A cute little trick to running classic IIR filters on the GPU
2 days ago
- #Parallel Algorithms
- #IIR Filtering
- #GPU Computing
- The author discusses overcoming challenges in implementing an analog composite video comb + notch filter, initially hindered by excessive blurring from FIR filtering.
- Exploration of IIR filtering on GPUs, particularly using biquad IIR filters, due to their effectiveness and sharp frequency response despite being GPU-unfriendly.
- Design of a biquad IIR notch filter directly in the Z domain, placing zeroes at the chroma subcarrier frequency and poles nearby to achieve narrow band-stop filtering with minimal ringing.
- Implementation of a parallel scan algorithm on GPUs to handle IIR filters efficiently, using custom binary operators with matrices and vectors for state tracking.
- Performance results showing the filter processing frames in sub-10 microseconds, with code examples and references to shader implementations available on GitHub.