def flip(src, flipCode, dst=None): # real signature unknown; restored from __doc__
"""
flip(src, flipCode[, dst]) -> dst
. @brief Flips a 2D array around vertical, horizontal, or both axes.
围绕垂直轴，水平轴或两个轴翻转2D数组。
.
. The function cv::flip flips the array in one of three different ways (row
. and column indices are 0-based):
函数cv :: flip以三种不同的方式之一翻转数组（行和列索引均基于0）：
. \f[\texttt{dst} _{ij} =
. \left\{
. \begin{array}{l l}
. \texttt{src} _{\texttt{src.rows}-i-1,j} & if\; \texttt{flipCode} = 0 \\
. \texttt{src} _{i, \texttt{src.cols} -j-1} & if\; \texttt{flipCode} > 0 \\
. \texttt{src} _{ \texttt{src.rows} -i-1, \texttt{src.cols} -j-1} & if\; \texttt{flipCode} < 0 \\
. \end{array}
. \right.\f]
. The example scenarios of using the function are the following:
以下是使用该函数的示例方案：
. * Vertical flipping of the image (flipCode == 0) to switch between
. top-left and bottom-left image origin. This is a typical operation
. in video processing on Microsoft Windows\* OS.
图像的垂直翻转（flipCode == 0）以在左上和左下图像原点之间切换。
这是Microsoft Windows \ * OS上视频处理中的典型操作。
. * Horizontal flipping of the image with the subsequent horizontal
. shift and absolute difference calculation to check for a
. vertical-axis symmetry (flipCode \> 0).
图像的水平翻转以及随后的水平移位和绝对差计算，以检查垂直轴对称性（flipCode \> 0）。
. * Simultaneous horizontal and vertical flipping of the image with
. the subsequent shift and absolute difference calculation to check
. for a central symmetry (flipCode \< 0).
同时进行图像的水平和垂直翻转，以及随后的偏移和绝对差计算，以检查中心对称性（flipCode \ <0）。
. * Reversing the order of point arrays (flipCode \> 0 or
. flipCode == 0).
反转点数组的顺序（flipCode \> 0或flipCode == 0）。
. @param src input array.
. @param dst output array of the same size and type as src.
. @param flipCode a flag to specify how to flip the array; 0 means
. flipping around the x-axis and positive value (for example, 1) means
. flipping around y-axis. Negative value (for example, -1) means flipping
. around both axes.
用于指定如何翻转数组的标志； 0表示绕x轴翻转，正值（例如1）表示绕y轴翻转。
负值（例如-1）表示围绕两个轴翻转。
. @sa transpose , repeat , completeSymm
"""
pass
公式1：
示例代码：
# -*- coding: utf-8 -*-
"""
@File : 20200119_测试图片镜像.py
@Time : 2020/1/19 16:27
@Author : Dontla
@Email : [email protected]
@Software: PyCharm
"""
import cv2
# 读取图像
img = cv2.imread('girl-3421489_1920.jpg')
# print(img.shape) # (1280, 1920, 3)
# 沿x轴翻转
cv2.imshow('win1', cv2.flip(img, 0))
# 沿y轴翻转
cv2.imshow('win2', cv2.flip(img, 1))
# 沿x轴y轴翻转
cv2.imshow('win3', cv2.flip(img, -1))
cv2.waitKey(0)
结果：
参考文章：opencv3+python3完成图片镜像实现
