eptm_dashboard/.venv/lib/python3.12/site-packages/pypdfium2_cli/render.py

524 lines
20 KiB
Python

# SPDX-FileCopyrightText: 2026 geisserml <geisserml@gmail.com>
# SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
import os
import math
import types
import logging
import colorsys
import functools
from pathlib import Path
import multiprocessing as mp
import concurrent.futures as ft
from importlib.util import find_spec
import pypdfium2._helpers as pdfium
import pypdfium2.internal as pdfium_i
import pypdfium2.raw as pdfium_c
from pypdfium2_cli._setup import setup_logging
from pypdfium2_cli._parsers import (
add_input, get_input,
iterator_hasvalue,
BooleanOptionalAction,
)
have_pil = find_spec("PIL") is not None
have_cv2 = find_spec("cv2") is not None
logger = logging.getLogger(__name__)
def _bitmap_wrapper_foreign_simple(width, height, format, *args, **kwargs):
if format == pdfium_c.FPDFBitmap_BGRx:
use_alpha = False
elif format == pdfium_c.FPDFBitmap_BGRA:
use_alpha = True
else:
raise RuntimeError(f"Cannot create foreign_simple bitmap with bitmap type {pdfium_i.BitmapTypeToStr[format]}.")
return pdfium.PdfBitmap.new_foreign_simple(width, height, use_alpha, *args, **kwargs)
BitmapMakers = dict(
native = pdfium.PdfBitmap.new_native,
foreign = pdfium.PdfBitmap.new_foreign,
foreign_packed = functools.partial(pdfium.PdfBitmap.new_foreign, force_packed=True),
foreign_simple = _bitmap_wrapper_foreign_simple,
)
ColorSchemeFields = ("path_fill", "path_stroke", "text_fill", "text_stroke")
ColorOpts = dict(metavar="C", nargs=4, type=int)
SampleTheme = dict(
# TODO improve colors - currently it's just some random colors to distinguish the different drawings
path_fill = (170, 100, 0, 255), # dark orange
path_stroke = (0, 150, 255, 255), # sky blue
text_fill = (255, 255, 255, 255), # white
text_stroke = (150, 255, 0, 255), # green
)
def attach(parser):
add_input(parser, pages=True)
parser.add_argument(
"--output", "-o",
type = lambda p: Path(p).expanduser().resolve(),
required = True,
help = "Output directory where the serially numbered images shall be placed.",
)
parser.add_argument(
"--prefix",
help = "Custom prefix for the images. Defaults to the input filename's stem.",
)
parser.add_argument(
"--format", "-f",
type = str.lower,
help = "The image format to use (default: conditional).",
)
engines_map = {"pil": PILEngine, "numpy+pil": NumpyPILEngine, "numpy+cv2": NumpyCV2Engine}
parser.add_argument(
"--engine",
dest = "engine_cls",
type = lambda k: engines_map[k.lower()],
help = f"The saver engine to use {tuple(engines_map.keys())}",
)
parser.add_argument(
"--scale",
default = 1,
type = float,
help = "Define the resolution of the output images. By default, one PDF point (1/72in) is rendered to 1x1 pixel. This factor scales the number of pixels that represent one point.",
)
parser.add_argument(
"--rotation",
default = 0,
type = int,
choices = (0, 90, 180, 270),
help = "Rotate pages by 90, 180 or 270 degrees.",
)
parser.add_argument(
"--fill-color",
help = "Color the bitmap will be filled with before rendering. Shall be given in RGBA format as a sequence of integers ranging from 0 to 255. Defaults to white.",
**ColorOpts,
)
parser.add_argument(
"--optimize-mode",
choices = ("lcd", "print"),
help = "The rendering optimisation mode. None if not given.",
)
parser.add_argument(
"--crop",
metavar="C", nargs=4, type=float,
