图像旋转任意角度不缺失，缺失背景指定颜色填充（python+opencv）图文教程和完整项目代码

效果展示

代码

# -*- coding: utf-8 -*-

import cv2
from math import *
import numpy as np

# 旋转angle角度，缺失背景白色（255, 255, 255）填充
def rotate_bound_white_bg(image, angle):
    # grab the dimensions of the image and then determine the
    # center
    (h, w) = image.shape[:2]
    (cX, cY) = (w // 2, h // 2)

    # grab the rotation matrix (applying the negative of the
    # angle to rotate clockwise), then grab the sine and cosine
    # (i.e., the rotation components of the matrix)
    # -angle位置参数为角度参数负值表示顺时针旋转; 1.0位置参数scale是调整尺寸比例（图像缩放参数），建议0.75
    M = cv2.getRotationMatrix2D((cX, cY), -angle, 1.0)
    cos = np.abs(M[0, 0])
    sin = np.abs(M[0, 1])

    # compute the new bounding dimensions of the image
    nW = int((h * sin) + (w * cos))
    nH = int((h * cos) + (w * sin))

    # adjust the rotation matrix to take into account translation
    M[0, 2] += (nW / 2) - cX
    M[1, 2] += (nH / 2) - cY

    # perform the actual rotation and return the image
    # borderValue 缺失背景填充色彩，此处为白色，可自定义
    return cv2.warpAffine(image, M, (nW, nH),borderValue=(255,255,255))
    # borderValue 缺省，默认是黑色（0, 0 , 0）
    # return cv2.warpAffine(image, M, (nW, nH))

img = cv2.imread("dog.png")
imgRotation = rotate_bound_white_bg(img, 45)

cv2.imshow("img",img)
cv2.imshow("imgRotation",imgRotation)
cv2.waitKey(0)

return cv2.warpAffine(image, M, (nW, nH),borderValue=(255,255,255)) # borderValue 缺失背景色彩，此处为白色，可自定义

return cv2.warpAffine(image, M, (nW, nH)) # borderValue 缺省，默认是黑色（0, 0 , 0）,效果如下

素材