A system for analyzing remotely sensed photos of a forest or other areas of interest uses a computer system to increase the variation in NIR data having values that represent items of interest. In one embodiment, a computer system applies a stretching function to the NIR data to increase their variation. The objective spectral stretched NIR data is used to differentiate different types of vegetation in the remotely sensed image. Objective-based Vegetation Index (OVI) values are calculated from the objective spectral stretched NIR data that allow different types of vegetation to be distinguished. In one embodiment, the OVI values are used to differentiate hardwoods from conifers in a digital aerial photo of a forest.