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TGI index in Mapper

Hello, I have seen the TGI formula for Pix4D Fields and a comment in the Fields Support regarding a formula.
I am in mapper, in Index Map and the TGI formula Rgreen - 0.39 * RRED - 0.61* RBLUE that you mention in Fields, does not work.
How do I enter the “normalized to the maximum value of RED, GREEN and BLUE bands”?
Thank you

Hi @jzanelli, Pix4DMapper does not have the min, max functions in the calculator. You will need to use QGIS/ArcGIS or any raster calculator that has these functions. You could also do the same in any programming language. This is how we normalize: we compute the maximum pixel value in the image for the three bands involved. So the formula is (G - 0.39 * R - 0.61 * B) / image_maxpixelvalue(R, G, B)

Ok will do