使用python将图像转换为矩阵 [英] Image to matrix using python

问题描述

我需要访问文件夹中的所有图像并将其存储在矩阵中。我能够使用matlab完成它，这里是代码：

I am required to access all images in a folder and store it in a matrix. I was able to do it using matlab and here is the code:

input_dir = 'C:\Users\Karim\Downloads\att_faces\New Folder';
image_dims = [112, 92];

filenames = dir(fullfile(input_dir, '*.pgm'));
num_images = numel(filenames);

images = [];
for n = 1:num_images
    filename = fullfile(input_dir, filenames(n).name);
    img = imread(filename);
    img = imresize(img,image_dims);   
end

但我需要使用python执行此操作，这是我的python代码：

but I am required to do it using python and here is my python code:

import Image
import os
from PIL import Image
from numpy import *
import numpy as np


#import images
dirname = "C:\\Users\\Karim\\Downloads\\att_faces\\New folder"


#get number of images and dimentions
path, dirs, files = os.walk(dirname).next()
num_images = len(files)
image_file = "C:\\Users\\Karim\\Downloads\\att_faces\\New folder\\2.pgm"
im = Image.open(image_file)
width, height = im.size



images = []

for x in xrange(1, num_images):
    filename = os.listdir(dirname)[x]
    img = Image.open(filename)
    img = im.convert('L')
    images[:, x] = img[:]

但我得到了是错误：
IOError：[Errno 2]没有这样的文件或目录：'10 .pgm'
虽然文件存在但是。

but I am getting this error: IOError: [Errno 2] No such file or directory: '10.pgm' although the file is present.

推荐答案

我不太确定你的目标是什么，但尝试更像这样的事情：

I'm not quite sure what your end goal is, but try something more like this:

import numpy as np
import Image
import glob

filenames = glob.glob('/path/to/your/files/*.pgm')
images = [Image.open(fn).convert('L') for fn in filenames]
data = np.dstack([np.array(im) for im in images])

这将产生宽度x高度x num_images numpy数组，假设您的所有图像具有相同的尺寸。

This will yield a width x height x num_images numpy array, assuming that all of your images have the same dimensions.

但是，您的图像将是未分类的，因此您可能需要执行文件名。 sort（）。

However, your images will be unsorted, so you may want to do filenames.sort().

此外，您可能想要或不想要3D numpy数组，但这完全取决于你的内容实际上在做。如果你只想单独操作每个框架，那么不要费心将它们堆叠成一个巨大的阵列。

Also, you may or may not want things as a 3D numpy array, but that depends entirely on what you're actually doing. If you just want to operate on each "frame" individually, then don't bother stacking them into one gigantic array.

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