43 lines
1.5 KiB
Python
43 lines
1.5 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
from .poppler_backend import PopplerBackend
|
|
from .ghostscript_backend import GhostscriptBackend
|
|
|
|
backends = {"poppler": PopplerBackend, "ghostscript": GhostscriptBackend}
|
|
|
|
|
|
class ImageConversionBackend(object):
|
|
def __init__(self, backend="poppler", use_fallback=True):
|
|
if backend not in backends.keys():
|
|
raise ValueError(f"Image conversion backend '{backend}' not supported")
|
|
|
|
self.backend = backend
|
|
self.use_fallback = use_fallback
|
|
self.fallbacks = list(filter(lambda x: x != backend, backends.keys()))
|
|
|
|
def convert(self, pdf_path, png_path):
|
|
try:
|
|
converter = backends[self.backend]()
|
|
converter.convert(pdf_path, png_path)
|
|
except Exception as e:
|
|
import sys
|
|
|
|
if self.use_fallback:
|
|
for fallback in self.fallbacks:
|
|
logger.info(f"Falling back on '{fallback}'")
|
|
|
|
try:
|
|
converter = backends[fallback]()
|
|
converter.convert(pdf_path, png_path)
|
|
except Exception as e:
|
|
raise type(e)(
|
|
str(e) + f" with image conversion backend '{fallback}'"
|
|
).with_traceback(sys.exc_info()[2])
|
|
continue
|
|
else:
|
|
break
|
|
else:
|
|
raise type(e)(
|
|
str(e) + f" with image conversion backend '{self.backend}'"
|
|
).with_traceback(sys.exc_info()[2])
|