default = (0, 0, 0, 0),
help = "Amount to crop from (left, bottom, right, top).",
)
parser.add_argument(
"--draw-annots",
action = BooleanOptionalAction,
default = True,
help = "Whether annotations may be shown (default: true).",
)
parser.add_argument(
"--draw-forms",
action = BooleanOptionalAction,
default = True,
help = "Whether forms may be shown (default: true).",
)
parser.add_argument(
"--no-antialias",
nargs = "+",
default = [],
choices = ("text", "image", "path"),
type = str.lower,
help = "Item types that shall not be smoothed.",
)
parser.add_argument(
"--force-halftone",
action = "store_true",
help = "Always use halftone for image stretching.",
)
bitmap = parser.add_argument_group(
title = "Bitmap options",
description = "Bitmap config, including pixel format.",
)
bitmap.add_argument(
"--bitmap-maker",
choices = BitmapMakers.keys(),
default = "native",
help = "The bitmap maker to use.",
type = str.lower,
)
bitmap.add_argument(
"--grayscale",
action = "store_true",
help = "Whether to render in grayscale mode (no colors).",
)
bitmap.add_argument(
"--byteorder",
dest = "rev_byteorder",
type = lambda v: {"bgr": False, "rgb": True}[v.lower()],
help = "Whether to use BGR or RGB byteorder (default: conditional).",
)
bitmap.add_argument(
"--x-channel",
dest = "prefer_bgrx",
action = BooleanOptionalAction,
help = "Whether to prefer BGRx/RGBx over BGR/RGB (default: conditional).",
)
bitmap.add_argument(
"--maybe-alpha",
action = BooleanOptionalAction,
help = "Whether to use BGRA if page content has transparency. Note, this makes format selection page-dependent. As this behavior can be confusing, it is not currently the default, but recommended for performance in these cases.",
)
# TODO expose force_bitmap_format
parallel = parser.add_argument_group(
title = "Parallelization",
description = "Options for rendering with multiple processes.",
)
parallel.add_argument(
"--linear",
nargs = "?",
type = int,
const = math.inf,
help = "Render non-parallel if page count is less or equal to the specified value (default: 4). If this flag is given without a value, then render linear regardless of document length.",
)
parallel.add_argument(
"--processes",
default = os.cpu_count(),
type = int,
help = "The maximum number of parallel rendering processes. Defaults to the number of CPU cores.",
)
parallel.add_argument(
"--parallel-strategy",
choices = ("spawn", "forkserver", "fork"),
default = "spawn",
type = str.lower,
help = "The process start method to use. ('fork' is discouraged due to stability issues.)",
)
parallel.add_argument(
"--parallel-lib",
choices = ("mp", "ft"),
default = "mp",
type = str.lower,
help = "The parallelization module to use (mp = multiprocessing, ft = concurrent.futures).",
)
parallel.add_argument(
"--parallel-map",
type = str.lower,
help = "The map function to use (backend specific, the default is an iterative map)."
)
color_scheme = parser.add_argument_group(
title = "Flat color scheme",
description = "Options for using pdfium's color scheme renderer. Note that this may flatten different colors into one, so the usability of this is limited. Alternatively, consider post-processing with lightness inversion (see below).",
)
color_scheme.add_argument(
"--sample-theme",
action = "store_true",
help = "Use a dark background sample theme as base. Explicit color params override selectively."
