如何使用python检查目录中所有图像的尺寸？

Question

我需要检查目录中图像的尺寸.目前它有大约700张图像.我只需要检查尺寸,如果尺寸与给定尺寸不匹配,它将被移动到另一个文件夹.我该如何开始？

Answer 1

如果您不需要PIL的其余部分并且只需要PNG,JPEG和GIF的图像尺寸,那么这个小功能(BSD许可证)可以很好地完成工作:

http://code.google.com/p/bfg-pages/source/browse/trunk/pages/getimageinfo.py

import StringIO
import struct

def getImageInfo(data):
    data = str(data)
    size = len(data)
    height = -1
    width = -1
    content_type = ''

    # handle GIFs
    if (size >= 10) and data[:6] in ('GIF87a', 'GIF89a'):
        # Check to see if content_type is correct
        content_type = 'image/gif'
        w, h = struct.unpack("<HH", data[6:10])
        width = int(w)
        height = int(h)

    # See PNG 2. Edition spec (http://www.w3.org/TR/PNG/)
    # Bytes 0-7 are below, 4-byte chunk length, then 'IHDR'
    # and finally the 4-byte width, height
    elif ((size >= 24) and data.startswith('\211PNG\r\n\032\n')
          and (data[12:16] == 'IHDR')):
        content_type = 'image/png'
        w, h = struct.unpack(">LL", data[16:24])
        width = int(w)
        height = int(h)

    # Maybe this is for an older PNG version.
    elif (size >= 16) and data.startswith('\211PNG\r\n\032\n'):
        # Check to see if we have the right content type
        content_type = 'image/png'
        w, h = struct.unpack(">LL", data[8:16])
        width = int(w)
        height = int(h)

    # handle JPEGs
    elif (size >= 2) and data.startswith('\377\330'):
        content_type = 'image/jpeg'
        jpeg = StringIO.StringIO(data)
        jpeg.read(2)
        b = jpeg.read(1)
        try:
            while (b and ord(b) != 0xDA):
                while (ord(b) != 0xFF): b = jpeg.read(1)
                while (ord(b) == 0xFF): b = jpeg.read(1)
                if (ord(b) >= 0xC0 and ord(b) <= 0xC3):
                    jpeg.read(3)
                    h, w = struct.unpack(">HH", jpeg.read(4))
                    break
                else:
                    jpeg.read(int(struct.unpack(">H", jpeg.read(2))[0])-2)
                b = jpeg.read(1)
            width = int(w)
            height = int(h)
        except struct.error:
            pass
        except ValueError:
            pass

    return content_type, width, height

Answer 2

一种常见的方法是使用PIL,即python成像库来获取尺寸:

from PIL import Image
import os.path

filename = os.path.join('path', 'to', 'image', 'file')
img = Image.open(filename)
print img.size

然后,您需要遍历目录中的文件,根据所需尺寸检查尺寸,并移动那些不匹配的文件.

Answer 3

您可以使用Python Imaging Library(aka PIL)读取图像标题并查询尺寸.

接近它的一种方法是为自己编写一个带有文件名并返回维度的函数(使用PIL).然后使用该os.path.walk函数遍历目录中的所有文件,应用此功能.收集结果,您可以构建映射字典filename -> dimensions,然后使用列表推导(请参阅itertools)过滤掉那些与所需大小不匹配的列表.