Python PIL | getbands() 和 getextrema() 方法

Python PIL 库包含 Image 模块，其中定义了各种功能。 PIL.Image.Image.getbands()
此方法用于获取图像中存在的模式（波段）。

Syntax: PIL.Image.Image.getbands(image_object [valid image path])
Parameters: 
It takes a parameter image_object i.e it the reference of the image which is opened using open() method or image path can also be mentioned.
Return value: Returns a tuple containing the name of each band in this image. For example, getbands on an RGB image returns (“R”, “G”, “B”).

Python3

# Importing Image module from PIL package
from PIL import Image
 
# Opening a multiband image
im = Image.open(r"C:\Users\Admin\Pictures\images.png")
 
# This returns the bands used in im (image)
im1 = Image.Image.getbands(im)
 
print("Multiband image", im1)
 
# Opening a single band image
im2 = Image.open(r"C:\Users\Admin\Pictures\singleband.png")
 
# This returns the band used in im2
im3 = Image.Image.getbands(im2)
 
print("Single band image", im3)

输出：

Multiband image ('R', 'G', 'B')
Single band image ('P', )

PIL.Image.Image.getextrema() 方法 –

获取图像中每个波段的最小和最大像素值。

Syntax: PIL.Image.Image.getextrema(image_object [valid image path])
Parameters: 
It takes a parameter image_object i.e it the reference of the image which is opened using open() method or image path can also be mentioned.
Return Value: For a single-band image, a 2-tuple containing the minimum and maximum pixel value. For a multi-band image, a tuple containing one 2-tuple for each band.

Python3

# importing Image module from PIL package
from  PIL import Image
 
# opening a multiband image
im = Image.open(r"C:\Users\Admin\Pictures\download.png")
 
# getting maximum and minimum pixels of
# multiband images (RBG)
im1 = Image.Image.getextrema(im)
 
print("Multi band image ", im1)
 
# Opening a single band image
im2 = Image.open(r"C:\Users\Admin\Pictures\singleband.png")
 
# getting maximum and minimum pixels of
# single band image
im3 = Image.Image.getextrema(im2)
 
print("Single band image ", im3)

输出：

Multi band image  ((73, 255), (0, 255), (0, 255))
Single band image  (0, 123)

上述文章中使用的这些图像 -
多波段图像

单波段图像