)
color_scheme.add_argument("--path-fill", **ColorOpts)
color_scheme.add_argument("--path-stroke", **ColorOpts)
color_scheme.add_argument("--text-fill", **ColorOpts)
color_scheme.add_argument("--text-stroke", **ColorOpts)
color_scheme.add_argument(
"--fill-to-stroke",
action = "store_true",
help = "When rendering with custom color scheme, only draw borders around fill areas using the `path_stroke` color, instead of filling with the `path_fill` color. This is actually recommended, since with a single fill color for paths the boundaries of adjacent fill paths are less visible.",
)
postproc = parser.add_argument_group(
title = "Post processing",
description = "Options to post-process rendered images. Note, this may have a strongly negative impact on performance.",
)
postproc.add_argument(
"--invert-lightness",
action = "store_true",
help = "Invert lightness using the HLS color space (e.g. white<->black, dark_blue<->light_blue). The intent is to achieve a dark theme for documents with light background, while providing better visual results than classical color inversion or a flat pdfium color scheme. However, note that --optimize-mode lcd is not recommendable when inverting lightness.",
)
postproc.add_argument(
"--exclude-images",
action = "store_true",
help = "Whether to exclude PDF images from lightness inversion.",
)
class SavingEngine:
def __init__(self, saver_args, postproc_kwargs):
self.args = saver_args
self.postproc_kwargs = postproc_kwargs
def _get_path(self, i, ext):
args = self.args
return args.output_dir / f"{args.prefix}{i+1:0{args.n_digits}d}.{ext}"
def __call__(self, i, bitmap, page):
if self.args.maybe_alpha and self.args.format in ("jpg", "jpeg") and pdfium_c.FPDFPage_HasTransparency(page):
# alternatively, we could perhaps convert to RGB
logger.info("Page has transparency - overriding output format to PNG.")
ext = "png"
else:
ext = self.args.format
out_path = self._get_path(i, ext)
self._saving_hook(out_path, bitmap, page, self.postproc_kwargs)
logger.info(f"Wrote page {i+1} as {out_path.name}")
class PILEngine (SavingEngine):
def do_imports(self):
if not self.postproc_kwargs["invert_lightness"]:
return
logger.debug("PIL engine imports for post-processing")
global PIL
import PIL.Image
import PIL.ImageOps
import PIL.ImageFilter
import PIL.ImageDraw
_to_pil_hook = staticmethod(pdfium.PdfBitmap.to_pil)
def _saving_hook(self, out_path, bitmap, page, postproc_kwargs):
posconv = bitmap.get_posconv(page)
pil_image = self._to_pil_hook(bitmap)
pil_image = self.postprocess(pil_image, page, posconv, **postproc_kwargs)
pil_image.save(out_path)
@staticmethod
def _invert_px_lightness(r, g, b):
h, l, s = colorsys.rgb_to_hls(r, g, b)
l = 1 - l
return colorsys.hls_to_rgb(h, l, s)
LINV_LUT_SIZE = 17
@classmethod
@functools.lru_cache(maxsize=1)
def _get_linv_lut(cls):
return PIL.ImageFilter.Color3DLUT.generate(cls.LINV_LUT_SIZE, cls._invert_px_lightness)
@classmethod
def postprocess(cls, src_image, page, posconv, invert_lightness, exclude_images):
dst_image = src_image
if invert_lightness:
if src_image.mode == "L":
dst_image = PIL.ImageOps.invert(src_image)
else:
dst_image = dst_image.filter(cls._get_linv_lut())
if exclude_images:
# FIXME pdfium does not seem to provide APIs to translate XObject to page coordinates, so not sure how to handle images nested in XObjects.
# FIXME we'd also like to take alpha masks into account, but this may be difficult as long as pdfium does not expose them directly.
