====== Compare folder contents ======
===== Find incoherence in your backups =====
<code bash>
~/multimedia$ find ./photographs/ -type f -exec sha1sum {} \; | sort > dir1_sha1
~/multimedia$ cd /mnt/nas/
/mnt/nas$ find ./photographs/ -type f -exec sha1sum {} \; | sort > dir2_sha1
/mnt/nas$ diff --brief /home/cedric/multimedia/dir1_sha1 ./dir2_sha1
</code>



====== Focal length repartition ======

<code python>
#!/usr/bin/env python
# -*- coding: utf-8 -*-

import pylab
import glob
from collections import Counter

from PIL import Image
from PIL.ExifTags import TAGS


DIRECTORY = "/home/cedric/vienna/*.JPG"


def get_exif(fn):
    ret = {}
    i = Image.open(fn)
    info = i._getexif()
    if info is not None:
        for tag, value in info.items():
            decoded = TAGS.get(tag, tag)
            ret[decoded] = value
    return ret



if __name__ == "__main__":
    cnt = Counter()
    pictures = glob.glob(DIRECTORY)
    focal = Counter()
    for picture in pictures:
        exif = get_exif(picture)
        if exif != {}:
            focal[exif['FocalLength'][0]] += 1

    if focal:
        length = len(focal)
        ind = pylab.arange(length)
        width = 0.35 # bars width

        focal_list = [elem for elem in focal.keys()]
        focal_count = [elem for elem in focal.values()]
        max_focal_count = max(focal_count)  # max focal_count

        p = pylab.bar(ind, focal_count, width, color='r')

        pylab.ylabel("Number of shots")
        pylab.xlabel("Focal length")
        pylab.title("Focal length repartition for " + str(sum(focal_count)) + " pictures")
        pylab.xticks(ind + (width / 2), focal_list)
        pylab.xlim(-width, len(ind))

        # changing the ordinate scale according to the max.
        if max_focal_count <= 100:
            pylab.ylim(0, max_focal_count + 5)
            pylab.yticks(pylab.arange(0, max_focal_count + 5, 5))
        elif max_focal_count <= 200:
            pylab.ylim(0, max_focal_count + 10)
            pylab.yticks(pylab.arange(0, max_focal_count + 10, 10))
        elif max_focal_count <= 600:
            pylab.ylim(0, max_focal_count + 25)
            pylab.yticks(pylab.arange(0, max_focal_count + 25, 25))
        elif max_focal_count <= 800:
            pylab.ylim(0, max_focal_count + 50)
            pylab.yticks(pylab.arange(0, max_focal_count + 50, 50))


        for rect in p:
            height = rect.get_height()
            pylab.text(rect.get_x()+rect.get_width()/2., 1.05*height, '%d'%int(height),
                    ha='center', va='bottom')


        pylab.show()
    else:
        print "No result."
</code>
        
        
        
====== Piwigo ======

<code python>
! /usr/local/bin/python
-*- coding: utf-8 -*- 

"""piwigo.py

Usefull for your Piwigo gallery (http://www.piwigo.org/).

./piwigo

    ./photos
        ./thumbnail/
        ./pwg_high/
            ./original_image01.jpg
            .
            .
            ./original_imageN.jpg
    ./piwigo.py

Resize images from /pwg_high (original images) directory in two size :

 - 128*128 pixels in ./piwigo/photos/thumbnail ;
 - 1024*768 pixels in ./piwigo/photos/ .

"""

__author__ = "Cedric Bonhomme"
__date__ = "$Date: 2009/03/22 $"
__copyright__ = "Copyright (c) 2009 Cedric Bonhomme"
__license__ = "GPL v3"

import re import os import Image

def search_files(motif, root_path):

    """Return a list of tuple (path, files).

    Search fo files containing 'motif' that
    aren't symbolic links.
    """
    result = []
    w = os.walk(root_path)
    for (path, dirs, files) in w:
        for f in files:
            if re.compile(motif).search(f):
                # if not a symbolic link
                if not os.path.islink(os.path.join(path, f)):
                    result.append((os.path.join(path, f), f))
    return result

images = search_files(".jpg", "./photos/pwg_high")

for image in images:

    im = Image.open(image[0])

    im_thumbnail = im.resize((128, 128), Image.ANTIALIAS)
    im_thumbnail.save("./photos/thumbnail/TN-" + image[1], quality = 100)

    im_slide = im.resize((1024, 768), Image.NEAREST)
    im_slide.save("./photos/" + image[1], quality = 100)

""" Filter options to resize the image :

    Use nearest neighbour :
        Image.NEAREST
    Linear interpolation in a 2x2 environment :
        Image.BILINEAR
    Cubic spline interpolation in a 4x4 environment :
        Image.BICUBIC
    Best down-sizing filter :
        Image.ANTIALIAS

"""
</code>

On peut facilement ajouter le transfert FTP du résultat dans le dossier distant qui va bien.


====== Watermark avec ImageMagick ======

<code bash>
$ convert 16-04-2008_0167.jpg -font Arial -pointsize 40 -draw "gravity south > fill black text 0,12 'Cédric Bonhomme' > fill white text 1,11 'Cédric Bonhomme' " wmark_text_drawn.jpg
</code>


====== Effet Polaroid ======

<code bash>
$ convert picture.jpg -thumbnail 240 -bordercolor white -background black +polaroid picture-pola.png
</code>