40 lines
1.4 KiB
Python
40 lines
1.4 KiB
Python
# pdf-segmented: Generate PDFs using separate compression for foreground and background
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# Copyright (C) 2025 Lee Yingtong Li
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Affero General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Affero General Public License for more details.
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#
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# You should have received a copy of the GNU Affero General Public License
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# along with this program. If not, see <https://www.gnu.org/licenses/>.
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from . import CompressedLayer
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from PIL import Image
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from dataclasses import dataclass
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import io
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from typing import Optional
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@dataclass
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class JP2Layer(CompressedLayer):
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data: bytes
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def jp2_compress_layer(layer: Image, jp2_lossless: bool, jp2_rate: Optional[float]) -> JP2Layer:
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save_kwargs = {}
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if jp2_rate is not None:
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save_kwargs['quality_mode'] = 'rates'
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save_kwargs['quality_layers'] = [jp2_rate]
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# Save image to JPEG 2000
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bytesio = io.BytesIO()
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layer.save(bytesio, format='jpeg2000', no_jp2=False, irreversible=not jp2_lossless, **save_kwargs)
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return JP2Layer(data=bytesio.getvalue())
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