SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The averaging filter acts as an anti-aliasing low-pass filter for the horizontal pixel decimator. Usually, when horizontal pixel decimation is enabled (the IPIPEIF_RSZ3A[9] DECIM bit), the averaging filter must also be enabled to avoid aliasing artifacts. The averaging filter can also be used to reduce noise before H3A statistics generation. It operates on every other pixel (the same color) in a RAW Bayer input or every Y component in YCbCr data. The averaging filter can be enabled by setting the IPIPEIF_RSZ3A[8] AVGFILT bit, and it operates with the following equation:
output = (input[i – 1] + 2 × input[i] + input[i + 1]) >> 2