import cv2
import numpy as np
import matplotlib.pylab as plt
import scipy.misc as misc
'''
src - input image
top, bottom, left, right - border width in number of pixels in corresponding directions
borderType - Flag defining what kind of border to be added. It can be following types:
cv2.BORDER_CONSTANT - Adds a constant colored border. The value should be given as next argument.
cv2.BORDER_REFLECT - Border will be mirror reflection of the border elements, like this : fedcba|abcdefgh|hgfedcb
cv2.BORDER_REFLECT_101 or cv2.BORDER_DEFAULT - Same as above, but with a slight change, like this : gfedcb|abcdefgh|gfedcba
cv2.BORDER_REPLICATE - Last element is replicated throughout, like this: aaaaaa|abcdefgh|hhhhhhh
cv2.BORDER_WRAP - Can't explain, it will look like this : cdefgh|abcdefgh|abcdefg
value - Color of border if border type is cv2.BORDER_CONSTANT
'''
'''
扩充图像边界
• src 输入图像
• top, bottom, left, right 对应边界的像素数目。
• borderType 要添加那种类型的边界,类型如下
– cv2.BORDER_CONSTANT 添加有颜色的常数值边界,还需要下一个参数(value)。
– cv2.BORDER_REFLECT 边界元素的镜像。比如: fedcba|abcde-fgh|hgfedcb
– cv2.BORDER_REFLECT_101 or cv2.BORDER_DEFAULT跟上面一样,但稍作改动。例如: gfedcb|abcdefgh|gfedcba
– cv2.BORDER_REPLICATE 重复最后一个元素。例如: aaaaaa|abcdefgh|hhhhhhh
– cv2.BORDER_WRAP 不 知 道 怎 么 说 了, 就 像 这 样: cdefgh|abcdefgh|abcdefg
• value 边界颜色,如果边界的类型是 cv2.BORDER_CONSTANT
'''
BLUE=[255,0,0]
img1=cv2.imread('images/33.jpg')
replicate = cv2.copyMakeBorder(img1,10,10,10,10,cv2.BORDER_REPLICATE)
reflect = cv2.copyMakeBorder(img1,10,10,10,10,cv2.BORDER_REFLECT)
reflect101 = cv2.copyMakeBorder(img1,10,10,10,10,cv2.BORDER_REFLECT_101)
wrap = cv2.copyMakeBorder(img1,10,10,10,10,cv2.BORDER_WRAP)
constant= cv2.copyMakeBorder(img1,10,10,10,10,cv2.BORDER_CONSTANT,value=BLUE)
plt.subplot(231),plt.imshow(img1,'gray'),plt.title('ORIGINAL')
plt.subplot(232),plt.imshow(replicate,'gray'),plt.title('REPLICATE')
plt.subplot(233),plt.imshow(reflect,'gray'),plt.title('REFLECT')
plt.subplot(234),plt.imshow(reflect101,'gray'),plt.title('REFLECT_101')
plt.subplot(235),plt.imshow(wrap,'gray'),plt.title('WRAP')
plt.subplot(236),plt.imshow(constant,'gray'),plt.title('CONSTANT')
plt.show()
