如何使用 ImageDraw 模糊椭圆

Question

我实现了一种检测人脸的算法，我想对人脸进行模糊处理。我正在使用 PIL 来模糊它。

image = Image.open(path_img)
draw = ImageDraw.Draw(image)
draw.ellipse((top, left, bottom, right), fill = 'white', outline ='white')

我的代码得到了这个

Face to blur

我想使用：

blurred_image = cropped_image.filter(ImageFilter.GaussianBlur(radius=10 ))

但我不能使用它，因为我使用的是 ImageDraw 并且它仅适用于 Image 类。如何用椭圆（圆形）模糊脸部？

谢谢

Answer 1

模糊椭圆是最好的方法

使用 Pillow，最好的方法是使用模糊椭圆作为 composite 的混合蒙版。

from PIL import Image, ImageDraw, ImageFilter


def make_ellipse_mask(size, x0, y0, x1, y1, blur_radius):
    img = Image.new("L", size, color=0)
    draw = ImageDraw.Draw(img)
    draw.ellipse((x0, y0, x1, y1), fill=255)
    return img.filter(ImageFilter.GaussianBlur(radius=blur_radius))


kitten_image = Image.open("kitten.jpg")
overlay_image = Image.new("RGB", kitten_image.size, color="orange")  # This could be a bitmap fill too, but let's just make it orange
mask_image = make_ellipse_mask(kitten_image.size, 150, 70, 350, 250, 5)
masked_image = Image.composite(overlay_image, kitten_image, mask_image)
masked_image.show()

给定this adorable kitten作为输入，输出是

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编辑：灵感来自 Mark Setchell 的回答，只需将 overlay_image 行更改为

overlay_image = kitten_image.filter(ImageFilter.GaussianBlur(radius=15))

为我们提供了这种模糊变体（模糊的边缘平滑:)）

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Answer 2

不确定您是想在图像上合成一些东西以隐藏内容还是模糊它。这更模糊:-)

从帕丁顿开始：

你可以像这样进入“隐身模式”：

#!/usr/bin/env python3

from PIL import Image, ImageDraw, ImageFilter
import numpy as np

# Open image
im = Image.open('paddington.png')

# Make a mask the same size as the image filled with black
mask = Image.new('RGB',im.size)

# Draw a filled white circle onto the black mask
draw = ImageDraw.Draw(mask)
draw.ellipse([90,40,300,250],fill=(255,255,255))

# Blur the entire image
blurred = im.filter(ImageFilter.GaussianBlur(radius=15))

# Select either the original or the blurred image at each pixel, depending on the mask
res = np.where(np.array(mask)>0,np.array(blurred),np.array(im)) 

# Convert back to PIL Image and save
Image.fromarray(res).save('result.png')

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或者，正如@AKX 所建议的，您可以删除 Numpy 依赖项并使代码也更小一些，但仍然得到相同的结果：

#!/usr/bin/env python3

from PIL import Image, ImageDraw, ImageFilter
import numpy as np

# Open image
im = Image.open('paddington.png')

# Make a mask the same size as the image filled with black
mask = Image.new('L',im.size)

# Draw a filled white circle onto the black mask
draw = ImageDraw.Draw(mask)
draw.ellipse([90,40,300,250],fill=255)

# Blur the entire image
blurred = im.filter(ImageFilter.GaussianBlur(radius=15))

# Composite blurred image over sharp one within mask
res = Image.composite(blurred, im, mask)

# Save
res.save('result.png')