have_images, obj_walker = iterator_hasvalue( page.get_objects([pdfium_c.FPDF_PAGEOBJ_IMAGE], max_depth=1) )
if have_images:
mask = PIL.Image.new("1", src_image.size)
draw = PIL.ImageDraw.Draw(mask)
for obj in obj_walker:
qpoints = [posconv.to_bitmap(x, y) for x, y in obj.get_quad_points()]
draw.polygon(qpoints, fill=1)
dst_image.paste(src_image, mask=mask)
return dst_image
class NumpyPILEngine (PILEngine):
def do_imports(self):
logger.debug("NumPy+PIL engine imports")
global PIL
import PIL.Image
super().do_imports()
@staticmethod
def _to_pil_hook(bitmap):
return PIL.Image.fromarray(bitmap.to_numpy(), bitmap.mode)
class NumpyCV2Engine (SavingEngine):
def do_imports(self):
logger.debug("NumPy+cv2 engine imports")
global cv2, np
import cv2
if self.postproc_kwargs["exclude_images"]:
import numpy as np
def _saving_hook(self, out_path, bitmap, page, postproc_kwargs):
np_array = bitmap.to_numpy()
np_array = self.postprocess(np_array, bitmap, page, **postproc_kwargs)
cv2.imwrite(str(out_path), np_array)
@classmethod
def postprocess(cls, src_image, bitmap, page, invert_lightness, exclude_images):
dst_image = src_image
if invert_lightness:
if bitmap.format == pdfium_c.FPDFBitmap_Gray:
dst_image = ~src_image
else:
convert_to, convert_from = (cv2.COLOR_RGB2HLS, cv2.COLOR_HLS2RGB) if bitmap.rev_byteorder else (cv2.COLOR_BGR2HLS, cv2.COLOR_HLS2BGR)
dst_image = cv2.cvtColor(dst_image, convert_to)
h, l, s = cv2.split(dst_image)
l = ~l
dst_image = cv2.merge([h, l, s])
dst_image = cv2.cvtColor(dst_image, convert_from)
if exclude_images:
assert bitmap.format != pdfium_c.FPDFBitmap_BGRx, "Not sure how to paste with mask on {RGB,BGR}X image using cv2" # FIXME?
posconv = bitmap.get_posconv(page)
have_images, obj_walker = iterator_hasvalue( page.get_objects([pdfium_c.FPDF_PAGEOBJ_IMAGE], max_depth=1) )
if have_images:
mask = np.zeros((bitmap.height, bitmap.width, 1), np.uint8)
for obj in obj_walker:
qpoints = np.array([posconv.to_bitmap(x, y) for x, y in obj.get_quad_points()], np.int32)
cv2.fillPoly(mask, [qpoints], 1)
dst_image = cv2.copyTo(src_image, mask=mask, dst=dst_image)
return dst_image
def _render_parallel_init(logging_init, engine_init, input, password, may_init_forms, kwargs, engine):
logging_init()
logger.info(f"Initializing data for process {os.getpid()}")
engine_init()
pdf = pdfium.PdfDocument(input, password=password, autoclose=True)
if may_init_forms:
pdf.init_forms()
global ProcObjs
ProcObjs = (pdf, kwargs, engine)
def _render_job(i, pdf, kwargs, engine):
# logger.info(f"Started page {i+1} ...")
page = pdf[i]
bitmap = page.render(**kwargs)
engine(i, bitmap, page)
page.close()
def _render_parallel_job(i):
global ProcObjs
_render_job(i, *ProcObjs)
def _do_nothing(): pass
# TODO turn into a python-usable API yielding output paths as they are written
def main(args):
if not args.output.is_dir():
# make sure the output directory exists (PIL throws an error if it doesn't, but cv2 may silently skip)
raise ValueError(f"Output path is not an existing directory: {args.output!r}")
pdf = get_input(args, init_forms=args.draw_forms)
pdf_len = len(pdf)
if not all(0 <= i < pdf_len for i in args.pages):
raise ValueError("Out-of-bounds page indices are prohibited.")
if len(args.pages) != len(set(args.pages)):
raise ValueError("Duplicate page indices are prohibited.")
if args.prefix is None:
args.prefix = f"{args.input.stem}_"
if args.fill_color is None:
args.fill_color = (0, 0, 0, 255) if args.sample_theme else (255, 255, 255, 255)
if args.format is None:
# can't use jpeg with transparency rsp. when there is an alpha channel
args.format = "jpg" if args.fill_color[3] == 255 else "png"
if args.linear is None:
args.linear = 4
# numpy+cv2 is much faster for PNG, and PIL faster for JPG, but this might simply be due to different encoding defaults
if args.engine_cls is None:
assert have_pil or have_cv2, "Either pillow or numpy+cv2 must be installed for rendering CLI."
