插值

Bilinear interpolation would be order=1, 
nearest is order=0, 
and cubic is the default (order=3).

舉例說明

import numpy as np
import scipy.ndimage

x = np.arange(64).reshape(8,8)

print 'Original array:'
print x

print 'Resampled by a factor of 2 with nearest interpolation:'
print scipy.ndimage.zoom(x, 2
 
, order=0)


print 'Resampled by a factor of 2 with bilinear interpolation:'
print scipy.ndimage.zoom(x, 2, order=1)


print 'Resampled by a factor of 2 with cubic interpolation:'
print scipy.ndimage.zoom(x, 2, order=3)

print 'Downsampled by a factor of 0.5 with default interpolation:'
print(scipy.ndimage.zoom(x, 0.5
 
))

結果

Original array:
array([[ 0,  1,  2,  3,  4,  5,  6,  7],
       [ 8,  9, 10, 11, 12, 13, 14, 15],
       [16, 17, 18, 19, 20, 21, 22, 23],
       [24, 25, 26, 27, 28, 29, 30, 31],
       [32, 33, 34, 35, 36, 37, 38, 39],
       [40, 41, 42, 43, 44, 45, 46, 47],
       [48, 49, 50, 51, 52, 53, 54, 55]
 
,
       [56, 57, 58, 59, 60, 61, 62, 63]])
Resampled by a factor of 2 with nearest interpolation:
[[ 0  0  1  1  2  2  3  3  4  4  5  5  6  6  7  7]
 [ 0  0  1  1  2  2  3  3  4  4  5  5  6  6  7  7]
 [ 8  8  9  9 10 10 11 11 12 12 13 13 14 14 15 15]
 [ 8  8  9  9 10 10 11 11 12 12 13 13 14 14 15 15]
 [16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23]
 [16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23]
 [24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31]
 [24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31]
 [32 32 33 33 34 34 35 35 36 36 37 37 38 38 39 39]
 [32 32 33 33 34 34 35 35 36 36 37 37 38 38 39 39]
 [40 40 41 41 42 42 43 43 44 44 45 45 46 46 47 47]
 [40 40 41 41 42 42 43 43 44 44 45 45 46 46 47 47]
 [48 48 49 49 50 50 51 51 52 52 53 53 54 54 55 55]
 [48 48 49 49 50 50 51 51 52 52 53 53 54 54 55 55]
 [56 56 57 57 58 58 59 59 60 60 61 61 62 62 63 63]
 [56 56 57 57 58 58 59 59 60 60 61 61 62 62 63 63]]

Resampled by a factor of 2 with bilinear interpolation:
[[ 0  0  1  1  2  2  3  3  4  4  5  5  6  6  7  7]
 [ 4  4  5  5  6  6  7  7  7  8  8  9  9 10 10 11]
 [ 7  8  8  9  9 10 10 11 11 12 12 13 13 14 14 14]
 [11 12 12 13 13 14 14 14 15 15 16 16 17 17 18 18]
 [15 15 16 16 17 17 18 18 19 19 20 20 21 21 21 22]
 [19 19 20 20 21 21 21 22 22 23 23 24 24 25 25 26]
 [22 23 23 24 24 25 25 26 26 27 27 28 28 28 29 29]
 [26 27 27 28 28 28 29 29 30 30 31 31 32 32 33 33]
 [30 30 31 31 32 32 33 33 34 34 35 35 35 36 36 37]
 [34 34 35 35 35 36 36 37 37 38 38 39 39 40 40 41]
 [37 38 38 39 39 40 40 41 41 42 42 42 43 43 44 44]
 [41 42 42 42 43 43 44 44 45 45 46 46 47 47 48 48]
 [45 45 46 46 47 47 48 48 49 49 49 50 50 51 51 52]
 [49 49 49 50 50 51 51 52 52 53 53 54 54 55 55 56]
 [52 53 53 54 54 55 55 56 56 56 57 57 58 58 59 59]
 [56 56 57 57 58 58 59 59 60 60 61 61 62 62 63 63]]

Resampled by a factor of 2 with cubic interpolation:
[[ 0  0  1  1  2  2  3  3  4  4  5  5  6  6  7  7]
 [ 2  3  3  4  4  5  5  6  6  7  7  8  8  9  9  9]
 [ 7  8  8  9  9 10 10 11 11 12 12 12 13 13 14 14]
 [12 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19]
 [15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22]
 [19 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26]
 [22 23 23 24 24 25 25 26 26 27 27 27 28 28 29 29]
 [26 26 27 28 28 28 29 29 30 30 31 31 32 32 33 33]
 [30 30 31 31 32 32 33 33 34 34 35 35 35 36 37 37]
 [34 34 35 35 36 36 36 37 37 38 38 39 39 40 40 41]
 [37 38 38 39 39 40 40 41 41 42 42 43 43 44 44 44]
 [41 41 42 42 43 43 44 44 45 45 46 46 47 47 48 48]
 [44 45 45 46 46 47 47 48 48 49 49 50 50 51 51 51]
 [49 49 50 50 51 51 51 52 52 53 53 54 54 55 55 56]
 [54 54 54 55 55 56 56 57 57 58 58 59 59 60 60 61]
 [56 56 57 57 58 58 59 59 60 60 61 61 62 62 63 63]]


Downsampled by a factor of 0.5 with default interpolation:
[[ 0  2  5  7]
 [19 21 23 26]
 [37 40 42 44]
 [56 58 61 63]]

參考文獻