We present a spline-based method for compressing and reconstructing Head-Related Transfer Functions (HRTFs) that preserves perceptual quality. Our approach focuses on the magnitude response and consists of four stages: (1) acquiring minimumphase head-related impulse responses (HRIR), (2) transforming
them into the frequency domain and applying adaptive Wiener
filtering to preserve important spectral features, (3) extracting a
minimal set of control points using derivative-based methods to
identify local maxima and inflection points, and (4) reconstructing
the HRTF using piecewise cubic Hermite interpolation (PCHIP)
over the refined control points. Evaluation on 301 subjects demonstrates that our method achieves an average compression ratio of
4.7:1 with spectral distortion ≤ 1.0 dB in each Equivalent Rectangular Band (ERB). The method preserves binaural cues with a
mean absolute interaural level difference (ILD) error of 0.10 dB.
Our method achieves about three times the compression obtained
with a PCA-based method.