OpenCV-python学习笔记（二）——image processing图像基本处理

image processing图像处理

1 image transfomations图像变换

1.1 translation平移

# 格式为[1,0,tx]和[0,1,ty]，其中tx和ty分别为横向和纵向，正数表示向下和向右
# 负数表示向上和向左
M = np.float32([[1, 0, 25], [0, 1, 50]])
shifted = cv2.warpAffine(image, M, (image.shape[1], image.shape
[0]))
cv2.imshow("Shifted Down and Right", shifted)

封装成一个函数的写法

# 子函数的写法
import numpy as np
import cv2
def translate(image, x, y):
    # 定义平移矩阵
    M = np.float32([[1, 0, x], [0, 1, y]])
    # 使用warpAffine方法进行变换
    shifted = cv2.warpAffine(image, M, (image.shape[1], image.
    shape[0]))
    return shifted
# 直接调用函数
shifted = imutils.translate(image, 0, 100)
cv2.imshow("Shifted Down", shifted)
cv2.waitKey(0)

1.2 rotation旋转

(height, width) = image.shape[:2]
center = (width//2, height