https://blog.csdn.net/weixin_38570251/article/details/82079080

threshold：固定閾值二值化，

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

src： 輸入圖，只能輸入單通道圖像，通常來(lái)說(shuō)為灰度圖

dst： 輸出圖

thresh： 閾值

maxval： 當(dāng)像素值超過(guò)了閾值（或者小于閾值，根據(jù)type來(lái)決定），所賦予的值

type：二值化操作的類型，包含以下5種類型： cv2.THRESH_BINARY； cv2.THRESH_BINARY_INV； cv2.THRESH_TRUNC； cv2.THRESH_TOZERO；cv2.THRESH_TOZERO_INV

官方文檔的示例代碼：

importcv2

importnumpyasnp

frommatplotlibimportpyplotasplt

img = cv2.imread('gradient.png',0)

ret,thresh1 = cv2.threshold(img,127,255,cv2.THRESH_BINARY)

ret,thresh2 = cv2.threshold(img,127,255,cv2.THRESH_BINARY_INV)

ret,thresh3 = cv2.threshold(img,127,255,cv2.THRESH_TRUNC)

ret,thresh4 = cv2.threshold(img,127,255,cv2.THRESH_TOZERO)

ret,thresh5 = cv2.threshold(img,127,255,cv2.THRESH_TOZERO_INV)

titles = ['Original Image','BINARY','BINARY_INV','TRUNC','TOZERO','TOZERO_INV']

images = [img, thresh1, thresh2, thresh3, thresh4, thresh5]

foriinxrange(6):

plt.subplot(2,3,i+1),plt.imshow(images[i],'gray')

? ? plt.title(titles[i])

? ? plt.xticks([]),plt.yticks([])

plt.show()