并行图像分割

Question

跟进问题利用Python库进行图像处理

我想使用多处理并行分析几个图像：

class SegmentationType(object):
    DISPLAY_NAME = "invalid"

    def __init__(self, filename, path):
        self.filename = filename
        self.path = path
        self.input_data = None
        self.output_data = None


    def read_image(self):
        self.input_data =  cv2.imread(self.path + self.filename)[1]

    def write_image(self):
        cv2.imwrite(self.path + self.filename.split('.')[0] + '_' + self.DISPLAY_NAME + '.png', self.output_data)

    def process(self):
        # override in derived classes to perform an actual segmentation
        pass

    def start_pipeline(self):
        self.read_image()
        self.process()
        self.write_image()

class HSV_Segmenter(SegmentationType):
    DISPLAY_NAME = 'HSV'

    def process(self):
        source = rgb_to_hsv(self.input_data)
        self.output_data = treshold_otsu(source)


class LabSegmenter(SegmentationType):
    DISPLAY_NAME = 'LAB'

    def process(self):
        source = rgb_to_lab(self.input_data)
        self.output_data = global_threshold(source)


segmenter_class = {
'hsv': HSV_Segmentation,
'lab': LAB_Segmenter
}.get(procedure)

if not segmenter_class:
    raise ArgumentError("Invalid segmentation method '{}'".format(procedure))

for img in images:
    os.chdir(img_dir)
    processor =  = segmenter_class(img, img_dir, procedure)
    processor.start_pipeline()

到目前为止我尝试过的是：

image_lst = os.listdir(my_image_path)

# We split the list into sublist with 5 elements because of 512 GB RAM limitation
if len(image_lst) > 4:
    nr_of_sublists = (int(len(image_lst)/2.5))
    image_sub_lst  =(np.array_split(image_lst, nr_of_sublists))
else:
    image_sub_lst = [image_lst]

# We do the analysis for each sublist
for sub_lst in image_sub_lst:
    print (sub_lst)
    pool = multiprocessing.Pool(8)
    
    # Call the processor 
    processor =  = segmenter_class(img, img_dir, procedure)
    processor.start_pipeline()
    # How to call map???
    pool.map(?, sub_lst)
    pool.terminate()

Answer 1

--对

版本的警告

下面的许多建议假设您使用的是Python 3。

裸继承

class SegmentationType(object):

可以是

class SegmentationType:

抽象静力学

DISPLAY_NAME = "invalid"

不应该真正分配一个值。相反，

DISPLAY_NAME: str

解包装imread

文献资料非常无助:它说imread返回"retval“。考虑到您的用法，很明显现实更加复杂，因为您正在对其进行索引。试着拆开包装：

_, self.input_data = cv2.imread(self.path + self.filename)

抽象方法

process应该raise NotImplementedError在基础上。

工厂

您有一个工厂字典，应该转换成一个方法，如下所示

def get_segmenter(name: str) -> Type[SegmentationType]:
    return {
        t.DISPLAY_NAME: t
        for t in (HSVSegmenter, LABSegmenter)
    }[name]

外括号

这两种情况都没有：

nr_of_sublists = (int(len(image_lst)/2.5))
image_sub_lst  =(np.array_split(image_lst, nr_of_sublists))

需要外括号。

语法

这肯定是打错了？这将不会运行：

processor =  = segmenter_class(img, img_dir, procedure)

这一点也不会：

pool.map(?, sub_lst)