1. A computer system for producing an image in which conifers can be distinguished from hardwoods in a region of interest, comprising: a computer readable memory for storing programmed instructions that can be executed by a processor; one or more processors that are configured to execute the programmed instructions in order to: receive digital aerial image data for a region of interest including data in at least a near infrared (NIR) spectral band, a red spectral band and a green spectral band; stretch the near infrared (NIR) spectral band data by defining NIR spectral band data having values that are less than a threshold NIR value selected to eliminate unwanted land covers/uses in the digital aerial image as having a zero value and by mapping NIR spectral band data having values that are greater than the threshold NIR value into a larger output range of NIR values to increase a variation of NIR values that represent vegetation in the digital aerial image; apply the stretched NIR spectral band data to one of a red, green or blue channel and the red spectral band data to another of the red, green or blue channel and the green spectral data to another of the red, green or blue channel to define a number of colored pixels; compute objective vegetation index (OVI) values at locations corresponding to the colored pixels by dividing the stretched NIR spectral band data at each pixel location by the red spectral band data at the same pixel location; determine a color for each OVI value based on the average color of the colored pixels that correspond to the same OVI value; and produce a color image of the OVI values with their respective colors in which conifers can be distinguished from hardwoods in the region of interest.