ca1582a839
Implement phash_glyph(bitmap: &[u8; 1024]) -> u64 that computes a 64-bit perceptual hash for 32×32 grayscale glyph bitmaps. Algorithm: 1. Normalize pixel values to [-1.0, +1.0] 2. Apply 32×32 2D DCT-II (hand-rolled, precomputed basis) 3. Extract 64 low-frequency AC coefficients (8×8 block, DC excluded) 4. Threshold against median to produce 64-bit hash Key features: - Special case for uniform bitmaps (returns 0 deterministically) - Deterministic across platforms (no NaN, stable float ordering) - hamming_distance helper for hash comparison Closes: pdftract-47vu |
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| .. | ||
| pdftract-cer-diff | ||
| pdftract-cli | ||
| pdftract-core | ||
| pdftract-libpdftract | ||
| pdftract-py | ||