Simple analyser for Imagefiles

image_analyse.py

from os import walk
from os.path import isfile, isdir
from sys import argv
from math import sqrt
import numpy as np
from progressbar import ProgressBar, Percentage, Bar
from PIL import Image

MAX_SIZE = 1000

def get_colors(imgs):
    colors = []
    for img in imgs:
        width, height = img.size
        for x in range(width):
            for y in range(height):
                colors.append(img.getpixel((x, y)))
    return colors

IMAGE_EXTS = ('.jpg', '.jpeg', '.png', '.gif')

def is_imgfilename(filename):
    for ext in IMAGE_EXTS:
        if filename.endswith(ext):
            return True
    return False

def glob_imgfiles(dirname):
    img_filenames = []
    for dpath, _, filenames in walk(dirname):
        for filename in filenames:
            if is_imgfilename(filename):
                img_filenames.append('{}/{}'.format(dpath, filename))
                if len(img_filenames) == MAX_SIZE:
                    return img_filenames
    return img_filenames

filename = argv[1]
if isfile(filename):
    filenames = [filename]
elif isdir(filename):
    filenames = glob_imgfiles(filename)
else:
    print('{} is not exist.'.format(filename))
    quit()

widgets = ['load images: ', Percentage(), Bar()]
maxval = len(filenames) if len(filenames) < MAX_SIZE else MAX_SIZE
bar = ProgressBar(maxval=maxval, widgets=widgets).start()

try:
    colors = []
    for filename in filenames:
        image = Image.open(filename)
        colors.append(np.array(get_colors([image])))
        bar.update(bar.currval + 1)
    bar.finish()
except MemoryError:
    print('Memory Error is raised. len of colors: {}'.format(len(colors)))

numth_colors = lambda j: [color[j] for color in colors]
mean = (np.average(numth_colors(0)), np.average(numth_colors(1)),
        np.average(numth_colors(2)))
norm_mean = sqrt(mean[0] * mean[0] + mean[1] * mean[1] + mean[2] * mean[2])
std = (np.std(numth_colors(0)), np.std(numth_colors(1)),
       np.std(numth_colors(2)))
print('pixel mean:', mean)
print('pixed norm mean: ', norm_mean)
print('pixel stddev:', std)