[QUOTE]art23130 wrote In fact Many factors affect NDVI values like plant photosynthetic activity, total plant cover, biomass, plant and soil moisture, and plant stress and there are a lot of factors that influence the relationship between NDVI and rangeland ecosystem attributes which include: atmospheric conditions, etc … although it is a popular method. I think for extracting vegetative cover you shoudl consider some other factors along NDVI but if you want to use just NDVI you can mask the values below 0 which is pretty simple in ENVI. you can use interactive stretching and set the min value to 0 so you can stretch your data between 0-1. you do not need to convert your data just use ENVI extension for ArcGIS and import your NDVI as a raster file, I think this is the proper way to use it in ArcGIS. I hope it helps. :) [/QUOTE] Thank you very much art23130 for your sincere concern. Actually I am just a beginner with ENVI, so, please could you let me know in more details; how can I extract the vegetation cover by masking the values >0 of the NDVI image? Thanks a lot again in advance.

Thank you very much.

Thanks a lot for your concern, but, sorry, it still unclear. Actually, I hope someone could help me to explain how can I extract the vegetation cover by masking the values >0 of the NDVI image by using ENVI 4.8; step by step. Thanks a lot in advance.

Kindly, any contribution will be highly appreciated.

no reply??!!

Try Basic Tools ->Masking->Build Mask. Select the display of your image. Then use Options ->Import Data range and select the range of values to use for the mask.