Calibrating NDVI Images in Fiji (ImageJ)

Today we are proud to announce a new work-flow for calibrating your captured NDVI survey images to produce normalized gradient maps. This is a huge step in providing affordable, turn-key imaging that can be compared with surveys performed over time and in different parts of the world.

For the full details please read our post HERE.

Original NDVI MAPIR stitched image of a golf course:

Calibrated image with a Black (0) to White (1) lut applied:

MAPIR_ndvi_0-1 lut applied:

 MAPIR_ndvi_0-1_CB lut applied:

When you look at the above images, here are a few good things to keep in mind when using our luts:

  • Healthy vegetation shows up as a shade of green, with the darker the shade the healthier it is
  • As you go lower in NDVI value, and go from the yellow to orange, to red colors (or to purples if using the color-blind lut) the vegetation will be getting less healthy.
  • Pure white is right around the border of no vegetation and bare soil, so just assume no plants are there.
  • The gray-scale areas will be bodies of water, roads, buildings and other non-vegetation
  • Any blue areas will typically be areas of shaded vegetation which is difficult to assess the health (a reason it's ideal to capture images when the sun is highest in the sky if possible)

Here are some more examples using the MAPIR_ndvi_0-1 lut:

Nolan Ramseyer
Nolan Ramseyer