How to check dimensions of all images in a directory using python?

Solution 1:

If you don't need the rest of PIL and just want image dimensions of PNG, JPEG and GIF then this small function (BSD license) does the job nicely:

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

Solution 2:

One common way is to use PIL, the python imaging library to get the dimensions:

from PIL import Image
import os.path

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

Then you need to loop over the files in your directory, check the dimensions against your required dimensions, and move those files that do not match.

Solution 3:

You can use the Python Imaging Library (aka PIL) to read the image headers and query the dimensions.

One way to approach it would be to write yourself a function that takes a filename and returns the dimensions (using PIL). Then use the os.path.walk function to traverse all the files in the directory, applying this function. Collecting the results, you can build a dictionary of mappings filename -> dimensions, then use a list comprehension (see itertools) to filter out those that do not match the required size.

Solution 4:

Here is a script that does what you need:

#!/usr/bin/env python

"""
Get information about images in a folder.
"""

from os import listdir
from os.path import isfile, join

from PIL import Image


def print_data(data):
    """
    Parameters
    ----------
    data : dict
    """
    for k, v in data.items():
        print("%s:\t%s" % (k, v))
    print("Min width: %i" % data["min_width"])
    print("Max width: %i" % data["max_width"])
    print("Min height: %i" % data["min_height"])
    print("Max height: %i" % data["max_height"])


def main(path):
    """
    Parameters
    ----------
    path : str
        Path where to look for image files.
    """
    onlyfiles = [f for f in listdir(path) if isfile(join(path, f))]

    # Filter files by extension
    onlyfiles = [f for f in onlyfiles if f.endswith(".jpg")]

    data = {}
    data["images_count"] = len(onlyfiles)
    data["min_width"] = 10 ** 100  # No image will be bigger than that
    data["max_width"] = 0
    data["min_height"] = 10 ** 100  # No image will be bigger than that
    data["max_height"] = 0

    for filename in onlyfiles:
        im = Image.open(filename)
        width, height = im.size
        data["min_width"] = min(width, data["min_width"])
        data["max_width"] = max(width, data["max_width"])
        data["min_height"] = min(height, data["min_height"])
        data["max_height"] = max(height, data["max_height"])

    print_data(data)


if __name__ == "__main__":
    main(path=".")