使用Python 2.7的RaspberryPi相機流處理

Question

我在這里找到了以下代碼，用於捕獲來自RaspberryPi攝像機的視頻流。

現在，我要處理視頻流（例如，找到BLOB或顯示視頻）。

為此，我需要將視頻的內容捕獲為數組，例如在此示例中使用名稱frame ：

cv2.imshow('stream', frame)

我通過將其轉換為數組來嘗試

frame = self.stream.array

但有些時候我無法正常工作。

輸出告訴我無法使用流創建數組：

File "Raspberry.py", line 35, in run
    frame = self.stream.array   #creating an array for the stream
AttributeError: '_io.BytesIO' object has no attribute 'array'

有什么想法如何解決嗎？

碼：

import io
import time
import threading
import picamera

# Create a pool of image processors
done = False
lock = threading.Lock()
pool = []

class ImageProcessor(threading.Thread):
    def __init__(self):
        super(ImageProcessor, self).__init__()
        self.stream = io.BytesIO()
        self.event = threading.Event()
        self.terminated = False
        self.start()

    def run(self):
        # This method runs in a separate thread
        global done
        while not self.terminated:
            # Wait for an image to be written to the stream
            if self.event.wait(1):
                try:
                    self.stream.seek(0)

                    frame = self.stream.array   #creating an array for the stream                   

                    cv2.imshow('stream', frame) #should show the livestream



                    # Read the image and do some processing on it
                    #Image.open(self.stream)
                    #...
                    #...
                    # Set done to True if you want the script to terminate
                    # at some point
                    #done=True
                finally:
                    # Reset the stream and event
                    self.stream.seek(0)
                    self.stream.truncate()
                    self.event.clear()
                    # Return ourselves to the pool
                    with lock:
                        pool.append(self)

def streams():
    while not done:
        with lock:
            if pool:
                processor = pool.pop()
            else:
                processor = None
        if processor:
            yield processor.stream
            processor.event.set()
        else:
            # When the pool is starved, wait a while for it to refill
            time.sleep(0.1)

with picamera.PiCamera() as camera:
    pool = [ImageProcessor() for i in range(4)]
    camera.resolution = (640, 480)
    camera.framerate = 30
    camera.start_preview()
    time.sleep(2)
    camera.capture_sequence(streams(), use_video_port=True)

# Shut down the processors in an orderly fashion
while pool:
    with lock:
        processor = pool.pop()
    processor.terminated = True
    processor.join()

Answer 1

如果您確實不需要，基本的picamera軟件包不提供數組功能以防止在Raspberry Pi上進行冗長的numpy編譯。

要安裝numpy數組支持，請嘗試：

pip install --user "picamera[array]"