以下是实现代码：

import numpy as np import cv2

def RGB_to_HSI(img): # 将RGB图像转换为HSI图像 bgr = img / 255.0 b = bgr[:,:,0] g = bgr[:,:,1] r = bgr[:,:,2] num = 0.5 * ((r-g)+(r-b)) den = np.sqrt((r-g)**2 + (r-b)(g-b)) theta = np.arccos(num/(den + 1e-5)) H = np.zeros_like(theta) H[b<=g] = theta[b<=g] H[b>g] = 2np.pi - theta[b>g] H /= 2np.pi S = 1 - 3np.minimum(np.minimum(r,g),b)/(r+g+b+1e-5) I = (r+g+b) / 3.0 HSI = np.zeros_like(bgr) HSI[:,:,0] = H HSI[:,:,1] = S HSI[:,:,2] = I return HSI

def HSI_to_RGB(img): # 将HSI图像转换为RGB图像 H = img[:,:,0] * 2np.pi S = img[:,:,1] I = img[:,:,2] R = np.zeros_like(H) G = np.zeros_like(H) B = np.zeros_like(H) # RG sector (0 <= H < 2pi/3) idx = np.logical_and(H>=0, H<2np.pi/3) B[idx] = I[idx] * (1-S[idx]) R[idx] = I[idx] * (1 + S[idx]np.cos(H[idx])/np.cos(np.pi/3-H[idx])) G[idx] = 3I[idx] - (R[idx] + B[idx]) # BG sector (2pi/3 <= H < 4pi/3) idx = np.logical_and(H>=2np.pi/3, H<4np.pi/3) R[idx] = I[idx] * (1-S[idx]) G[idx] = I[idx] * (1 + S[idx]np.cos(H[idx]-2np.pi/3)/np.cos(np.pi/3-(H[idx]-2np.pi/3))) B[idx] = 3I[idx] - (R[idx] + G[idx]) # BR sector (4pi/3 <= H < 2pi) idx = np.logical_and(H>=4np.pi/3, H<2np.pi) G[idx] = I[idx] * (1-S[idx]) B[idx] = I[idx] * (1 + S[idx]np.cos(H[idx]-4np.pi/3)/np.cos(np.pi/3-(H[idx]-4np.pi/3))) R[idx] = 3I[idx] - (G[idx] + B[idx]) RGB = np.zeros_like(img) RGB[:,:,0] = R RGB[:,:,1] = G RGB[:,:,2] = B return (RGB255).astype(np.uint8)

导入彩色图像

img = cv2.imread('test.jpg')

RGB->HSI

hsi = RGB_to_HSI(img) hsi_img = cv2.cvtColor((hsi*255).astype(np.uint8), cv2.COLOR_HSV2BGR)

HSI->RGB

rgb = HSI_to_RGB(hsi) rgb_img = cv2.cvtColor(rgb, cv2.COLOR_BGR2RGB)

显示图像

cv2.namedWindow('RGB->HSI->RGB', cv2.WINDOW_NORMAL) cv2.resizeWindow('RGB->HSI->RGB', 900, 300) cv2.imshow('RGB->HSI->RGB', np.hstack((img, hsi_img, rgb_img))) cv2.waitKey(0) cv2.destroyAllWindows(