#!/usr/bin/env python
import cStringIO
import struct
import os, os.path
from pdftypes import LITERALS_DCT_DECODE
from pdfcolor import LITERAL_DEVICE_GRAY, LITERAL_DEVICE_RGB, LITERAL_DEVICE_CMYK
def align32(x):
return ((x+3)//4)*4
## BMPWriter
##
class BMPWriter(object):
def __init__(self, fp, bits, width, height):
self.fp = fp
self.bits = bits
self.width = width
self.height = height
if bits == 1:
ncols = 2
elif bits == 8:
ncols = 256
elif bits == 24:
ncols = 0
else:
raise ValueError(bits)
self.linesize = align32((self.width*self.bits+7)//8)
self.datasize = self.linesize * self.height
headersize = 14+40+ncols*4
info = struct.pack('<IiiHHIIIIII', 40, self.width, self.height, 1, self.bits, 0, self.datasize, 0, 0, ncols, 0)
assert len(info) == 40, len(info)
header = struct.pack('<ccIHHI', 'B', 'M', headersize+self.datasize, 0, 0, headersize)
assert len(header) == 14, len(header)
self.fp.write(header)
self.fp.write(info)
if ncols == 2:
# B&W color table
for i in (0, 255):
self.fp.write(struct.pack('BBBx', i, i, i))
elif ncols == 256:
# grayscale color table
for i in xrange(256):
self.fp.write(struct.pack('BBBx', i, i, i))
self.pos0 = self.fp.tell()
self.pos1 = self.pos0 + self.datasize
return
def write_line(self, y, data):
self.fp.seek(self.pos1 - (y+1)*self.linesize)
self.fp.write(data)
return
## ImageWriter
##
class ImageWriter(object):
def __init__(self, outdir):
self.outdir = outdir
if not os.path.exists(self.outdir):
os.makedirs(self.outdir)
return
def export_image(self, image):
stream = image.stream
filters = stream.get_filters()
(width, height) = image.srcsize
if len(filters) == 1 and filters[0] in LITERALS_DCT_DECODE:
ext = '.jpg'
elif (image.bits == 1 or
image.bits == 8 and image.colorspace in (LITERAL_DEVICE_RGB, LITERAL_DEVICE_GRAY)):
ext = '.%dx%d.bmp' % (width, height)
else:
ext = '.%d.%dx%d.img' % (image.bits, width, height)
name = image.name+ext
path = os.path.join(self.outdir, name)
fp = file(path, 'wb')
if ext == '.jpg':
raw_data = stream.get_rawdata()
if LITERAL_DEVICE_CMYK in image.colorspace:
from PIL import Image
from PIL import ImageChops
ifp = cStringIO.StringIO(raw_data)
i = Image.open(ifp)
i = ImageChops.invert(i)
i = i.convert('RGB')
i.save(fp, 'JPEG')
else:
fp.write(raw_data)
elif image.bits == 1:
bmp = BMPWriter(fp, 1, width, height)
data = stream.get_data()
i = 0
width = (width+7)//8
for y in xrange(height):
bmp.write_line(y, data[i:i+width])
i += width
elif image.bits == 8 and image.colorspace is LITERAL_DEVICE_RGB:
bmp = BMPWriter(fp, 24, width, height)
data = stream.get_data()
i = 0
width = width*3
for y in xrange(height):
bmp.write_line(y, data[i:i+width])
i += width
elif image.bits == 8 and image.colorspace is LITERAL_DEVICE_GRAY:
bmp = BMPWriter(fp, 8, width, height)
data = stream.get_data()
i = 0
for y in xrange(height):
bmp.write_line(y, data[i:i+width])
i += width
else:
fp.write(stream.get_data())
fp.close()
return name