if (not have_pil) or (have_cv2 and args.format == "png"):
args.engine_cls = NumpyCV2Engine
else:
args.engine_cls = PILEngine
# PIL is faster with rev_byteorder and prefer_bgrx = True, as this achieves a natively supported pixel format. For numpy+cv2 there doesn't seem to be a difference.
if args.rev_byteorder is None:
args.rev_byteorder = issubclass(args.engine_cls, PILEngine)
if args.prefer_bgrx is None:
# PIL can't save BGRX as PNG
args.prefer_bgrx = issubclass(args.engine_cls, PILEngine) and args.format != "png"
cs_kwargs = dict()
if args.sample_theme:
cs_kwargs.update(**SampleTheme)
cs_kwargs.update(**{f: getattr(args, f) for f in ColorSchemeFields if getattr(args, f)})
color_scheme = pdfium.PdfColorScheme(**cs_kwargs) if cs_kwargs else None
kwargs = dict(
scale = args.scale,
rotation = args.rotation,
crop = args.crop,
grayscale = args.grayscale,
fill_color = args.fill_color,
optimize_mode = args.optimize_mode,
draw_annots = args.draw_annots,
may_draw_forms = args.draw_forms,
force_halftone = args.force_halftone,
rev_byteorder = args.rev_byteorder,
prefer_bgrx = args.prefer_bgrx,
maybe_alpha = args.maybe_alpha,
bitmap_maker = BitmapMakers[args.bitmap_maker],
color_scheme = color_scheme,
fill_to_stroke = args.fill_to_stroke,
)
for type in args.no_antialias:
kwargs[f"no_smooth{type}"] = True
saver_args = types.SimpleNamespace(
output_dir = args.output,
prefix = args.prefix,
n_digits = len(str(pdf_len)),
format = args.format,
maybe_alpha = args.maybe_alpha,
)
postproc_kwargs = dict(
invert_lightness = args.invert_lightness,
exclude_images = args.exclude_images,
)
if args.invert_lightness and args.optimize_mode == "lcd":
logger.warning("LCD optimization clashes with lightness inversion, as post-processing colors defeats the idea of subpixel rendering.")
print_args = vars(args).copy()
del print_args["subcommand"], print_args["pages"]
if print_args["password"]:
print_args["password"] = "<obfuscated>"
logger.debug(f"{print_args}") # TODO prettier?
if color_scheme:
logger.debug(f"{color_scheme}")
engine = args.engine_cls(saver_args, postproc_kwargs)
if len(args.pages) <= args.linear:
logger.info("Linear rendering ...")
engine.do_imports()
for i in args.pages:
_render_job(i, pdf, kwargs, engine)
else:
logger.info("Parallel rendering ...")
ctx = mp.get_context(args.parallel_strategy)
pool_backends = dict(
mp = (ctx.Pool, "imap"),
ft = (functools.partial(ft.ProcessPoolExecutor, mp_context=ctx), "map"),
)
pool_ctor, map_attr = pool_backends[args.parallel_lib]
if args.parallel_map:
map_attr = args.parallel_map
if args.parallel_strategy == "fork":
logging_init, engine_init = _do_nothing, _do_nothing
engine.do_imports()
else:
logging_init, engine_init = setup_logging, engine.do_imports
pool_kwargs = dict(
initializer = _render_parallel_init,
initargs = (logging_init, engine_init, pdf._input, args.password, args.draw_forms, kwargs, engine),
)
n_procs = min(args.processes, len(args.pages))
with pool_ctor(n_procs, **pool_kwargs) as pool:
map_func = getattr(pool, map_attr)
for _ in map_func(_render_parallel_job, args.pages):
pass