最新国产好看的视频,伊人天堂AV在线,国产Aaaaaa视频,蜜臀视频在线观看一区,人妻av色图,密臀久久久精品影片,青青视频免费观看毛片,久草在线观看视,国产三级精品色情在线

Python+OpenCV實(shí)現(xiàn)閾值分割的方法詳解

 更新時(shí)間:2022年05月16日 14:27:04   作者:用余生去守護(hù)  
閾值分割法是一種基于區(qū)域的圖像分割技術(shù),原理是把圖像像素點(diǎn)分為若干類。本文將利用Python+OpenCV實(shí)現(xiàn)閾值分割,感興趣的可以了解一下

一、全局閾值

原圖:

整幅圖采用一個(gè)閾值,與圖片的每一個(gè)像素灰度進(jìn)行比較,重新賦值;

1.效果圖

2.源碼

import cv2
import matplotlib.pyplot as plt
#設(shè)定閾值
thresh=130
#載入原圖,并轉(zhuǎn)化為灰度圖像
img_original=cv2.imread(r'E:\py\python3.7\test2\test14yuzhi\cell.png',0)
img_original=cv2.resize(img_original,(0,0),fx=0.3,fy=0.3)
#采用5種閾值類型(thresholding type)分割圖像
retval1,img_binary=cv2.threshold(img_original,thresh,255,cv2.THRESH_BINARY)
retval2,img_binary_invertion=cv2.threshold(img_original,thresh,255,cv2.THRESH_BINARY_INV)
retval3,img_trunc=cv2.threshold(img_original,thresh,255,cv2.THRESH_TRUNC)
retval4,img_tozero=cv2.threshold(img_original,thresh,255,cv2.THRESH_TOZERO)
retval5,img_tozero_inversion=cv2.threshold(img_original,thresh,255,cv2.THRESH_TOZERO_INV)
#采用plt.imshow()顯示圖像
imgs=[img_original,img_binary,img_binary_invertion,img_trunc,img_tozero,img_tozero_inversion]
titles=['original','binary','binary_inv','trunc','tozero','tozero_inv']
for i in range(6):
    plt.subplot(2,3,i+1)
    plt.imshow(imgs[i],'gray')
    plt.title(titles[i])
    plt.xticks([])
    plt.yticks([])
plt.show()

二、滑動(dòng)改變閾值(滑動(dòng)條)

1.效果圖

2.源碼

代碼如下(示例):

import cv2
import numpy as np
import matplotlib.pyplot as plt
#載入原圖,轉(zhuǎn)化為灰度圖像,并通過(guò)cv2.resize()等比調(diào)整圖像大小
img_original=cv2.imread(r'E:\py\python3.7\test2\test14yuzhi\cell.png',0)
img_original=cv2.resize(img_original,(0,0),fx=0.3,fy=0.3)
#初始化閾值,定義全局變量imgs
thresh=130
imgs=0
#創(chuàng)建滑動(dòng)條回調(diào)函數(shù),參數(shù)thresh為滑動(dòng)條對(duì)應(yīng)位置的數(shù)值
def threshold_segmentation(thresh):
    #采用5種閾值類型(thresholding type)分割圖像
    retval1,img_binary=cv2.threshold(img_original,thresh,255,cv2.THRESH_BINARY)
    retval2,img_binary_invertion=cv2.threshold(img_original,thresh,255,cv2.THRESH_BINARY_INV)
    retval3,img_trunc=cv2.threshold(img_original,thresh,255,cv2.THRESH_TRUNC)
    retval4,img_tozero=cv2.threshold(img_original,thresh,255,cv2.THRESH_TOZERO)
    retval5,img_tozero_inversion=cv2.threshold(img_original,thresh,255,cv2.THRESH_TOZERO_INV)
    #由于cv2.imshow()顯示的是多維數(shù)組(ndarray),因此我們通過(guò)np.hstack(數(shù)組水平拼接)
    #和np.vstack(豎直拼接)拼接數(shù)組,達(dá)到同時(shí)顯示多幅圖的目的
    img1=np.hstack([img_original,img_binary,img_binary_invertion])
    img2=np.hstack([img_trunc,img_tozero,img_tozero_inversion])
    global imgs
    imgs=np.vstack([img1,img2])
#新建窗口
cv2.namedWindow('Images')
#新建滑動(dòng)條,初始位置為130
cv2.createTrackbar('threshold value','Images',130,255,threshold_segmentation)
#第一次調(diào)用函數(shù)
threshold_segmentation(thresh)
#顯示圖像
while(1):
    cv2.imshow('Images',imgs)
    if cv2.waitKey(1)==ord('q'):
        break
cv2.destroyAllWindows()

