = str
        result[entry.entry_name] = get_value(entry.content), entry.type
    return result
    
def _gen_list(images):
    image_list = []
    for image in images:
        entries = []
        for entry_name, (value, type_name) in image.items():
            entries.append( xml_image_entry(entry_name.encode("ascii"), type_name.encode("ascii"), str(value).encode("ascii")) )
        image_list.append(xml_image(entries))
    return image_list
    
def xml_file_bridge_init_node():
    rospy.init_node("xml_file_bridge_server")
    s1 = rospy.Service('xml_file_bridge', XMLWriter, save_handler)
    s2 = rospy.Service("xml_file_bridge_loader", XMLReader, load_handler)
    s3 = rospy.Service("image_information", ImageInformationBridge, information_handler)
    rospy.spin()
    
if __name__ == "__main__":
    xml_file_bridge_init_node()