用Python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'))