brightness_contrast()函數是Python Wand ImageMagick庫中的內置函數，用於更改圖像的亮度和對比度。
用法：
brightness_contrast(brightness, contrast, channel)
參數：該函數接受上麵提到的和下麵定義的三個參數：
- Brightness:此參數用於指定介於-100到100之間的亮度值。默認值為0。
- Contrast:此參數用於指定對比度值，該值介於-100到100之間。默認值為0。
- channel:此參數用於將圖像通道的值指定為未定義的‘red’, ‘gray’，‘cyan’, ‘green’，‘magenta’, ‘blue’，‘yellow’, ‘alpha’，‘opacity’, ‘black’，‘index’, ‘composite_channels’，‘all_channels，‘sync_channels’, ‘default_channels’。
返回值：此函數返回Wand ImageMagick對象。
原始圖片：
範例1：
# Import library from Image
from wand.image import Image
# Import the image
with Image(filename ='../geeksforgeeks.png') as image:
# Clone the image in order to process
with image.clone() as brightness_contrast:
# Invoke brightness_contrast function with brightness as 50, Contrast as 17
# channel as Red
brightness_contrast.brightness_contrast(int(50), int(17), 'Red')
# Save the image
brightness_contrast.save(filename ='brightness_contrast1.jpg')輸出：
範例2：
# Import libraries from the wand
from wand.image import Image
from wand.drawing import Drawing
from wand.color import Color
with Drawing() as draw:
# Set Stroke color the circle to black
draw.stroke_color = Color('black')
# Set Width of the circlw to 2
draw.stroke_width = 1
# Set the fill color to 'White (# FFFFFF)'
draw.fill_color = Color('white')
# Invoke Circle function with center at 50, 50 and radius 25
draw.circle((200, 200), # Center point
(100, 100)) # Perimeter point
# Set the font style
draw.font = '../Helvetica.ttf'
# Set the font size
draw.font_size = 30
with Image(width = 400, height = 400, background = Color('# 45ff33')) as pic:
# Set the text and its location
draw.text(int(pic.width / 3), int(pic.height / 2), 'GeeksForGeeks !')
# Draw the picture
draw(pic)
# Invoke brightness_contrast function with Brightness as -44, Contrast as 33
# Channel as Red
pic.brightness_contrast(int(-44), int(33), 'Red')
# Save the image
pic.save(filename ='brightness_contrast2.jpg')輸出：
注：本文由純淨天空篩選整理自 Wand brightness_contrast() function – Python。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。