错误模块‘object’没有属性'LANCZOS

Question

我想将图像大小调整为28*28像素的.jpeg。我使用名为PIL的模块来调整图片的大小:我创建了这个类：

from PIL import Image

#import PIL
import numpy
from resizeimage import resizeimage

import scipy.misc

''' This class is to resize input image to MNIST size (28x28 px) '''


class Resize_img:
    def __init__(self, imageName):
        print 'Image -- ', imageName
        self.resized_image = ''
        # resize img to mnist size [28x28]
        #with open(imageName,'r+b') as f:
        #    with Image.open(f) as image:
    image = Image.open(imageName)        
        cover = resizeimage.resize_cover(image, [28, 28])
        self.resized_image = 'new ' + imageName
        cover.save(self.resized_image, image.format)
        # transform img to MNIST form
        # image to ndarray 
        PILimg = PIL.Image.open(self.resized_image)

        self.mnist_image_input = scipy.misc.fromimage(PILimg,
                                                      True)  # True => space gray! ----------------------------------------------------
        self.mnist_image_input = (numpy.multiply(self.mnist_image_input,
                                                 1.0 / 255.0) - 1.0) * -1.0  # inverse the image :D  ( white -> dark )


def main():  # To test this Class.
    imageTest = '2.jpeg'  # The name of the image to resize

    imageTest = Resize_img(imageTest)
    scipy.misc.imshow(imageTest.mnist_image_input)


if __name__ == "__main__":
    main()


# sudo apt-get install libtiff4-dev libjpeg8-dev zlib1g-dev libfreetype6-dev liblcms2-dev libwebp-dev tcl8.5-dev tk8.5-dev python-tk

错误是：

Image --  2.jpeg
Traceback (most recent call last):
  File "Resize_img.py", line 40, in <module>
    main()
  File "Resize_img.py", line 35, in main
    imageTest = Resize_img(imageTest)
  File "Resize_img.py", line 18, in __init__
    with Image.open(f) as image:
  File "/usr/lib/python2.7/dist-packages/PIL/Image.py", line 528, in __getattr__
    raise AttributeError(name)
AttributeError: __exit__

如何解决此问题？

关于在模块PIL.Image中调整方法大小的帮助：

resize(self, size, resample=0) unbound PIL.Image.Image method
    Returns a resized copy of this image.

    :param size: The requested size in pixels, as a 2-tuple:
       (width, height).
    :param filter: An optional resampling filter.  This can be
       one of :py:attr:`PIL.Image.NEAREST` (use nearest neighbour),
       :py:attr:`PIL.Image.BILINEAR` (linear interpolation in a 2x2
       environment), :py:attr:`PIL.Image.BICUBIC` (cubic spline
       interpolation in a 4x4 environment), or
       :py:attr:`PIL.Image.ANTIALIAS` (a high-quality downsampling filter).
       If omitted, or if the image has mode "1" or "P", it is
       set :py:attr:`PIL.Image.NEAREST`.
    :returns: An :py:class:`~PIL.Image.Image` object.

Answer 1

正如其他人所提到的，这很可能是由于系统上没有安装LANCZOS而导致的一些缺失的依赖项。您可以尝试使用BILINEAR、BICUBIC、NEAREST或ANTIALIAS。要解决这个问题，我们需要深入研究大小图像包。假设包位于：/usr/local/lib/python3.4/dist-packages/resizeimage/

我们可以使用以下命令编辑大小图像文件：

sudo nano /usr/local/lib/python3.4/dist-packages/resizeimage/resizeimage.py

进入文件后，我们需要用ANTIALIAS替换LANCZOS。例如，在resize_cover函数中：

img = img.resize((new_size[0], new_size[1]), Image.LANCZOS)

变成：

img = img.resize((new_size[0], new_size[1]), Image.ANTIALIAS)

对于文件中的其余函数，依此类推。这应该可以解决您的问题。

Answer 2

这可能取决于您的PIL版本。在python shell中尝试这样做。

>>> import PIL.Image                                                                                                                      
>>> help(PIL.Image.Image.resize)

Answer 3

我实际上没有在你的代码中看到LANCZOS的用法，但是修复方法是用Image.ANTIALIAS替换Image.LANCZOS。您安装的Python版本可能与使用LANCZOS的版本不同。当涉及到缩小图像和使它们看起来清晰时，ANTIALIAS应该表现得同样好。