I clicked on floating point, is that correct? Yes, if you want floating point values between -1 and 1. You can also choose to scale the output to byte. When i displayed the ndvi image i got a grayscale image, is that right? Yes, NDVI is a single band result. How do i find the ndvi values of the pixels that ranges from -1 to 1 You have them if you output to floating point. Bring up the Cursor Location/Value tool to look at the data values, or calculate statistics on the file. You can use a Density Slice if you want to color code specific ranges.