The alpha() function is identical to the wand color() function. Similar to color() function, alpha() function draws a color on the image using current fill color, starting at specified position & method. Uses same arguments as color() method.
Syntax: wand.drawing.alpha(x, y, method) Parameters :
Parameter Input Type Description x numbers.Integer start of filling color y numbers.Integer end of filling color method basestring method from PAINT_METHOD_TYPES
The following are the PAINT_METHOD_TYPES:
- 'point' alters a single pixel.
- 'replace' swaps on color for another. Threshold is influenced by fuzz.
- 'floodfill' fills area of a color influenced by fuzz.
- 'filltoborder' fills area of a color until border defined by border_color.
- 'reset' replaces the whole image to a single color.
Note: This method replaces matte() in ImageMagick version 7. An AttributeError will be raised if attempting to call on a library without DrawAlpha support. Example #1:
# Import required objects from wand modules
from wand.image import Image
from wand.drawing import Drawing
from wand.color import Color
# generate object for wand.drawing
with Drawing() as draw:
draw.alpha(100, 100, 'point')
with Image(width = 200,
height = 200) as img:
# draw shape on image using draw() function
draw.draw(img)
img.save(filename ='color.png')
Output: A pixel is visible at center of transparent image here is the zoomed image. 
Example #2: Filling color using a flood-fill algorithm.
# Import required objects from wand modules
from wand.image import Image
from wand.drawing import Drawing
from wand.color import Color
# generate object for wand.drawing
with Drawing() as draw:
draw.fill_color = Color('blue')
draw.alpha(10, 35, 'floodfill')
with Image(width = 200,
height = 200,
background = Color('white')) as img:
# draw shape on image using draw() function
draw.draw(img)
img.save(filename ='color2.png')
Output: 