Index Map min-max values differ to the colour map legend

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

Hi

 

I have been processing some images from our multispectral camera, really trying to test and understand workflows and compare NDVI results to Sentinel 2A processed NDVI, so lots of experimenting.

I’ve attached my map which shows differing min max values between the legend and the Index Map stats, on the colour Index Map legend (and in the Colour Maps panel) min-max is -0.49 to 0.33 yet just above in the Index Map panel it shows min max as -0.55 to 0.8 (and these values show up in ArcGIS with the exported goetif).

Why is there a difference in the min max values between map legend and the Index Map stats?

Thanks

Mark Szegner

Loughborough University

2

Hi,

You can change the values in the colorbar by changing the min-max values in 4. color maps and prescription. You can have a look at the screenshot below. I have changed the min to 0.5. The colorbar now has a min value of 0.5.

3

Hi Momtanu

Thanks for your reply.

Yes, I agree this can be changed quite easily but I wanted to know why Pix4D chooses a diffferent min max value for the colour map legend and does not automatically set the legend to the real min max values, I’m curious?

Thanks, Mark

4

Hi Mark,

Thanks for asking :slight_smile:

We set a threshold and cut off the outliers (get rid of the values on the very edge of the histogram as there are very few and won’t provide any insight to the data).

5

Thanks, its all starting to make sense!