pyhton3 + opencv HSV色彩空間特定顏色提取 inRange函數使用實例

pyhton3 + opencv 

HSV色彩空間特定顏色提取  inRange函數使用實例

代碼如下：

import cv2 as cv
import numpy as np

def extrace_object_demo():
    capture = cv.VideoCapture(0)
    while(True):
        ret, frame = capture.read()
        if ret == False:
            break;
        hsv = cv.cvtColor(frame, cv.COLOR_BGR2HSV)
        lower_hsv = np.array([35, 43, 46])
        upper_hsv = np.array([77, 255, 255])
        mask = cv.inRange(hsv, lowerb=lower_hsv, upperb=upper_hsv)
        dst = cv.bitwise_and(frame, frame, mask=mask)
        cv.imshow("video", frame)
        cv.imshow("mask", dst)
        c = cv.waitKey(40)
        if c == 27:
            break

def extrace_object_demo2():
	src = cv.imread("E:/opencv/sources/samples/data/opencv-logo.png")
	hsv = cv.cvtColor(src, cv.COLOR_BGR2HSV)
	lower_hsv = np.array([35, 43, 46])
	upper_hsv = np.array([77, 255, 255])
	mask = cv.inRange(hsv, lowerb=lower_hsv, upperb=upper_hsv)
	dst = cv.bitwise_and(src, src, mask=mask)
	cv.imshow("video", src)
	cv.imshow("mask", dst)
	cv.waitKey(40)
    

def color_space_demo(image):
    gray = cv.cvtColor(image, cv.COLOR_BGR2GRAY)
    cv.imshow("gray", gray)
    hsv = cv.cvtColor(image, cv.COLOR_BGR2HSV)
    cv.imshow("hsv", hsv)
    yuv = cv.cvtColor(image, cv.COLOR_BGR2YUV)
    cv.imshow("yuv", yuv)
    Ycrcb = cv.cvtColor(image, cv.COLOR_BGR2YCrCb)
    cv.imshow("ycrcb", Ycrcb)

print("--------- Hello Python ---------")

extrace_object_demo2()


cv.waitKey(0)
cv.destroyAllWindows()

extrace_object_demo()函數是基於攝像頭綠色實時提取

extrace_object_demo2()是基於圖片綠色提取

執行extrace_object_demo()如圖：

可以根據第一張圖表格內容提取特定顏色

只需修改lower_hsv與upper_hsv的值就可以

lower_hsv = np.array([35, 43, 46])
upper_hsv = np.array([77, 255, 255])

通過這個技巧的學習，我們在以後應用中會方便很多

本試驗應用圖片源於OpenCV自帶的地址如下：

opencv/sources/samples/data/opencv-logo.png

注：儘量背景位白色進行試驗，效果會更好