前言
日常生活中，手残党们经常会把一些照片拍歪，比如拍个证件、试卷、PPT什么的，
比如下面这本书的封面原本是个矩形，随手一拍就成了不规则四边形
想要把它变成规则的矩形，有什么办法呢？
你一定想到了 PS，因为网上很多教程就是这么教的
打开PS 
下面我们来写个程序，自动将图片恢复到任意矩形！
程序实现
1. 打开图片并显示
import cv2 as cv import numpy as np path = './book.jpg' src = cv.imread(path) def get_window_size(src, bound=600): h,w = src.shape[0], src.shape[1] if h > w: h, w = bound, int(w*bound/h) else: h, w = int(h*bound/w), bound return (h, w) h, w = get_window_size(src) win_name = 'RecAdjust' cv.namedWindow(win_name, cv.WINDOW_NORMAL) cv.resizeWindow(win_name, width=w, height=h) cv.imshow(win_name, src) cv.waitKey(0) cv.destroyAllWindows()
2. 在图片中标记四个角点
src_copy = src.copy()
class Indexer:
def __init__(self, bound=4):
self.id = 0
self.bound=bound
def get_id(self):
self.id = (self.id+1)%self.bound
return (self.id-1)%self.bound+1
def on_EVENT_LBUTTONDOWN(event, x, y, flags, param):
if event == cv.EVENT_LBUTTONDOWN:
img = param['src']
win_name = param['window']
indexer = param['indexer']
points = param['points']
curr_id = indexer.get_id()
points.append((x,y))
print('第{}个顶点: ({},{})'.format(curr_id, x, y))
cv.circle(img, (x, y), 10, (0, 0, 255), thickness = 2)
cv.putText(
img,
str(curr_id), # 文字
(x, y), # 坐标
cv.FONT_HERSHEY_PLAIN,
5, # 字号
(0,0,255), # 字体颜色
thickness = 2 # 粗细
)
cv.imshow(win_name, img)
points = []
indexer = Indexer()
win_name = 'RecAdjust'
cv.namedWindow(win_name, cv.WINDOW_NORMAL)
cv.resizeWindow(win_name, width=w, height=h)
cv.imshow(win_name, src)
cv.setMouseCallback(win_name, on_EVENT_LBUTTONDOWN, param={'src':src,'window':win_name, 'indexer':indexer, 'points':points})
cv.waitKey(0)
cv.destroyAllWindows()
print(points)
3. 设定输出矩形大小
# W = int(input('输出图片宽度:'))
# H = int(input('输出图片高度:'))
W,H = 600, 800
target_points = [(0,0),(W,0),(W,H),(0,H)]
4. 求解透视变换矩阵
points, target_points = np.array(points, dtype=np.float32), np.array(target_points, dtype=np.float32)
M = cv.getPerspectiveTransform(points, target_points)
print('透视变换矩阵:',M)
5. 透视变换并保存图片
result = cv.warpPerspective(src_copy, M, (0, 0)) result = result[:H, :W] win_name = 'Result' cv.namedWindow(win_name, cv.WINDOW_NORMAL) cv.resizeWindow(win_name, width=W, height=H) cv.imshow(win_name, result) cv.waitKey(0) cv.destroyAllWindows() output_file = 'result.jpg' cv.imwrite(output_file, result)
结果如下
结果没有想象的完美，是因为书的封面已经不是一个平面了，书角翘起。。。
如果图片中的矩形在一个平面上的话，效果还是挺不错的！！
完整代码下载
可关注后免费下载喔：https://download.csdn.net/download/itnerd/12819535（本地下载）
总结