What is the best way to record RGB and Depth data from a Kinect using Openni?
I'm attempting to record short (~10s) video streams from a kinect. Ideally I'd like to output two video files after recording is finished: one file for RGB and the other file for depth (I can save a series of images rather than video file if that's not possible, but that tends to be space intensive, so I'd prefer not to do that). This is so I can process the data later. I have been searching for the past few days around the internet, and while I have found many resources and posts that are close to what I want to do, none of them are quite exactly what I'm looking for. I'm writing in Python, which is relevant since a lot of the posts I've found refer to C++ code, but I can never seem to find the equivalent function calls for Python.
Here's what I've got at the moment, but it is very hacky and doesn't really work. For recording the RGB data, I use image_view extract_images. I make this function call:
subprocess.Popen(["rosrun","image_view","extract_images","_sec_per_frame:=0.01","image:=camera/rgb/image_color"], cwd="temp/rgb/", stdout=DEVNULL)
To record the depth data, I wrote a class that subscribes to the "/camera/depth/image_rect" topic and then writes out the images to files:
class ImageConverter:
NUM_THREADS = 1
def __init__(self):
self.count = 0
self.todo = Queue.Queue()
self.stop = False
self.sub = None
self.threads = None
self.countLock = threading.Lock()
def __getCounter(self):
self.countLock.acquire()
c = self.count
self.count = self.count + 1
self.countLock.release()
ret = str(c)
while len(ret) < 4:
ret = "0" + ret
return ret
def __callback(self, data):
self.todo.put(data)
def __processImage(self,data):
bridge = CvBridge()
try:
source = bridge.imgmsg_to_cv(data, "32FC1")
except CvBridgeError, e:
print e
return
ret = cv.CreateImage((data.width, data.height), 8, 3)
mx = 0.0
for i in range(data.width):
for j in range(data.height):
d = source[j,i]
if d > mx:
mx = d
for i in range(source.width):
for j in range(source.height):
v = source[j,i]/mx*255
ret[j,i] = (v,v,v)
return ret
def startRecording(self,topic):
self.stop = False
def processor():
rate = rospy.Rate(100.0)
while (not self.stop) or (not self.todo.empty()):
if not self.todo.empty():
data = self.todo.get()
img = self.__processImage(data)
c = self.__getCounter()
cv.SaveImage("depth/frame" + c + ".jpg", img)
print("[ImageConverter]: image saved " + c + "/" + str(self.todo.qsize()))
rate.sleep()
self.threads = []
for i in range(ImageConverter.NUM_THREADS):
t = threading.Thread(target=processor, args = ())
t.daemon = True
t.start()
self.threads.append(t)
self.sub = rospy.Subscriber(topic, Image, self.__callback)
def stopRecording(self):
self.sub.unregister()
self.stop = True
for t in self.threads:
t.join()
As you can see in the __processImage method, I had to manually convert the image from 32FC1 to bgr8, since everytime I try to call the cv_bridge method imgmsg_to_cv with ...
