算法中,初始種子可自動選擇(通過不同的劃分可以得到不同的種子,可按照自己需要改進算法),圖分別為原圖(自己畫了兩筆為了分割成不同區域)、灰度圖直方圖、初始種子圖、區域生長結果圖。
另外,不管時初始種子選擇還是區域生長,閾值選擇很重要。
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import cv2 import numpy as np import matplotlib.pyplot as plt #初始種子選擇 def originalSeed(gray, th): ret, thresh = cv2.cv2.threshold(gray, th, 255 , cv2.THRESH_BINARY) #二值圖,種子區域(不同劃分可獲得不同種子) kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE, ( 3 , 3 )) #3×3結構元 thresh_copy = thresh.copy() #復制thresh_A到thresh_copy thresh_B = np.zeros(gray.shape, np.uint8) #thresh_B大小與A相同,像素值為0 seeds = [ ] #為了記錄種子坐標 #循環,直到thresh_copy中的像素值全部為0 while thresh_copy. any (): Xa_copy, Ya_copy = np.where(thresh_copy > 0 ) #thresh_A_copy中值為255的像素的坐標 thresh_B[Xa_copy[ 0 ], Ya_copy[ 0 ]] = 255 #選取第一個點,并將thresh_B中對應像素值改為255 #連通分量算法,先對thresh_B進行膨脹,再和thresh執行and操作(取交集) for i in range ( 200 ): dilation_B = cv2.dilate(thresh_B, kernel, iterations = 1 ) thresh_B = cv2.bitwise_and(thresh, dilation_B) #取thresh_B值為255的像素坐標,并將thresh_copy中對應坐標像素值變為0 Xb, Yb = np.where(thresh_B > 0 ) thresh_copy[Xb, Yb] = 0 #循環,在thresh_B中只有一個像素點時停止 while str (thresh_B.tolist()).count( "255" ) > 1 : thresh_B = cv2.erode(thresh_B, kernel, iterations = 1 ) #腐蝕操作 X_seed, Y_seed = np.where(thresh_B > 0 ) #取處種子坐標 if X_seed.size > 0 and Y_seed.size > 0 : seeds.append((X_seed[ 0 ], Y_seed[ 0 ])) #將種子坐標寫入seeds thresh_B[Xb, Yb] = 0 #將thresh_B像素值置零 return seeds #區域生長 def regionGrow(gray, seeds, thresh, p): seedMark = np.zeros(gray.shape) #八鄰域 if p = = 8 : connection = [( - 1 , - 1 ), ( - 1 , 0 ), ( - 1 , 1 ), ( 0 , 1 ), ( 1 , 1 ), ( 1 , 0 ), ( 1 , - 1 ), ( 0 , - 1 )] elif p = = 4 : connection = [( - 1 , 0 ), ( 0 , 1 ), ( 1 , 0 ), ( 0 , - 1 )] #seeds內無元素時候生長停止 while len (seeds) ! = 0 : #棧頂元素出棧 pt = seeds.pop( 0 ) for i in range (p): tmpX = pt[ 0 ] + connection[i][ 0 ] tmpY = pt[ 1 ] + connection[i][ 1 ] #檢測邊界點 if tmpX < 0 or tmpY < 0 or tmpX > = gray.shape[ 0 ] or tmpY > = gray.shape[ 1 ]: continue if abs ( int (gray[tmpX, tmpY]) - int (gray[pt])) < thresh and seedMark[tmpX, tmpY] = = 0 : seedMark[tmpX, tmpY] = 255 seeds.append((tmpX, tmpY)) return seedMark path = "_rg.jpg" img = cv2.imread(path) gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) #hist = cv2.calcHist([gray], [0], None, [256], [0,256])#直方圖 seeds = originalSeed(gray, th = 253 ) seedMark = regionGrow(gray, seeds, thresh = 3 , p = 8 ) #plt.plot(hist) #plt.xlim([0, 256]) #plt.show() cv2.imshow( "seedMark" , seedMark) cv2.waitKey( 0 ) |
以上這篇關于初始種子自動選取的區域生長實例(python+opencv)就是小編分享給大家的全部內容了,希望能給大家一個參考,也希望大家多多支持服務器之家。
原文鏈接:https://www.cnblogs.com/er-gou-zi/p/12016951.html