Raspberry PIでOpenCV（Python）のコマンドがエラーに

###したいこと
Raspberry PIカメラモジュールを使ってカラートラッキングをし、ボールの重心を測定するコードになっています。
同じ事ができるなら多少コードを変えても構いません

コマンドラインでの実行ができない

Thonny上で実行はできるのですがコマンドライン上でpython Cam.pyを実行するとcv2.connectedComponentsWithStatsがエラーになってしまいます。なぜThonnyでは動作するのにコマンドラインでは動かないのでしょうか。

Python
1#!/usr/bin/python
2# -*- coding: utf-8 -*-
3
4from picamera import PiCamera
5from picamera.array import PiRGBArray
6import numpy as np
7import time
8import cv2
9
10#import threading
11
12CAMERA_WIDTH = 688
13CAMERA_HEIGHT = 480
14Xaxis = 10
15Yaxis = 10
16def centor(input):
17    if np.count_nonzero(input) <= 0:
18        return(-20,-20)
19    label = cv2.connectedComponentsWithStats(input)
20    n = label[0] -1
21    data = np.delete(label[2], 0, 0)
22    center = np.delete(label[3], 0, 0)
23    max_index = np.argmax(data[:,4])
24    return center[max_index]
25
26camera = PiCamera()
27camera.resolution = (CAMERA_WIDTH, CAMERA_HEIGHT)
28camera.framerate = 30
29rawCapture = PiRGBArray(camera, size=(CAMERA_WIDTH, CAMERA_HEIGHT))
30time.sleep(0.1)
31for image in camera.capture_continuous(rawCapture, format="bgr", use_video_port=True):
32    stream = image.array
33    #data = np.fromstring(stream.getvalue(), dtype=np.uint8)
34    #image = cv2.imdecode(data, 1)
35    hsv = cv2.cvtColor(stream,cv2.COLOR_BGR2HSV)
36    lower_blue = np.array([160,100,100])
37    upper_blue = np.array([180,200,200])
38    mask = cv2.inRange(hsv,lower_blue, upper_blue)
39    denoize = cv2.medianBlur(mask,5)
40    Xaxis,Yaxis = centor(mask)
41    print(Xaxis,Yaxis)
42    #cv2.circle(mask, (int(Xaxis), int(Yaxis)), 10, (0, 0, 255), 5)
43    cv2.circle(stream, (int(Xaxis), int(Yaxis)), 20, (255, 255, 0), 10)
44    #cv2.imshow('image',mask)
45    cv2.imshow('Mix',stream)
46    key = cv2.waitKey(1) & 0xFF
47
48    rawCapture.truncate(0)
49
50    if key == ord("q"):
51        break
52cv2.destroyAllWindows()

エラー

mmal: mmal_vc_port_enable: failed to enable port vc.null_sink:in:0(OPQV): ENOSPC
mmal: mmal_port_enable: failed to enable connected port (vc.null_sink:in:0(OPQV))0x12e2e10 (ENOSPC)
mmal: mmal_connection_enable: output port couldn't be enabled
Traceback (most recent call last):
  File "Cam.py", line 26, in <module>
    camera = PiCamera()
  File "/usr/lib/python2.7/dist-packages/picamera/camera.py", line 433, in __init__
    self._init_preview()
  File "/usr/lib/python2.7/dist-packages/picamera/camera.py", line 513, in _init_preview
    self, self._camera.outputs[self.CAMERA_PREVIEW_PORT])
  File "/usr/lib/python2.7/dist-packages/picamera/renderers.py", line 558, in __init__
    self.renderer.inputs[0].connect(source).enable()
  File "/usr/lib/python2.7/dist-packages/picamera/mmalobj.py", line 2212, in enable
    prefix="Failed to enable connection")
  File "/usr/lib/python2.7/dist-packages/picamera/exc.py", line 184, in mmal_check
    raise PiCameraMMALError(status, prefix)
picamera.exc.PiCameraMMALError: Failed to enable connection: Out of resources