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Python Wand adaptive_threshold()用法及代码示例


adaptive_threshold()函数是Python Wand ImageMagick库中的内置函数,用于为每个像素应用阈值。它存在于wand.image类中。

用法:
adaptive_threshold(width, height, offset)

参数:该函数接受上面提到的和下面定义的三个参数:

  • width:此参数用于指定width的值,该值是X轴上相邻像素的大小。
  • height:此参数用于指定高度值,该值是Y轴上相邻像素的大小。
  • offset:此参数用于指定偏移量的值,该值是介于0.0和quantum_range之间的归一化数字。
    如果值低于偏移量,它将强制像素变黑。

注意:quantum_range:这是ImageMagick库支持的颜色通道的最大值。

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 adaptive_threshold:
        # Invoke adaptive_threshold function with width as 2, height as  
        # 3 and offset as 2 
        adaptive_threshold.adaptive_threshold(2, 3, 2) 
        # Save the image 
        adaptive_threshold.save(filename ='adaptive_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 adaptive_threshold function with width as 0, Height as 1 and offset as 0.3 
        pic.adaptive_threshold(4, 5, 0.7) 
        # Save the image  
        pic.save(filename ='adaptive_threshold2.jpg')

输出:




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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 adaptive_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。