# Making a custom index

**URL:** <https://community.pix4d.com/t/making-a-custom-index/34329>\
**Category:** Agriculture\
**Created:** [January 18, 2026, 11:41pm UTC](https://community.pix4d.com/t/making-a-custom-index/34329 "2026-01-18T23:41:21Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![Jose.Arnaudo](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/jose.arnaudo/32/5966_2.png) [@Jose.Arnaudo](https://community.pix4d.com/u/Jose.Arnaudo)\
**Post date:** [January 19, 2026, 9:47am UTC](https://community.pix4d.com/t/making-a-custom-index/34329/2 "2026-01-19T09:47:32Z")

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hi,

You could use a masking index as mentioned in this post: [Soil and plant masking w/ Pix4Dfields](https://community.pix4d.com/t/soil-and-plant-masking-w-pix4dfields/12300)

You should use the first option:

Formula:

(nir-red)/(nir+red) + 0/max(0; (nir-red)/(nir+red) - 0.4)

Note: In this formula, using max() will mask everything lower than 0.4. This value 0.4 can be modified depending on your applications

[![](https://global.discourse-cdn.com/pix4d/original/2X/5/5c7998ecb5fc92ec22b29eef0f1ae8d368c7f912.jpeg)](https://global.discourse-cdn.com/pix4d/original/2X/5/5c7998ecb5fc92ec22b29eef0f1ae8d368c7f912.jpeg)

[1600×962 1.01 MB](https://global.discourse-cdn.com/pix4d/original/2X/5/5c7998ecb5fc92ec22b29eef0f1ae8d368c7f912.jpeg)

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