Video and Image Processing Suite User Guide

ID 683416
Date 2/12/2021

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

20.4. Edge-Adaptive Scaling Algorithm

The edge-adaptive scaling algorithm is almost identical to the polyphase algorithm. It has extensions to detect edges in the input video and uses a different set of scaling coefficients to generate output pixels that lie on detected edges.

In the edge-adaptive mode, each bank of scaling coefficients inside the IP core consists of the following two full coefficient sets:

  • A set for pixels that do not lie on the edge—allows you to select a coefficient set with a softer frequency response for the non-edge pixels.
  • A set for pixels that lie on the edges—allows you to select a coefficient set with a harsher frequency response for the edge pixels.
These options potentially offer you a more favorable trade-off between blurring and ringing around edges. The Scaler II requires you to select the option to load coefficients at run time to use the edge-adaptive mode; the IP core does not support fixed coefficients set at compile time.
Note: Intel recommends that you use Lanczos-2 coefficients for the non-edge coefficients and Lanczos-3 or Lanczos-4 for the edge coefficients.