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https://github.com/python-pillow/Pillow.git
synced 2025-01-11 17:56:18 +03:00
py3k: Rewrite PdfImagePlugin into something more legible
After adding all the encode() calls, the PDF plugin (and a few others) became much harder to read. This should be much easier on the eyes.
This commit is contained in:
Brian Crowell
Brian Crowell
parent
6765b8e026
commit
49b0d1563e
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@ -38,19 +38,16 @@ import io
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# 5. page contents
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def _obj(fp, obj, **dict):
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fp.write(("%d 0 obj\n" % obj).encode('ascii'))
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fp.write("%d 0 obj\n" % obj)
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if dict:
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fp.write(b"<<\n")
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fp.write("<<\n")
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for k, v in dict.items():
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if v is not None:
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if not isinstance(v, bytes):
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v = str(v).encode('ascii')
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fp.write(b"/" + k.encode('ascii') + b" " + v + b"\n")
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fp.write(b">>\n")
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fp.write("/%s %s\n" % (k, v))
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fp.write(">>\n")
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def _endobj(fp):
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fp.write(b"endobj\n")
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fp.write("endobj\n")
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##
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# (Internal) Image save plugin for the PDF format.
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@ -64,8 +61,18 @@ def _save(im, fp, filename):
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xref = [0]*(5+1) # placeholders
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fp.write(b"%PDF-1.2\n")
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fp.write(b"% created by PIL PDF driver " + __version__.encode('ascii') + b"\n")
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class TextWriter:
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def __init__(self, fp):
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self.fp = fp
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def __getattr__(self, name):
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return getattr(self.fp, name)
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def write(self, value):
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self.fp.write(value.encode('latin-1'))
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fp = TextWriter(fp)
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fp.write("%PDF-1.2\n")
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fp.write("% created by PIL PDF driver " + __version__ + "\n")
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#
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# Get image characteristics
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@ -80,33 +87,33 @@ def _save(im, fp, filename):
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params = None
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if im.mode == "1":
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filter = b"/ASCIIHexDecode"
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colorspace = b"/DeviceGray"
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filter = "/ASCIIHexDecode"
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colorspace = "/DeviceGray"
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procset = "/ImageB" # grayscale
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bits = 1
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elif im.mode == "L":
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filter = b"/DCTDecode"
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filter = "/DCTDecode"
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# params = "<< /Predictor 15 /Columns %d >>" % (width-2)
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colorspace = b"/DeviceGray"
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colorspace = "/DeviceGray"
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procset = "/ImageB" # grayscale
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elif im.mode == "P":
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filter = b"/ASCIIHexDecode"
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colorspace = b"[ /Indexed /DeviceRGB 255 <"
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filter = "/ASCIIHexDecode"
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colorspace = "[ /Indexed /DeviceRGB 255 <"
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palette = im.im.getpalette("RGB")
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for i in range(256):
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r = i8(palette[i*3])
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g = i8(palette[i*3+1])
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b = i8(palette[i*3+2])
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colorspace = colorspace + ("%02x%02x%02x " % (r, g, b)).encode('ascii')
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colorspace = colorspace + "%02x%02x%02x " % (r, g, b)
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colorspace = colorspace + b"> ]"
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procset = "/ImageI" # indexed color
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elif im.mode == "RGB":
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filter = b"/DCTDecode"
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colorspace = b"/DeviceRGB"
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filter = "/DCTDecode"
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colorspace = "/DeviceRGB"
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procset = "/ImageC" # color images
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elif im.mode == "CMYK":
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filter = b"/DCTDecode"
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colorspace = b"/DeviceCMYK"
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filter = "/DCTDecode"
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colorspace = "/DeviceCMYK"
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procset = "/ImageC" # color images
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else:
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raise ValueError("cannot save mode %s" % im.mode)
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@ -115,17 +122,17 @@ def _save(im, fp, filename):
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# catalogue
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xref[1] = fp.tell()
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_obj(fp, 1, Type = b"/Catalog",
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Pages = b"2 0 R")
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_obj(fp, 1, Type = "/Catalog",
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Pages = "2 0 R")
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_endobj(fp)
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#
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# pages
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xref[2] = fp.tell()
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_obj(fp, 2, Type = b"/Pages",
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_obj(fp, 2, Type = "/Pages",
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Count = 1,
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Kids = b"[4 0 R]")
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Kids = "[4 0 R]")
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_endobj(fp)
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#
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@ -133,7 +140,7 @@ def _save(im, fp, filename):
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op = io.BytesIO()
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if filter == b"/ASCIIHexDecode":
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if filter == "/ASCIIHexDecode":
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if bits == 1:
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# FIXME: the hex encoder doesn't support packed 1-bit
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# images; do things the hard way...
