How to retrieve The Red-Edge Inflection Point Index (REIP) using SNAP?

[neteler]

Maybe interesting here (comment from 2019):

REIP processor

In the REIP operator there is an obvious error. For Sentinel-2 the used formula is stated to be: 700 + 40 * ((B4 + B7)/2 - B5) / (B6 - B5), which is valid for interpolation between 700 nm and 740 nm (as introduced by Guyot and Baret, 1988). However, Sentinel-2 bands are at 705 nm and 740 nm, thus the formula must be: 705 + 35 * ((B4 + B7)/2 - B5) / (B6 - B5). Jan Clevers (Wageningen University)