Python Wand black_threshold()用法及代码示例

black_threshold()函数是Python Wand ImageMagick库中的内置函数，用于将高于给定颜色的所有像素强制为黑色，并保持阈值以上的所有像素不变。

 用法：

black_threshold(color)

参数：该函数接受上面提到并在下面定义的单个参数：

color:此参数用于指定因子值以应用黑色阈值。此参数接受诸如“绿色”，“蓝色”，“红色”，“白色”等颜色字符串的值。

返回值：此函数返回Wand ImageMagick对象。

原始图片：

范例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 black_threshold:
        # Invoke black_threshold function with threshold parameter as 'Green' 
        black_threshold.black_threshold('Green') 
        # Save the image 
        black_threshold.save(filename ='black_threshold1.jpg')

输出：

范例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 black_threshold function with with threshold parameter as 'White' 
        pic.black_threshold('White') 
        # Save the image  
        pic.save(filename ='black_threshold2.jpg')

输出：

相关用法

注：本文由纯净天空筛选整理自sarthak_ishu11大神的英文原创作品 Wand black_threshold() function – Python。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。