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@ -141,18 +148,18 @@ def _save(im, fp, filename):
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im = Image.new("L", (len(data), 1), None)
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im.putdata(data)
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ImageFile._save(im, op, [("hex", (0,0)+im.size, 0, im.mode)])
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elif filter == b"/DCTDecode":
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elif filter == "/DCTDecode":
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ImageFile._save(im, op, [("jpeg", (0,0)+im.size, 0, im.mode)])
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elif filter == b"/FlateDecode":
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elif filter == "/FlateDecode":
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ImageFile._save(im, op, [("zip", (0,0)+im.size, 0, im.mode)])
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elif filter == b"/RunLengthDecode":
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elif filter == "/RunLengthDecode":
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ImageFile._save(im, op, [("packbits", (0,0)+im.size, 0, im.mode)])
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else:
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raise ValueError("unsupported PDF filter (%s)" % filter)
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xref[3] = fp.tell()
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_obj(fp, 3, Type = b"/XObject",
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Subtype = b"/Image",
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_obj(fp, 3, Type = "/XObject",
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Subtype = "/Image",
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Width = width, # * 72.0 / resolution,
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Height = height, # * 72.0 / resolution,
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Length = len(op.getvalue()),
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@ -161,9 +168,9 @@ def _save(im, fp, filename):
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DecodeParams = params,
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ColorSpace = colorspace)
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fp.write(b"stream\n")
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fp.write(op.getvalue())
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fp.write(b"\nendstream\n")
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fp.write("stream\n")
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fp.fp.write(op.getvalue())
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fp.write("\nendstream\n")
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_endobj(fp)
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@ -172,37 +179,37 @@ def _save(im, fp, filename):
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xref[4] = fp.tell()
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_obj(fp, 4)
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fp.write(("<<\n/Type /Page\n/Parent 2 0 R\n"\
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fp.write("<<\n/Type /Page\n/Parent 2 0 R\n"\
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"/Resources <<\n/ProcSet [ /PDF %s ]\n"\
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"/XObject << /image 3 0 R >>\n>>\n"\
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"/MediaBox [ 0 0 %d %d ]\n/Contents 5 0 R\n>>\n" %\
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(procset, int(width * 72.0 /resolution) , int(height * 72.0 / resolution))).encode('ascii'))
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(procset, int(width * 72.0 /resolution) , int(height * 72.0 / resolution)))
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_endobj(fp)
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#
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# page contents
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op = io.BytesIO()
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op = TextWriter(io.BytesIO())
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op.write(("q %d 0 0 %d 0 0 cm /image Do Q\n" % (int(width * 72.0 / resolution), int(height * 72.0 / resolution))).encode('ascii'))
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op.write("q %d 0 0 %d 0 0 cm /image Do Q\n" % (int(width * 72.0 / resolution), int(height * 72.0 / resolution)))
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xref[5] = fp.tell()
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_obj(fp, 5, Length = len(op.getvalue()))
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_obj(fp, 5, Length = len(op.fp.getvalue()))
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fp.write(b"stream\n")
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fp.write(op.getvalue())
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fp.write(b"\nendstream\n")
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fp.write("stream\n")
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fp.fp.write(op.fp.getvalue())
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fp.write("\nendstream\n")
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_endobj(fp)
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#
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# trailer
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startxref = fp.tell()
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fp.write(("xref\n0 %d\n0000000000 65535 f \n" % len(xref)).encode('ascii'))
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fp.write("xref\n0 %d\n0000000000 65535 f \n" % len(xref))
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for x in xref[1:]:
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fp.write(("%010d 00000 n \n" % x).encode('ascii'))
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fp.write(("trailer\n<<\n/Size %d\n/Root 1 0 R\n>>\n" % len(xref)).encode('ascii'))
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fp.write(("startxref\n%d\n%%%%EOF\n" % startxref).encode('ascii'))
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fp.write("%010d 00000 n \n" % x)
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fp.write("trailer\n<<\n/Size %d\n/Root 1 0 R\n>>\n" % len(xref))
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fp.write("startxref\n%d\n%%%%EOF\n" % startxref)
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fp.flush()
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#
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