Convert a PDF or PS files to CBZ files via Ghostscript

gs2cbz.py

#!/usr/bin/env python
'''Convert PDF or PS files to CBZ files

CBZ files are ZIP-compressed sets of image files, this script in particular creates PNG images
it takes filename and target resolution (DPI) as arguments

'''

import os, sys
import getopt, shutil
from tempfile import mkdtemp
from glob import glob
import zipfile
from optparse import OptionParser

if sys.platform == 'win32':
    ghostscript = 'gswin32c'
else:
    ghostscript == 'gs'

def usage():
    help = '''Convert PDF or PS to CBZ
    
    Usage:
        gs2png -r DPI file1 file2 ...
    where
        DPI - target resolution in dots per inch
    
    '''
    return help

def png_to_cbz(imgdir, name):
    imgfiles = glob(os.path.join(imgdir,'*.png'))
    cbzfile = zipfile.ZipFile(name+'.cbz', 'w', zipfile.ZIP_DEFLATED)
    for file in imgfiles:
        cbzfile.write(file, os.path.basename(file))
    cbzfile.close()

def gs_to_cbz(dpi, filename):
    name = os.path.basename(filename)
    base, ext = os.path.splitext(name)
    try:
        # create temp dir
        imgdir = mkdtemp('_gs2cbz', 'name_')
        #convert file to images creating the dir 'filename'
        outfname = os.path.join(imgdir, base+'-%03d.png')
        gsparams = {
                            'ghostscript':ghostscript,
                            'dpi':dpi,
                            'outfile':outfname,
                            'infile':filename,
                            'other':'-dSAFER -dBATCH -dNOPAUSE -sDEVICE=png16m -dTextAlphaBits=4',
                            }    
        os.system('%(ghostscript)s %(other)s -r%(dpi)i -sOutputFile="%(outfile)s" "%(infile)s"' %gsparams)
        #pack images to the zip archive next to the original file
        png_to_cbz(imgdir, base)
    except:
        print 'There were some errors.'
    finally:
        #remove temp dir with all files
        shutil.rmtree(imgdir)
    
def main():
    parser = OptionParser('Convert files to CBZ book with GhostScript')
    
    #default dpi is approximately equal to dpi of Nokia 5800 screen
    parser.add_option('--dpi', type='int', dest='dpi', default=228)
    options, args = parser.parse_args()
    
    for filename in args:
        gs_to_cbz(options.dpi, filename)

if __name__ == "__main__":
    main()