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# -*- coding: utf-8 -*-
#
# (c) Copyright 2001-2006 Hewlett-Packard Development Company, L.P.
#
# 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 2 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Author: Don Welch
#
# Ported from Perl's Image::Size module by Randy J. Ray
#
import os, os.path, re, struct
xbm_pat = re.compile(r'^\#define\s*\S*\s*(\d+)\s*\n\#define\s*\S*\s*(\d+)', re.IGNORECASE)
xpm_pat = re.compile(r'"\s*(\d+)\s+(\d+)(\s+\d+\s+\d+){1,2}\s*"', re.IGNORECASE)
ppm_pat1 = re.compile(r'^\#.*', re.IGNORECASE | re.MULTILINE)
ppm_pat2 = re.compile(r'^(P[1-6])\s+(\d+)\s+(\d+)', re.IGNORECASE)
ppm_pat3 = re.compile(r'IMGINFO:(\d+)x(\d+)', re.IGNORECASE)
tiff_endian_pat = re.compile(r'II\x2a\x00')
def readin(stream, length, offset=0):
if offset != 0:
stream.seek(offset, 0)
return stream.read(length)
def xbmsize(stream):
width, height = -1, -1
match = xbm_pat.match(readin(stream,1024))
try:
width = int(match.group(1))
height = int(match.group(2))
except:
pass
return width, height
def xpmsize(stream):
width, height = -1, -1
match = re.search(xpm_pat, readin(stream, 1024))
try:
width = int(match.group(1))
height = int(match.group(2))
except:
pass
return width, height
def pngsize(stream): # also does MNG
width, height = -1, -1
if readin(stream, 4, 12) in ('IHDR', 'MHDR'):
height, width = struct.unpack("!II", stream.read(8))
return width,height
def jpegsize(stream):
width, height = -1, -1
stream.seek(2)
while True:
length = 4
buffer = readin(stream, length)
try:
marker, code, length = struct.unpack("!c c h", buffer)
except:
break
if marker != '\xff':
break
if 0xc0 <= ord(code) <= 0xc3:
length = 5
height, width = struct.unpack("!xhh", readin(stream, length))
else:
readin(stream, length-2)
return width, height
def ppmsize(stream):
width, height = -1, -1
header = re.sub(ppm_pat1, '', readin(stream, 1024))
match = ppm_pat2.match(header)
typ = ''
try:
typ = match.group(1)
width = int(match.group(2))
height = int(match.group(3))
except:
pass
if typ == 'P7':
match = ppm_pat3.match(header)
try:
width = int(match.group(1))
height = int(match.group(2))
except:
pass
return width, height
def tiffsize(stream):
header = readin(stream, 4)
endian = ">"
match = tiff_endian_pat.match(header)
if match is not None:
endian = "<"
input = readin(stream, 4, 4)
offset = struct.unpack('%si' % endian, input)[0]
num_dirent = struct.unpack('%sH' % endian, readin(stream, 2, offset))[0]
offset += 2
num_dirent = offset+(num_dirent*12)
width, height = -1, -1
while True:
ifd = readin(stream, 12, offset)
if ifd == '' or offset > num_dirent:
break
offset += 12
tag = struct.unpack('%sH'% endian, ifd[0:2])[0]
type = struct.unpack('%sH' % endian, ifd[2:4])[0]
if tag == 0x0100:
width = struct.unpack("%si" % endian, ifd[8:12])[0]
elif tag == 0x0101:
height = struct.unpack("%si" % endian, ifd[8:12])[0]
return width, height
def bmpsize(stream):
width, height = struct.unpack("<II", readin(stream, 8, 18))
return width, height
def gifsize(stream):
# since we only care about the printed size of the image
# we only need to get the logical screen sizes, which are
# the maximum extents of the image. This code is much simpler
# than the code from Image::Size
#width, height = -1, -1
buf = readin(stream, 7, 6) # LSx, GCTF, etc
height, width, flags, bci, par = struct.unpack('<HHBBB', buf)
return width, height
TYPE_MAP = {re.compile('^GIF8[7,9]a') : ('image/gif', gifsize),
re.compile("^\xFF\xD8") : ('image/jpeg', jpegsize),
re.compile("^\x89PNG\x0d\x0a\x1a\x0a") : ('image/png', pngsize),
re.compile("^P[1-7]") : ('image/x-portable-pixmap', ppmsize),
re.compile('\#define\s+\S+\s+\d+') : ('image/x-xbitmap', xbmsize),
re.compile('\/\* XPM \*\/') : ('image/x-xpixmap', xpmsize),
re.compile('^MM\x00\x2a') : ('image/tiff', tiffsize),
re.compile('^II\*\x00') : ('image/tiff', tiffsize),
re.compile('^BM') : ('image/x-bitmap', bmpsize),
re.compile("^\x8aMNG\x0d\x0a\x1a\x0a") : ('image/png', pngsize),
}
def imagesize(filename, mime_type=''):
width, height = -1, -1
f = file(filename, 'r')
buffer = f.read(4096)
if not mime_type:
for t in TYPE_MAP:
match = t.search(buffer)
if match is not None:
mime_type, func = TYPE_MAP[t]
break
if mime_type and func:
f.seek(0)
width, height = func(f)
else:
width, height = -1, -1
f.close()
return height, width, mime_type
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