"""
Author:XiaoMa
date:2021/10/24
"""
#調(diào)用需要的包
import cv2
import matplotlib.pyplot as plt
 
img0 = cv2.imread('E:\From Zhihu\For the desk\cvseven.jpeg')
img1 = cv2.cvtColor(img0, cv2.COLOR_BGR2GRAY)     #轉(zhuǎn)化為灰度圖
h, w = img1.shape[:2]
print(h, w)
cv2.namedWindow("W0")
cv2.imshow("W0", img1)
cv2.waitKey(delay = 0)

#繪制直方圖
hist = cv2.calcHist([img1], [0], None, [256], [0, 255])
plt.plot(hist, color = 'lime', label = '直方圖', linestyle = '--')
plt.legend()
plt.savefig('E:\From Zhihu\For the desk\cvseven1.jpeg')
plt.show()

"""
Author:XiaoMa
date:2021/10/24
"""
#調(diào)用需要的包
import cv2
import matplotlib.pyplot as plt
 
plt.rcParams['font.family'] = 'SimHei'       #將全局中文字體改為黑體
 
img0 = cv2.imread('E:\From Zhihu\For the desk\cvseven.jpeg')
img1 = cv2.cvtColor(img0, cv2.COLOR_BGR2GRAY)
h, w = img1.shape[:2]
print(h, w)
cv2.namedWindow("W0")
cv2.imshow("W0", img0)
cv2.waitKey(delay = 0)
 
#繪制直方圖
hist = cv2.calcHist([img0], [0], None, [256], [0, 255])
plt.plot(hist, color = 'lime', label = '藍(lán)色通道直方圖', linestyle = '--', alpha = 1)
plt.legend()
plt.savefig('E:\From Zhihu\For the desk\cvseven1.jpeg')
plt.show()

##得到掩膜圖
mask = np.zeros(img0.shape, np.uint8)    #將每一個(gè)像素點(diǎn)設(shè)置為0，就是黑色
mask[109:309, 212:412] = 255             #選取特定區(qū)域設(shè)置為白色
img0_1 = cv2.bitwise_and(img0, mask)     #圖像與操作得到掩膜圖
cv2.namedWindow("W1")
cv2.imshow("W1", img0_1)
cv2.waitKey(delay = 0)

#繪制掩膜直方圖
##得到掩膜圖
mask = np.zeros(img1.shape, np.uint8)    #將每一個(gè)像素點(diǎn)設(shè)置為0，就是黑色
mask[109:309, 212:412] = 255             #選取特定區(qū)域設(shè)置為白色
img1_1 = cv2.bitwise_and(img1, mask)     #圖像與操作得到掩膜圖
cv2.namedWindow("W1")
cv2.imshow("W1", img1_1)
cv2.waitKey(delay = 0)
##繪制掩膜直方圖和部分圖像直方圖
hist1 = cv2.calcHist([img1], [0], mask, [256], [0, 255])         #掩膜圖直方圖，參數(shù)需要修改
hist2 = cv2.calcHist([img1], [0], None, [256], [0,255])
plt.plot(hist1, color = 'b', label = '掩膜直方圖', linestyle = '--')
plt.plot(hist2, color = 'r', label = '原圖直方圖', linestyle = '-.')
plt.legend()
plt.savefig('E:\From Zhihu\For the desk\cvseven2.jpeg')
plt.show()

img0_2 = cv2.cvtColor(img0, cv2.COLOR_BGR2HSV) #將 RGB 空間轉(zhuǎn)化為 HSV 空間
cv2.namedWindow("W2")
cv2.imshow("W2", img0_2)
cv2.waitKey(delay = 0)

##繪制H-S直方圖
hist3 = cv2.calcHist ([img0_2], [0, 1], None , [180, 256], [0, 180, 0, 256])#官網(wǎng)給出的解釋：channel = [0,1] 因?yàn)槲覀冃枰瑫r(shí)處理 H 和 S 平面；bins = [180,256] H 平面為 180，S 平面為 256；range = [0,180,0,256] 色調(diào)值介于 0 和 180 之間，飽和度介于 0 和 256 之間
plt.imshow(hist3)
plt.savefig('E:\From Zhihu\For the desk\cvseven3.jpeg')
plt.show()