用Python PIL实现几个简单的图片特效

import numpy as np
from PIL import Image

im = Image.open(imagename).convert('RGB')
arr = np.array(im)

In [566]: arr.shape
Out[566]: (313, 450, 3)

IN [567]: arr[0][0]
Out[567]: array([6, 4, 9], dtype=uint8)

def blackWithe(imagename):
  # r,g,b = r*0.299+g*0.587+b*0.114
  im = np.asarray(Image.open(imagename).convert('RGB'))
  trans = np.array([[0.299,0.587,0.114],[0.299,0.587,0.114],[0.299,0.587,0.114]]).transpose()
  im = np.dot(im,trans)
  return Image.fromarray(np.array(im).astype('uint8'))

def fleeting(imagename,params=12):
  im = np.asarray(Image.open(imagename).convert('RGB'))
  im1 = np.sqrt(im*[1.0,0.0,0.0])*params
  im2 = im*[0.0,1.0,1.0]
  im = im1+im2
  return Image.fromarray(np.array(im).astype('uint8')) 

def oldFilm(imagename):
  im = np.asarray(Image.open(imagename).convert('RGB'))
  # r=r*0.393+g*0.769+b*0.189 g=r*0.349+g*0.686+b*0.168 b=r*0.272+g*0.534b*0.131
  trans = np.array([[0.393,0.769,0.189],[0.349,0.686,0.168],[0.272,0.534,0.131]]).transpose()
  # clip 超过255的颜色置为255
  im = np.dot(im,trans).clip(max=255)        
  return Image.fromarray(np.array(im).astype('uint8')) 

def reverse(imagename):
  im = 255 - np.asarray(Image.open(imagename).convert('RGB'))
  return Image.fromarray(np.array(im).astype('uint8')) 

from PIL import Image, ImageFilter

# 打开一个jpg图像文件，注意是当前路径:
im = Image.open('Penguins.jpg')



# 模糊
im2 = im.filter(ImageFilter.BLUR)
# 模糊可设置模糊的程度
im22 = im.filter(ImageFilter.BoxBlur(200))
# 轮廓滤波
im3 = im.filter(ImageFilter.CONTOUR)
# 边缘增强滤波（锐化）
im4 = im.filter(ImageFilter.EDGE_ENHANCE)
# 浮雕滤波
im5 = im.filter(ImageFilter.EMBOSS)
# 寻找边缘信息的滤波
im6 = im.filter(ImageFilter.FIND_EDGES)

im2.save('BLUR.jpg', 'jpeg')
im3.save('CONTOUR.jpg', 'jpeg')
im4.save('EDGE_ENHANCE.jpg', 'jpeg')
im5.save('EMBOSS.jpg', 'jpeg')
im6.save('FIND_EDGES.jpg', 'jpeg')
im22.save('BoxBlur(200).jpg', 'jpeg')