python rgb 图像

A colored image can be represented as a 3 order matrix. The first order is for the rows, the second order is for the columns and the third order is for specifying the color of the corresponding pixel. Here, we use the BGR color format(because OpenCV python library works on BGR format, not on RGB), so the third order will take 3 values of Blue, Green, and Red respectively.

彩色图像可以表示为3阶矩阵。 第一个顺序用于行，第二个顺序用于列，第三个顺序用于指定相应像素的颜色。 在这里，我们使用BGR颜色格式(因为OpenCV python库适用于BGR格式，而不适用于RGB)，因此三阶分别采用蓝色，绿色和红色这3个值。

Colour planes of BGR image:

BGR图像的彩色平面：

Consider a BGR image array I then,

考虑一个BGR图像阵列我然后，

• I[:, :, 0] represents the Blue colour plane of the BGR image

  I [:,：，0]表示BGR图像的蓝色平面

• I[:, :, 1] represents the Green colour plane of the BGR image

  I [:,：，1]表示BGR图像的绿色平面

• I[:, :, 2] represents the Red colour plane of the BGR image

  I [:,：，2]表示BGR图像的红色平面

In this program, we will be using two functions of OpenCV-python (cv2) module. let's see their syntax and descriptions first :

在此程序中，我们将使用OpenCV-python(cv2)模块的两个功能。 我们先来看一下它们的语法和描述：

1) imread():
It takes an absolute path/relative path of your image file as an argument and returns its corresponding image matrix.

1)imread()：
它以图像文件的绝对路径/相对路径作为参数，并返回其对应的图像矩阵。

2) imshow():
It takes window name and image matrix as an argument in order to display an image in a display window with a specified window name.

2)imshow()：
它以窗口名称和图像矩阵为参数，以便在具有指定窗口名称的显示窗口中显示图像。

3) shape: This is the attribute of an image matrix which return shape of an image i.e. consisting of number of rows ,columns and number of planes.

3)形状：这是图像矩阵的属性，其返回图像的形状，即由行数，列数和平面数组成。

Python程序可显示RGB图像的不同平面 (Python program to display different planes of an RGB image)

# open-cv library is installed as cv2 in python
# import cv2 library into this program
import cv2
# import numpy library as np
import numpy as np
# read an image using imread() function of cv2
# we have to  pass only the path of the image
img = cv2.imread(r'C:/Users/user/Desktop/pic4.jpg')
# displaying the image using imshow() function of cv2
# In this : 1st argument is name of the frame
# 2nd argument is the image matrix
cv2.imshow('original image',img)
# shape attribute of an image matrix gives the dimensions
row,col,plane = img.shape
# here image is of class 'uint8', the range of values
# that each colour component can have is [0 - 255]
# create a zero matrix of order same as
# original image matrix order of same dimension
temp = np.zeros((row,col,plane),np.uint8)
# store blue plane contents or data of image matrix
# to the corresponding plane(blue) of temp matrix
temp[:,:,0] = img[:,:,0]
# displaying the Blue plane image
cv2.imshow('Blue plane image',temp)
# again take a zero matrix of image matrix shape
temp = np.zeros((row,col,plane),np.uint8)
# store green plane contents or data of image matrix
# to the corresponding plane(green) of temp matrix
temp[:,:,1] = img[:,:,1]
# displaying the Green plane image
cv2.imshow('Green plane image',temp)
# again take a zero matrix of image matrix shape
temp = np.zeros((row,col,plane),np.uint8)
# store red plane contents or data of image matrix
# to the corresponding plane(red) of temp matrix
temp[:,:,2] = img[:,:,2]
# displaying the Red plane image
cv2.imshow('Red plane image',temp)

Output

输出量

翻译自: https://www.includehelp.com/python/show-different-planes-of-an-rgb-image.aspx

python rgb 图像