三、自適應(yīng)閾值分割

1.效果圖

2.源碼

代碼如下(示例):

import cv2
import matplotlib.pyplot as plt
#載入原圖
img_original=cv2.imread(r'E:\py\python3.7\test2\test14yuzhi\cell.png',0)
#全局閾值分割
retval,img_global=cv2.threshold(img_original,130,255,cv2.THRESH_BINARY)
#自適應(yīng)閾值分割
img_ada_mean=cv2.adaptiveThreshold(img_original,255,cv2.ADAPTIVE_THRESH_MEAN_C,cv2.THRESH_BINARY,15,3)
img_ada_gaussian=cv2.adaptiveThreshold(img_original,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C,cv2.THRESH_BINARY,15,3)
imgs=[img_original,img_global,img_ada_mean,img_ada_gaussian]
titles=['Original Image','Global Thresholding(130)','Adaptive Mean','Adaptive Guassian',]
#顯示圖片
for i in range(4):
    plt.subplot(2,2,i+1)
    plt.imshow(imgs[i],'gray')
    plt.title(titles[i])
    plt.xticks([])
    plt.yticks([])
plt.show()

3.GaussianBlur()函數(shù)去噪

代碼如下(示例):

import cv2
import matplotlib.pyplot as plt
#載入原圖
img_original=cv2.imread(r'E:\py\python3.7\test2\test14yuzhi\cell.png',0)
#高斯濾波
img_blur=cv2.GaussianBlur(img_original,(13,13),13)  #根據(jù)情況修改參數(shù)
#自適應(yīng)閾值分割
img_thresh=cv2.adaptiveThreshold(img_original,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C,cv2.THRESH_BINARY,15,3)
img_thresh_blur=cv2.adaptiveThreshold(img_blur,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C,cv2.THRESH_BINARY,15,3)
#顯示圖像
imgs=[img_thresh,img_thresh_blur]
titles=['img_thresh','img_thresh_blur']
for i in range(2):
    plt.subplot(1,2,i+1)
    plt.imshow(imgs[i],'gray')
    plt.title(titles[i])
    plt.xticks([])
    plt.yticks([])
plt.show()

四、參數(shù)解釋

1.cv2.threshold(src, thresh, maxval, type)

參數(shù):

src:輸入的圖像

thresh:圖像分割所用的閾值(threshold value)

maxval:當(dāng)閾值類型(thresholding type)采用cv2.THRESH_BINARY和cv2.THRESH_BINARY_INV時(shí)像素點(diǎn)被賦予的新值

type:介紹6種類型:

cv2.THRESH_BINARY(當(dāng)圖像某點(diǎn)像素值大于thresh(閾值)時(shí)賦予maxval,反之為0。注:最常用)

cv2.THRESH_BINARY_INV(當(dāng)圖像某點(diǎn)像素值小于thresh時(shí)賦予maxval,反之為0)

cv2.THRESH_TRUNC(當(dāng)圖像某點(diǎn)像素值大于thresh時(shí)賦予thresh,反之不變。注:雖然maxval沒(méi)用了,但是調(diào)用函數(shù)不能省略)

cv2.THRESH_TOZERO(當(dāng)圖像某點(diǎn)像素值小于thresh時(shí)賦予0,反之不變。注:同上)

cv2.THRESH_TOZERO_INV(當(dāng)圖像某點(diǎn)像素值大于thresh時(shí)賦予0,反之不變。注:同上)

cv2.THRESH_OTSU(該方法自動(dòng)尋找最優(yōu)閾值,并返回給retval,見(jiàn)下文)

返回值:

retval:設(shè)定的thresh值,或者是通過(guò)cv2.THRESH_OTSU算出的最優(yōu)閾值

dst:閾值分割后的圖像

以上就是Python+OpenCV實(shí)現(xiàn)閾值分割的方法詳解的詳細(xì)內(nèi)容,更多關(guān)于Python OpenCV閾值分割的資料請(qǐng)關(guān)注腳本之家其它相關(guān)文章!

相關(guān)文章

最新評(píng)論

昂仁县| 阳春市| 华宁县| 光泽县| 普兰店市| 长葛市| 临城县| 浦城县| 永登县| 拉孜县| 蚌埠市| 蕲春县| 时尚| 和田市| 探索| 云林县| 共和县| 霍山县| 孝感市| 庄河市| 含山县| 渑池县| 浪卡子县| 郯城县| 新宾| 阿荣旗| 夹江县| 利辛县| 德令哈市| 府谷县| 弋阳县| 泸西县| 长海县| 六盘水市| 正定县| 乃东县| 乌苏市| 龙南县| 黄浦区| 庆元县| 云南省|