"""
pdf2image custom buffer parsers
"""
from io import BytesIO
from typing import List
from PIL import Image
[docs]def parse_buffer_to_ppm(data: bytes) -> List[Image.Image]:
"""Parse PPM file bytes to Pillow Image
:param data: pdftoppm/pdftocairo output bytes
:type data: bytes
:return: List of PPM images parsed from the output
:rtype: List[Image.Image]
"""
images = []
index = 0
while index < len(data):
code, size, rgb = tuple(data[index : index + 40].split(b"\n")[0:3])
size_x, size_y = tuple(size.split(b" "))
file_size = len(code) + len(size) + len(rgb) + 3 + int(size_x) * int(size_y) * 3
images.append(Image.open(BytesIO(data[index : index + file_size])))
index += file_size
return images
[docs]def parse_buffer_to_pgm(data: bytes) -> List[Image.Image]:
"""Parse PGM file bytes to Pillow Image
:param data: pdftoppm/pdftocairo output bytes
:type data: bytes
:return: List of PGM images parsed from the output
:rtype: List[Image.Image]
"""
images = []
index = 0
while index < len(data):
code, size, maxval = tuple(data[index : index + 40].split(b"\n")[0:3])
size_x, size_y = tuple(size.split(b" "))
file_size = len(code) + len(size) + len(maxval) + 3 + int(size_x) * int(size_y)
images.append(Image.open(BytesIO(data[index : index + file_size])))
index += file_size
return images
[docs]def parse_buffer_to_jpeg(data: bytes) -> List[Image.Image]:
"""Parse JPEG file bytes to Pillow Image
:param data: pdftoppm/pdftocairo output bytes
:type data: bytes
:return: List of JPEG images parsed from the output
:rtype: List[Image.Image]
"""
return [
Image.open(BytesIO(image_data + b"\xff\xd9"))
for image_data in data.split(b"\xff\xd9")[
:-1
] # Last element is obviously empty
]
[docs]def parse_buffer_to_png(data: bytes) -> List[Image.Image]:
"""Parse PNG file bytes to Pillow Image
:param data: pdftoppm/pdftocairo output bytes
:type data: bytes
:return: List of PNG images parsed from the output
:rtype: List[Image.Image]
"""
images = []
c1 = 0
c2 = 0
data_len = len(data)
while c1 < data_len:
# IEND can appear in a PNG without being the actual end
if data[c2 : c2 + 4] == b"IEND" and (
c2 + 8 == data_len or data[c2 + 9 : c2 + 12] == b"PNG"
):
images.append(Image.open(BytesIO(data[c1 : c2 + 8])))
c1 = c2 + 8
c2 = c1
c2 += 1
return images