Python-opencv學習 5 閾值分割

threshold()

retval,dst=cv2.threshold(src,thresh,maxval,type)

• retval，閾值
• dst，處理結果
• src，原圖像
• thresh，閾值
• maxval，最大值
• type，類型

閾值方法

• cv2.THRESH_BINARY
• cv2.THRESH_BINARY_INV
• cv2.THRESH_TRUNC
• cv2.THRESH_TOZERO
• cv2.THRESH_TOZERO_INV

閾值方法實例

import cv2
a=cv2.imread("C:\\Users\\Chester\\Downloads\\opencv-python_simpletest\\image\\lena512.bmp",cv2.IMREAD_UNCHANGED)
#注意原始圖像的類型，必須是8位單通道圖像,彩色圖像無意義
r,b1=cv2.threshold(a,127,255,cv2.THRESH_BINARY)
r,b2=cv2.threshold(a,127,255,cv2.THRESH_BINARY_INV)
r,b3=cv2.threshold(a,127,255,cv2.THRESH_TRUNC )
r,b4=cv2.threshold(a,127,255,cv2.THRESH_TOZERO )
r,b5=cv2.threshold(a,127,255,cv2.THRESH_TOZERO_INV)
cv2.imshow("original",a)
cv2.imshow("THRESH_BINARY",b1)
cv2.imshow("THRESH_BINARY_INV",b1)
cv2.imshow("THRESH_TRUNC",b1)
cv2.imshow("THRESH_TOZERO",b1)
cv2.imshow("THRESH_TOZERO_INV",b1)

print(r)
cv2.waitKey()
cv2.destroyAllWindows()