運行python多進程進行圖像處理

Question

我有一個python函數，它接受圖像路徑並根據圖像是否黑色輸出true或false。我想在同一臺機器上處理多個圖像，並且如果其中一個圖像不是黑色的，則會停止該過程。我在這裏讀了很多python，芹菜等多處理，但我不知道從哪裏開始。

Answer 1

我會建議看看Pools輕鬆創建流程。如果你需要有一些共享狀態，在這種情況下，找到一個表示非黑色圖像的布爾值，請看Managers。

更新：這裏是我的意思的例子。

import multiprocessing.Manager as Manager 
import multiprocessing.Pool as Pool 

m = Manager() 
p = Pool(processes=5) 

state_info = m.dict() 
state_info['image_found'] = False 

def processImage(img): 

    # ... Process Image ... 

    if imageIsBlack(img): 
     state_info['image_found'] = True 
     p.terminate() 

p.apply(processImage, imageList) 

if state_info['image_found']: 
    print 'There was a black image!!' 
else: 
    print 'No black images were found.' 

Answer 2

最後，這對我很好。從示例here複製它。爲了說明的目的，我將_isImgNonBlack函數和圖像序列替換爲0和1的列表，其中0是黑色圖像和1個非黑色圖像。

import multiprocessing 

def isImgNonBlack(result_queue, imgSeq): 
    for img in imgSeq: 
     # If a non-black is found put a result 
     if img==1: 
      result_queue.put(1) 

    # else put a zero as the result 
    result_queue.put(0) 

if __name__ == '__main__': 
    processs = [] 
    result_queue = multiprocessing.Queue() 
    nbProc = 20 

    # making a fake list of images with 
    # 10,000 0's follwed by a single 1 
    images = [0 for n in range(10000)] 
    images.append(1) 

    for n in range(nbProc): # start processes crawling for the result 
     process = multiprocessing.Process(target=isImgNonBlack, args=[result_queue, images]) 
     process.start() 
     processs.append(process) 
     print 'Starting Process : %s' % process 

    result = result_queue.get() # waits until any of the proccess have `.put()` a result 

    for process in processs: # then kill them all off 
     process.terminate() 

    # finally print the result 
    print "Seq have a non black img: %s" % result