在python中将图像转换为2D数组

Question

我想将图像转换为具有5列的2D数组,其中每行都是表格[r, g, b, x, y].x,y是像素的位置,r,g,b是像素值.(我将使用此数组作为机器学习模型的输入).在python中是否有比这更有效的实现？

import Image
import numpy as np

im = Image.open("farm.jpg")
col,row =  im.size
data = np.zeros((row*col, 5))
pixels = im.load()
for i in range(row):
    for j in range(col):
        r,g,b =  pixels[i,j]
        data[i*col + j,:] = r,g,b,i,j

Answer 1

最近我不得不写这篇文章并最终结束

indices = np.dstack(np.indices(im.shape[:2]))
data = np.concatenate((im, indices), axis=-1)

imnumpy数组在哪里？您可能最好直接将图像读入numpy数组

from scipy.misc import imread
im = imread("farm.jpg")

或者,如果您安装了Scikit Image,则更好

from skimage.io import imread
im = imread("farm.jpg")

Answer 2

我不确定这是否非常有效.但是,你走了,说arr = np.array(im); 然后你可以做这样的事情.

>>> arr = np.arange(150).reshape(5, 10, 3)
>>> x, y, z = arr.shape
>>> indices = np.vstack(np.unravel_index(np.arange(x*y), (y, x))).T
#or indices = np.hstack((np.repeat(np.arange(y), x)[:,np.newaxis], np.tile(np.arange(x), y)[:,np.newaxis]))
>>> np.hstack((arr.reshape(x*y, z), indices))
array([[  0,   1,   2,   0,   0],
       [  3,   4,   5,   0,   1],
       [  6,   7,   8,   0,   2],
       [  9,  10,  11,   0,   3],
       [ 12,  13,  14,   0,   4],
       [ 15,  16,  17,   1,   0],
       [ 18,  19,  20,   1,   1],
       [ 21,  22,  23,   1,   2],
       [ 24,  25,  26,   1,   3],
       [ 27,  28,  29,   1,   4],
       [ 30,  31,  32,   2,   0],
       [ 33,  34,  35,   2,   1],
       [ 36,  37,  38,   2,   2],
       ...
       [129, 130, 131,   8,   3],
       [132, 133, 134,   8,   4],
       [135, 136, 137,   9,   0],
       [138, 139, 140,   9,   1],
       [141, 142, 143,   9,   2],
       [144, 145, 146,   9,   3],
       [147, 148, 149,   9,   4]])