Wrong NDVI scale

[obw]

Hi there.

I'm struggling a bit to get the correct scale for my NDVI Pictures.

I can't  understand the "Palette" page in the raster page.  It seems you manually have to adjust the palette to corresond with the correct colors on the NDVI scale between -1 and +1, and not use the auto function. If you use the auto function, the colors on the scale does not allign with the correct values. Then what is the point with the auto function?

Basically what I want is to export a correct color scale that can be used with the exported NDVI orthomosaic.

Ben

[obw]

I'm attaching some example pictures clarify my point.

- The manual Picture: As you can see I have adjusted the palette manually to correspond With the colors. The scale corresponds With the colors.

- The auto Picture: The palette range is automatically adjusted, but the color scale remains identical. So basically all the colors in the image changes but the scale remains the same.

Looking forward to your response.

- Ben

[Alexey Pasumansky]

Hello Ben,

The Range values defines the interval where Palette is applied.

When the palette is applied Range-start is treated and "zero" value of the palette and Range_end is related to "one" value of the palette. So the palette frame shouldn't change depending on the range interval or any other factors - it defines how the index values are represented in the Ortho view mode.

So for correct NDVI representation you'll need to use Range interval [0; 1] and leave Palette as default.

[obw]

Thank you very much, this was exactly the information I was looking for!

[obw]

Hi again.

Just bringing this post back up for a follow up question.

Is there any way to have a transparent color in the palette raster calculator for a certain value, or just don't let it create a palette for the values that is not specified?

I.e I want all values below 0 to not be "colorized", but just the values above 0. This way roads, buildings etc. does not have raster calculated, but only vegetation.

[Alexey Pasumansky]

Hello obw,

Currently it is not possible to add transparency parameter to certain color, however, we already have similar requests and will try to implement such functionality in version 1.4.

[obw]

Sounds very good, thank you!