基于OpenCV的python的二值化处理 cv2.threshold()

兄弟们，实验代码的python版本就在这了，欢迎继续改

简单阈值处理 cv2.threshold()
所谓阈值处理，就是给定一个阈值，当像素值比指定阈值大或小时做相关的操作。这个字念yu，不是fa，方法签名为:cv2.threshold(src,thresh,maxval,type,dst=None),需要将的是OpenCV中提供的几种type：

cv2.THRESH_BINARY：若像素值大于阈值，则置为maxval；否则置0
cv2.THRESH_BINARY_INV：THRESH_BINARY的反转
cv2.THRESH_TRUNC：若像素值大于阈值，则置为阈值；否则不变
cv2.THRESH_TOZERO：小于阈值的部分置为0；其他不变
cv2.THRESH_TOZERO_INV：THRESH_TOZERO的反转
 

import cv2
import numpy as np

'''
用滑动条控制阈值处理（控制其类型和阈值）
按键操作说明：
1、键盘按键【Esc】-退出程序
2、滑动条模式0--二进制阈值
3、滑动条模式1--反二进制阈值
4、滑动条模式2--截断阈值
5、滑动条模式3--反阈值化为0
6、滑动条模式4--阈值化为0
'''
path_of_src = "E:/pycharm_work/2021_10_14/threshold/2.tif"

min_threshold = 0
max_threshold = 255
switch = "0--1--2--3--4"


def load_image(path):
    src = cv2.imread(path,0)
    # cv2.imshow("src",src)
    # cv2.imwrite("./threshold/2.jpg", src)
    # cv2.waitKey(0)
    # cv2.destroyAllWindows()
    return src

def threshold(src,threshold_value,flag):

    '''
    2、滑动条模式0--二进制阈值
    3、滑动条模式1--反二进制阈值
    4、滑动条模式2--截断阈值
    5、滑动条模式3--反阈值化为0
    6、滑动条模式4--阈值化为0
    '''
    if flag == 0:
       _,dst = cv2.threshold(src,threshold_value,255,0)
    elif flag == 1:
       _,dst = cv2.threshold(src,threshold_value,255,1)
    elif flag == 2:
       _,dst = cv2.threshold(src,threshold_value,255,2)
    elif flag == 3:
       _,dst = cv2.threshold(src,threshold_value,255,3)
    else:
       _,dst = cv2.threshold(src,threshold_value,255,4)
    return dst

def nothing(pos):
    pass



if __name__ == "__main__":
    #loading the original picture
    src = load_image(path_of_src)
    #create one Window
    cv2.namedWindow("THRESHOLD_WINDOW",0)
    cv2.resizeWindow("THRESHOLD_WINDOW", 1000,600)
    #cv2.imshow("src",src)
    #create one Trackbar
    #参数1：滑动条返回值 参数2：对应窗口 参数3：最小值 参数4：最大值  参数5：为了解决createTrackbar只能返回一个滑动条的问题
    cv2.createTrackbar("The threshold value","THRESHOLD_WINDOW",min_threshold,max_threshold,nothing)
    cv2.createTrackbar(switch,"THRESHOLD_WINDOW",0,4,nothing)
    print("1、键盘按键【Esc】-退出程序,2、滑动条模式0--二进制阈值,3、滑动条模式1--反二进制阈值,4、滑动条模式2--截断阈值,5、滑动条模式3--反阈值化为0,6、滑动条模式4--阈值化为0")
    while True:
        value_of_threshold = cv2.getTrackbarPos("The threshold value","THRESHOLD_WINDOW")
        flag = cv2.getTrackbarPos(switch,"THRESHOLD_WINDOW")
        dst  = threshold(src,value_of_threshold,flag)
        cv2.imshow("THRESHOLD_WINDOW",dst)
        if cv2.waitKey(1)& 0xFF == 27:
            break
            pass