Python+OpenCV之形态学的操作方法是什么
一、 腐蚀与膨胀
1.1 腐蚀操作
import cv2import numpy as npimg = cv2.imread('DataPreprocessing/img/dige.png')cv2.imshow("img", img)cv2.waitKey(0)cv2.destroyAllWindows()
dige.png原图1展示(注: 没有原图的可以截图下来保存本地。
腐蚀1轮次之后~ (iterations = 1)
kernel = np.ones((3, 3), np.uint8)erosion = cv2.erode(img, kernel, iterations=1)cv2.imshow('erosion', erosion)cv2.waitKey(0)cv2.destroyAllWindows()
腐蚀结果展示图2:
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腐蚀圆多次的效果,以及腐蚀原理
pie = cv2.imread('DataPreprocessing/img/pie.png')cv2.imshow('pie', pie)cv2.waitKey(0)cv2.destroyAllWindows()
pie.png原图3:
腐蚀原理, 其中滤波器的大小越大腐蚀的程度越大 图4:
kernel = np.ones((30, 30), np.uint8)erosion_1 = cv2.erode(pie, kernel, iterations=1)erosion_2 = cv2.erode(pie, kernel, iterations=2)erosion_3 = cv2.erode(pie, kernel, iterations=3)res = np.hstack((erosion_1, erosion_2, erosion_3))cv2.imshow('res', res)cv2.waitKey(0)cv2.destroyAllWindows()
圆腐蚀三次结果展示图5:
1.2 膨胀操作
kernel = np.ones((3, 3), np.uint8)dige_dilate = erosiondige_dilate = cv2.dilate(erosion, kernel, iterations=1)cv2.imshow('dilate', dige_dilate)cv2.waitKey(0)cv2.destroyAllWindows()
膨胀之前图2,发现线条变粗,跟原图对比的线条相差无几,但是没了那些长须装的噪音,图6:
膨胀圆多次的效果,以及膨胀原理与腐蚀相反,有白色点的滤波器则滤波器内数据全变为白色。
pie = cv2.imread('DataPreprocessing/img/pie.png')kernel = np.ones((30, 30), np.uint8)dilate_1 = cv2.dilate(pie, kernel, iterations=1)dilate_2 = cv2.dilate(pie, kernel, iterations=2)dilate_3 = cv2.dilate(pie, kernel, iterations=3)res = np.hstack((dilate_1, dilate_2, dilate_3))cv2.imshow('res', res)cv2.waitKey(0)cv2.destroyAllWindows()
膨胀圆3次的结果展示,图7:
二、 开运算与闭运算
2.1 开运算
# 开:先腐蚀,再膨胀img = cv2.imread('DataPreprocessing/img/dige.png')kernel = np.ones((5, 5), np.uint8)opening = cv2.morphologyEx(img, cv2.MORPH_OPEN, kernel)cv2.imshow('opening', opening)cv2.waitKey(0)cv2.destroyAllWindows()
将原图1,先腐蚀,再膨胀,得到开运算结果图8:
2.2 闭运算
# 闭:先膨胀,再腐蚀img = cv2.imread('DataPreprocessing/img/dige.png')kernel = np.ones((5, 5), np.uint8)closing = cv2.morphologyEx(img, cv2.MORPH_CLOSE, kernel)cv2.imshow('closing', closing)cv2.waitKey(0)cv2.destroyAllWindows()
将原图1,先膨胀,再腐蚀,得到开运算结果图9:
三、梯度运算
拿原图3的圆,做5次膨胀,5次腐蚀,相减得到其轮廓。
# 梯度=膨胀-腐蚀pie = cv2.imread('DataPreprocessing/img/pie.png')kernel = np.ones((7, 7), np.uint8)dilate = cv2.dilate(pie, kernel, iterations=5)erosion = cv2.erode(pie, kernel, iterations=5)res = np.hstack((dilate, erosion))cv2.imshow('res', res)cv2.waitKey(0)cv2.destroyAllWindows()gradient = cv2.morphologyEx(pie, cv2.MORPH_GRADIENT, kernel)cv2.imshow('gradient', gradient)cv2.waitKey(0)cv2.destroyAllWindows()
得到梯度运算结果图10:
四、礼帽与黑帽
4.1 礼帽
礼帽 = 原始输入-开运算结果
# 礼帽img = cv2.imread('DataPreprocessing/img/dige.png')tophat = cv2.morphologyEx(img, cv2.MORPH_TOPHAT, kernel)cv2.imshow('tophat', tophat)cv2.waitKey(0)cv2.destroyAllWindows()
得到礼帽结果图11:
4.2 黑帽
黑帽 = 闭运算-原始输入
# 黑帽img = cv2.imread('DataPreprocessing/img/dige.png')blackhat = cv2.morphologyEx(img, cv2.MORPH_BLACKHAT, kernel)cv2.imshow('blackhat ', blackhat)cv2.waitKey(0)cv2.destroyAllWindows()
得到礼帽结果图12: