Python实现RGB与HSI颜色空间的互换

时间:2025-01-31 15:44:37
#!/usr/bin/env python # -*- coding: utf-8 -*- # @Time : 2017/10/14 13:21 # @Author : DaiPuWei # @Site : 理学院机房 # @File : __init__. # @Software: PyCharm Community Edition import cv2 import numpy as np def RGB2HSI(rgb_img): """ 这是将RGB彩色图像转化为HSI图像的函数 :param rgm_img: RGB彩色图像 :return: HSI图像 """ #保存原始图像的行列数 row = (rgb_img)[0] col = (rgb_img)[1] #对原始图像进行复制 hsi_img = rgb_img.copy() #对图像进行通道拆分 B,G,R = (rgb_img) #把通道归一化到[0,1] [B,G,R] = [ i/ 255.0 for i in ([B,G,R])] H = ((row, col)) #定义H通道 I = (R + G + B) / 3.0 #计算I通道 S = ((row,col)) #定义S通道 for i in range(row): den = ((R[i]-G[i])**2+(R[i]-B[i])*(G[i]-B[i])) thetha = (0.5*(R[i]-B[i]+R[i]-G[i])/den) #计算夹角 h = (col) #定义临时数组 #den>0且G>=B的元素h赋值为thetha h[B[i]<=G[i]] = thetha[B[i]<=G[i]] #den>0且G<=B的元素h赋值为thetha h[G[i]<B[i]] = 2*-thetha[G[i]<B[i]] #den<0的元素h赋值为0 h[den == 0] = 0 H[i] = h/(2*) #弧度化后赋值给H通道 #计算S通道 for i in range(row): min = [] #找出每组RGB值的最小值 for j in range(col): arr = [B[i][j],G[i][j],R[i][j]] ((arr)) min = (min) #计算S通道 S[i] = 1 - min*3/(R[i]+B[i]+G[i]) #I为0的值直接赋值0 S[i][R[i]+B[i]+G[i] == 0] = 0 #扩充到255以方便显示,一般H分量在[0,2pi]之间,S和I在[0,1]之间 hsi_img[:,:,0] = H*255 hsi_img[:,:,1] = S*255 hsi_img[:,:,2] = I*255 return hsi_img def HSI2RGB(hsi_img): """ 这是将HSI图像转化为RGB图像的函数 :param hsi_img: HSI彩色图像 :return: RGB图像 """ # 保存原始图像的行列数 row = (hsi_img)[0] col = (hsi_img)[1] #对原始图像进行复制 rgb_img = hsi_img.copy() #对图像进行通道拆分 H,S,I = (hsi_img) #把通道归一化到[0,1] [H,S,I] = [ i/ 255.0 for i in ([H,S,I])] R,G,B = H,S,I for i in range(row): h = H[i]*2* #H大于等于0小于120度时 a1 = h >=0 a2 = h < 2*/3 a = a1 & a2 #第一种情况的花式索引 tmp = ( / 3 - h) b = I[i] * (1 - S[i]) r = I[i]*(1+S[i]*(h)/tmp) g = 3*I[i]-r-b B[i][a] = b[a] R[i][a] = r[a] G[i][a] = g[a] #H大于等于120度小于240度 a1 = h >= 2*/3 a2 = h < 4*/3 a = a1 & a2 #第二种情况的花式索引 tmp = ( - h) r = I[i] * (1 - S[i]) g = I[i]*(1+S[i]*(h-2*/3)/tmp) b = 3 * I[i] - r - g R[i][a] = r[a] G[i][a] = g[a] B[i][a] = b[a] #H大于等于240度小于360度 a1 = h >= 4 * / 3 a2 = h < 2 * a = a1 & a2 #第三种情况的花式索引 tmp = (5 * / 3 - h) g = I[i] * (1-S[i]) b = I[i]*(1+S[i]*(h-4*/3)/tmp) r = 3 * I[i] - g - b B[i][a] = b[a] G[i][a] = g[a] R[i][a] = r[a] rgb_img[:,:,0] = B*255 rgb_img[:,:,1] = G*255 rgb_img[:,:,2] = R*255 return rgb_img def run_main(): """ 这是主函数 """ #利用opencv读入图片 rgb_img = ('',cv2.IMREAD_COLOR) #进行颜色空间转换 hsi_img = RGB2HSI(rgb_img) rgb_img2 = HSI2RGB(hsi_img) #opencv库的颜色空间转换结果 hsi_img2 = (rgb_img,cv2.COLOR_BGR2HSV) rgb_img3 = (hsi_img2,cv2.COLOR_HSV2BGR) ("Origin",rgb_img) ("HSI", hsi_img) ("RGB",rgb_img2) ("OpenCV_HSI",hsi_img2) ("OpenCV_RGB",rgb_img3) ("",hsi_img) ("", rgb_img2) ("OpenCV_HSI.jpeg", hsi_img2) ("OpenCV_RGB.jpeg", rgb_img3) () () if __name__ == '__main__': run_main()