Python OpenCV cv2.imread()用法及代碼示例

OpenCV-Python是旨在解決計算機視覺問題的Python綁定庫。
cv2.imread()方法從指定的文件加載圖像。如果無法讀取圖像(由於缺少文件，權限不正確，格式不受支持或格式無效)，則此方法將返回一個空矩陣。

用法： cv2.imread(path, flag)

注意：該映像應位於工作目錄中，或者應提供完整的映像路徑。

所有三種類型的標誌描述如下：

cv2.IMREAD_COLOR: It specifies to load a color image. Any transparency of image will be neglected. It is the default flag. Alternatively, we can pass integer value 1 for this flag.
cv2.IMREAD_GRAYSCALE: It specifies to load an image in grayscale mode. Alternatively, we can pass integer value 0 for this flag.
cv2.IMREAD_UNCHANGED: It specifies to load an image as such including alpha channel. Alternatively, we can pass integer value -1 for this flag.

用於以下所有示例的圖像：

示例1:使用默認標誌

# Python program to explain cv2.imread() method 
  
# importing cv2  
import cv2 
  
# path 
path = r'C:\Users\Rajnish\Desktop\geeksforgeeks.png'
  
# Using cv2.imread() method 
img = cv2.imread(path) 
  
# Displaying the image 
cv2.imshow('image', img)

輸出：

示例2:
以灰度模式加載圖像

# Python program to explain cv2.imread() method 
  
# importing cv2  
import cv2 
  
# path 
path = r'C:\Users\Rajnish\Desktop\geeksforgeeks.png'
  
# Using cv2.imread() method 
# Using 0 to read image in grayscale mode 
img = cv2.imread(path, 0) 
  
# Displaying the image 
cv2.imshow('image', img)

輸出：