python 图像插值 最近邻、双线性、双三次实例
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2020-09-16
13:49:53
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python 图像插值图像插值 最近邻、双线性、双三次实例最近邻、双线性、双三次实例
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跟随小编过来看看吧
最近邻：最近邻：
import cv2
import numpy as np
def function(img):
height,width,channels =img.shape
emptyImage=np.zeros((2048,2048,channels),np.uint8)
sh=2048/height
sw=2048/width
for i in range(2048):
for j in range(2048):
x=int(i/sh)
y=int(j/sw)
emptyImage[i,j]=img[x,y]
return emptyImage
img=cv2.imread("e:\lena.bmp")
zoom=function(img)
cv2.imshow("nearest neighbor",zoom)
cv2.imshow("image",img)
cv2.waitKey(0)
双线性：双线性：
import cv2
import numpy as np
import math
def function(img,m,n):
height,width,channels =img.shape
emptyImage=np.zeros((m,n,channels),np.uint8)
value=[0,0,0]
sh=m/height
sw=n/width
for i in range(m):
for j in range(n):
x = i/sh
y = j/sw
p=(i+0.0)/sh-x
q=(j+0.0)/sw-y
x=int(x)-1
y=int(y)-1
for k in range(3):
if x+1<m and y+1<n:
value[k]=int(img[x,y][k]*(1-p)*(1-q)+img[x,y+1][k]*q*(1-p)+img[x+1,y][k]*(1-q)*p+img[x+1,y+1][k]*p*q)
emptyImage[i, j] = (value[0], value[1], value[2])
return emptyImage
img=cv2.imread("e:\lena.bmp")
zoom=function(img,2048,2048)
cv2.imshow("Bilinear Interpolation",zoom)
cv2.imshow("image",img)
cv2.waitKey(0)
双三次：双三次：
import cv2
import numpy as np
import math
def S(x):
x = np.abs(x)
if 0 <= x < 1:
return 1 - 2 * x * x + x * x * x
if 1 <= x < 2:
return 4 - 8 * x + 5 * x * x - x * x * x
else:
return 0
def function(img,m,n):
height,width,channels =img.shape
emptyImage=np.zeros((m,n,channels),np.uint8)
sh=m/height
sw=n/width
for i in range(m):
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