60 lines
1.5 KiB
Python
60 lines
1.5 KiB
Python
#!/usr/bin/env python3
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# ev-to-dicom
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# Copyright © 2023 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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import msgpack
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from collections import OrderedDict
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def read_ev_tlv(data: bytes):
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"""Read an Enhanced Viewer tag-length-value image payload"""
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i = 0
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def read_u16():
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nonlocal i
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i += 2
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return (data[i - 2] << 8) | data[i - 1]
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def read_u32():
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nonlocal i
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i += 4
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return (data[i - 4] << 24) | (data[i - 3] << 16) | (data[i - 2] << 8) | data[i - 1]
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metadata = OrderedDict()
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pixel_data = None
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while i < len(data):
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typ = read_u16()
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if typ == 0x0101:
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length = read_u32()
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payload = msgpack.unpackb(data[i:i+length])
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metadata.update(payload)
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i += length
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elif typ == 0x0202:
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length = read_u32()
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payload = data[i:i+length]
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pixel_data = payload
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i += length
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else:
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raise Exception('Unknown type 0x{:04x}'.format(typ))
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return metadata, pixel_data
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