色彩空间的转换

颜色空间转换, 从bgr到hsv
hsv_image = cv.cvtColor(image, cv.COLOR_BGR2HSV)

用inRange函数提取指定颜色范围,其余置为(0)黑,这里对hsv来处理
mask = cv.inRange(hsv_image, lowerb=lower_hsv, upperb=upper_hsv)

import cv2 as cv
import numpy as np


# 颜色空间转换, 从bgr到gray, hsv, yuv, ycrcb
def color_space_convert(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)

# bgr 转 hsv
def bgr_convert_hsv():
    print("请输入blue, green, red : ", end='')
    blue, green, red = map(int, input().split())
    color = np.array([[[blue, green, red]]], dtype=np.uint8)
    hsv_color = cv.cvtColor(color, cv.COLOR_BGR2HSV)

    hue = hsv_color[0][0][0]
    print("Lower bound is :"),
    print("[" + str(hue - 10) + ", 100, 100]\n")

    print("Upper bound is :"),
    print("[" + str(hue + 10) + ", 255, 255]")


# 从视频中提取指定颜色范围，并将其置为白，其余置为黑
def extract_object_demo():
    capture = cv.VideoCapture("./images/3.mp4")
    while True:
        ret, frame = capture.read()

        if not ret:
            break

        hsv = cv.cvtColor(frame, cv.COLOR_BGR2HSV)
        lower_hsv = np.array([37, 43, 46])
        upper_hsv = np.array([77, 255, 255])

        # 用inRange函数提取指定颜色范围,其余置为(0)黑,这里对hsv来处理
        mask = cv.inRange(hsv, lowerb=lower_hsv, upperb=upper_hsv)
        cv.imshow("video", frame)
        cv.imshow("mask", mask)

        c = cv.waitKey(40)
        if c == 27:
            break

# 对图片三个通道颜色提取并放在三张图片中
def channel_split_merge(image):
    b, g, r = cv.split(image)
    # print(b.shape)  -->  (1334, 750)
    cv.imshow("blue", b)
    cv.imshow("green", g)
    cv.imshow("red", r)

    changed_image = image.copy()
    changed_image[:, :, 2] = 0  # 将r通道颜色全部置为0
    cv.imshow("changed_image", changed_image)

    merge_image = cv.merge([b, g, r])
    cv.imshow("merge_image", merge_image)

if __name__ == "__main__":

    image = cv.imread("./images/CrystalLiu1.jpg")
    cv.namedWindow("image", cv.WINDOW_AUTOSIZE)
    cv.imshow("image", image)

    bgr_convert_hsv()

    # channel_split_merge(image)
    # color_space_convert(image)
    # extract_object_demo()

    cv.waitKey(0)
    cv.destroyAllWindows()

bgr_convert_hsv()

channel_split_merge(image)

color_space_convert(image)

extract_object_demo()