IntDelta

The IntDelta transform computes an intra-plane, element-wise integer subtraction between consecutive values.

Theory

Unlike XorDelta which operates against a reference tensor, IntDelta operates purely within the single plane. Each element is replaced by its integer difference from its predecessor: out[i] = in[i].wrapping_sub(in[i-1]).

For smoothly-varying data (such as sorted indices or certain numerical embeddings), the adjacent values are numerically close. The resulting delta stream concentrates values near zero, which downstream entropy coders (like FPC or Arithmetic) can compress much more effectively than the raw bytes. The element width determines the wrapping arithmetic boundary (e.g., 1, 2, 4, or 8 bytes).

Inverse

The inverse operation simply computes a running wrapping addition: in[i] = out[i].wrapping_add(in[i-1]).

References

• Generic Delta Encoding. Wikipedia