DIY 一个用于生成桌面墙纸的“网络相机”

#! /usr/bin/env python
 
# Copyright 2009 by Benjamin Fogle
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
import sys
import os
import os.path
import urllib2
import tempfile
import math
 
# Constants.  Change these to customize the script
# In ksh: CONFIG_FILE=$HOME/lectures/examples/LEC-05/webcam_config
CONFIG_FILE=os.getenv('HOME') + '/.webcam_config'
TARGET=os.getenv('HOME') + '/Pictures/Wallpapers/webcam.jpg'
SCREEN_X = 1024
SCREEN_Y = 768
 
def GetTiles(num_images):
    """Returns a tuple (N,M) representing the tile grid"""
    # This algorithm could be much improved
    tile = math.ceil(math.sqrt(N))
    return (tile, tile)
 
def GetImageSize(N, M):
    """Returns a the max size of each image based on the screen size
    and the tile grid"""
    global SCREEN_X
    global SCREEN_Y
    ImgX = SCREEN_X / N
    ImgY = SCREEN_Y / M
    return (ImgX, ImgY)
 
def CopyFile(src_fp, dest_fp):
    """Copy a file intelligently"""
    data = src_fp.read(49152)   # Copy 48k at a time
    while data:
        dest_fp.write(data)
        data = src_fp.read(49152)
    # Note: shutils.copyfileobj does this too.
 
if len(sys.argv) != 1:
    print "Usage: %s" % (sys.argv[0])
    print
    print "Config file is located in %s" % CONFIG_FILE
    sys.exit(1)
 
# Make sure the config file is readable and that it is a regular file
# There is a better way to do this that we will learn later.
if not os.access(CONFIG_FILE, os.R_OK) or not os.path.isfile(CONFIG_FILE):
    print "Error: %s could not be opened!" % CONFIG_FILE
    sys.exit(2)
 
urls = []           # Url to download from.  Read from config file
captions = []       # Captions for each image. Read from config file
filenames = []      # Temporary file names
 
config_fp = open(CONFIG_FILE, 'r')
line = config_fp.readline()
N=0
while line:
    params = line.split(":::")
    urls.append(params[0].strip())
    captions.append(params[1].strip())
    line = config_fp.readline()
    N+=1
config_fp.close()
 
 
# Download each url.  This is how to iterate over mutliple lists at once
for url, caption in zip(urls, captions):
    url_fp = urllib2.urlopen(url)
    # The following two lines are the preffered way to open a temporary
    # file.
    fd, name = tempfile.mkstemp()
    img_fp = os.fdopen(fd, 'w')
    filenames.append(name)
    CopyFile(url_fp, img_fp)
    url_fp.close()
    img_fp.close()  # The data won't appear in img_fp until it's closed
    # Use the ImageMagick suite from the shell to add a caption
    os.system("convert '%s' -set comment '%s' '%s'" % \
              (name, caption, name))
 
# Figure out the parameters
tilex, tiley = GetTiles(N)
imgx, imgy = GetImageSize(tilex, tiley)
 
# Use ImageMagick again to assemble the wallpaper
cmd = "montage -geometry %dx%d \
               -tile %dx%d \
               -set caption '%%c' \
               -pointsize 32 \
               -size %dx%d \
               -texture plasma: \
               +polaroid \
               -background black " % (imgx, imgy, tilex, tiley,
                       SCREEN_X, SCREEN_Y)
 
# Add each image file to the command string
for filename in filenames:
    cmd += '"%s" ' % filename
 
# Add the output file to the command string and execute
cmd += TARGET
os.system(cmd)
 
# Cleanup
for filename in filenames:
    os.unlink(filename)     # In ksh:  rm $filename

...... ......

# Use ImageMagick again to assemble the wallpaper
cmd = "montage -geometry %dx%d \
               -tile %dx%d \
               -set caption '%%c' \
               -pointsize 32 \
               ...... ......

...... ......

# Use ImageMagick again to assemble the wallpaper
cmd = "montage -geometry %dx%d \
               -font /usr/share/fonts/winfonts/msyh.ttf \
               -tile %dx%d \
               -set caption '%%c' \
               -pointsize 32 \
               ...... ......