linerobot/pythonDDS/read_depthimage.py

# -*- coding: utf-8 -*-
"""
Created on 23 Jan 2022

@author: Edward Hage
"""

import numpy as np
import cv2
import struct

from dds import Listener, DomainParticipant, Topic, QosProvider, Qos
from dds import PresentationQosPolicy, PartitionQosPolicy, DDSPresentationAccessScopeKind, DurabilityQosPolicy,DDSDurabilityKind
from idlpython.sensor_msgs.Image_.sensor_msgs.msg.dds_ import Image___TypeSupport

class ImageReader():
   
    class ImageListener(Listener):
        
        def __init__(self):
            Listener.__init__(self)
    
        def on_data_available(self, entity):
            l = entity.take(1)
            print("here")
          
            for (sd, si) in l:
                current_frame = self.convert(sd)
                
                clipmin = 0.3
                clipmax = 2.0
                
                new_frame = current_frame.copy()
                np.clip(new_frame, clipmin, clipmax, out=new_frame)
                new_frame -= clipmin
                new_frame /= (clipmax-clipmin)/255.0
                new_frame = new_frame.astype(dtype=np.uint8, copy=False)

                im_color = cv2.applyColorMap(new_frame, cv2.COLORMAP_AUTUMN)
              
                cv2.imshow("camera", current_frame) # of new_frame
                cv2.waitKey(1) # 1 for automatic update
        
        def convert(self, img_msg):
            # dtype, n_channels = "32F", 1 # hardcoded data from Unity
            # dtype = np.dtype(dtype)
            # dtype = dtype.newbyteorder('>' if img_msg.is_bigendian_ else '<')
            # print( dtype)
            # print("totsize = " + str(len(img_msg.data_)) + "  height = " + str(img_msg.height_) + " width " + str(img_msg.width_))
            
            dt = np.dtype('float32')
            dt = dt.newbyteorder('<')
            #im = np.ndarray(shape=(img_msg.height_, img_msg.width_, 1), dtype = 'float32', buffer = bytearray(img_msg.data_))
            
            im = np.ndarray(shape=(img_msg.height_, img_msg.width_, 1), dtype = dt, buffer = bytearray(img_msg.data_))
            return im

    listener = ImageListener()
    
    def __init__(self, topicname):
        qp = QosProvider('file://DDS_ROSQoS.xml', 'DDS ROSQosProfile')
        dp = DomainParticipant(qos = qp.get_participant_qos())
        sub = dp.create_subscriber(Qos([PresentationQosPolicy(DDSPresentationAccessScopeKind.INSTANCE, False, False), 
                                      PartitionQosPolicy(['']),
                                      DurabilityQosPolicy(DDSDurabilityKind.VOLATILE)]))
        topic = Topic(dp, topicname, Image___TypeSupport(), qp.get_topic_qos(), None)
        self.reader = sub.create_datareader(topic, qp.get_reader_qos(), self.listener)

reader = ImageReader("rt/depth_processor") 

input("Press a key to stop ...")