joblib.Parallel（）速度比skimage慢于单个

Question

我必须为一叠图像的每个切片应用一个2D过滤器，我想并行化分析。但是，下面的代码比正常的for循环运行慢。同样，增加n_jobs也会增加处理时间，对于n_jobs = 1更快，而对于[[n_jobs = 6则更慢。

import numpy as np 
from joblib import Parallel, delayed
from skimage.restoration import denoise_tv_chambolle

arr = np.random.rand(50,50,50)

def f(arr):
    arr_h = denoise_tv_chambolle(arr, weight=0.1, multichannel=True)
    return arr_h

Parallel(n_jobs=6, backend="threading")(delayed(f)(i) for i in arr)

Answer 1

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