(self, image: Image.Image, config: LSBConfig)
| 12 | """LSB 输入流，按顺序从图像各像素通道的最低有效位中还原数据。""" |
| 13 | |
| 14 | def __init__(self, image: Image.Image, config: LSBConfig): |
| 15 | self.config = config |
| 16 | self.pixels = np.array(image) |
| 17 | self.height, self.width, self.channels = self.pixels.shape |
| 18 | self._bit_offset = 0 |
| 19 | |
| 20 | # 先读固定部分以获取 filename_len，再读变长文件名 |
| 21 | fixed_size = (len(LSBDataHeader.DATA_STAMP) + len(LSBDataHeader.HEADER_VERSION) |
| 22 | + LSBDataHeader.FIXED_HEADER_LENGTH + LSBDataHeader.CRYPT_ALGO_LENGTH) |
| 23 | fixed_bytes = self._read_bytes(fixed_size) |
| 24 | |
| 25 | fixed_header_offset = len(LSBDataHeader.DATA_STAMP) + len(LSBDataHeader.HEADER_VERSION) |
| 26 | filename_len = fixed_bytes[fixed_header_offset + 5] |
| 27 | |
| 28 | filename_bytes = self._read_bytes(filename_len) if filename_len > 0 else b'' |
| 29 | try: |
| 30 | self.header = LSBDataHeader.from_bytes(fixed_bytes + filename_bytes, config) |
| 31 | except Exception as e: |
| 32 | raise ValueError(f"无法解析数据头: {e}") |
| 33 | |
| 34 | self.channel_bits_used = self.header.get_channel_bits_used() |
| 35 | |
| 36 | def _read_bytes(self, n_bytes: int) -> bytes: |
| 37 | bits_per_ch = getattr(self, 'channel_bits_used', None) or self.config.get_max_bits_used_per_channel() |
nothing calls this directly
no test coverage detected