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TA貢獻(xiàn)1810條經(jīng)驗(yàn) 獲得超4個(gè)贊
是的。從SciPy計(jì)算高斯核的復(fù)雜方法(沒有雙關(guān)語)中,這不是很明顯,但是這是一個(gè)經(jīng)驗(yàn)驗(yàn)證:我將高斯核與一個(gè)a具有單個(gè)項(xiàng)1的向量進(jìn)行卷積,從而獲得了卷積。然后以通常的方式計(jì)算方差,E[X**2] - E[X]**2其中X可以以像素(np.arange(len(a)))表示。
from scipy.ndimage.filters import gaussian_filter
import numpy as np
a = np.zeros((100,))
x = np.arange(len(a))
a[len(a)//2] = 1
for sigma in range(3, 10):
kernel = gaussian_filter(a, sigma)
var = np.sum(x**2*kernel) - np.sum(x*kernel)**2
print("Given sigma {}, empiric value {}".format(sigma, np.sqrt(var)))
輸出:
Given sigma 3, empiric value 2.999207360674749
Given sigma 4, empiric value 3.9987184940057614
Given sigma 5, empiric value 4.998211402871647
Given sigma 6, empiric value 5.997694984501222
Given sigma 7, empiric value 6.997173172490447
Given sigma 8, empiric value 7.996647965992465
Given sigma 9, empiric value 8.99612048649375
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