71 lines
2.3 KiB
Python
71 lines
2.3 KiB
Python
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# 图像的透视校正
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import cv2
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import numpy as np
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import math
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# 读入待处理的图像并显示
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img = cv2.imread("./data/shu3.jpg")
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cv2.imshow("1_yuanshituxima", img)
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# 灰度化 并显示
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img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
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cv2.imshow("2.huidu", img_gray)
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# 模糊化处理 去掉过小的细节
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blurred = cv2.GaussianBlur(img_gray, (5, 5), 0)
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cv2.imshow("3.mohu", blurred)
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# 膨胀-抖小的细节合并
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dilate = cv2.dilate(blurred, (3, 3))
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cv2.imshow("4_pengzhang", dilate)
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# 边缘提取
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canny = cv2.Canny(dilate, 50, 240)
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cv2.imshow("5_bianyuntiqu", canny)
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# 轮廓检测
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imag, cnts, hie = cv2.findContours(canny.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
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# 绘制轮廓
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img_cnt = cv2.drawContours(img.copy(), cnts, -1, (0, 0, 255), 2)
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cv2.imshow("6_lunkuxian", img_cnt)
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docCnt = None # 定义一个空数组
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# 计算面积, 排序
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if len(cnts) > 0:
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cnts = sorted(cnts, key=cv2.contourArea, reverse=True)
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for c in cnts:
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peri = cv2.arcLength(c, True) # 求出该轮廓线的周长
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approx = cv2.approxPolyDP(c, 0.02 * peri, True) # 轮廓线的多边形组合
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if len(approx) == 4: # 找到边为4的多边形
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docCnt = approx # 将找到的多边形赋值给另外一个变量docCnt
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break
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# 绘制找到的四边形的点,画圆
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points = []
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for peak in docCnt:
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peak = peak[0]
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print("peak:", peak)
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cv2.circle(img_cnt, tuple(peak), 10, (0, 255, 0), 2) # 圆所在的图像, 圆心, 半径, 颜色, 线宽
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points.append(peak)
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cv2.imshow("7-sibianxingdingdian", img_cnt)
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print("points:", points)
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# 校正
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# 原纸张逆时针方向的4个角点
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src = np.float32([points[0], points[1], points[2], points[3]])
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# 根据勾股定理计算宽度,再做透视变换
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h = int(math.sqrt((points[1][0] - points[0][0]) ** 2 + (points[1][1] - points[0][1]) ** 2)) # 高度
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w = int(math.sqrt((points[2][0] - points[1][0]) ** 2 + (points[2][1] - points[1][1]) ** 2)) # 宽度
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print("w, h", w, h)
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dst = np.float32([[0, 0], [0, h], [w, h], [w, 0]])
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M = cv2.getPerspectiveTransform(src, dst) # 生成透视矩阵
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result = cv2.warpPerspective(img.copy(), M, (w, h)) # 透视变换
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cv2.imshow("8_leguo", result)
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cv2.waitKey()
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cv2.destroyAllWindows()
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