1. An apparatus for evaluating a tissue image for a medical condition, the apparatus comprising: a model predictive of the medical condition, wherein the model is based on one or more fractal dimension features from one or more binary images, each binary image corresponding to a particular color channel of the tissue image, said model defining a relationship between the expression of said one or more fractal dimension features and the medical condition, wherein the model is configured to: receive data identifying an expression of said one or more fractal dimension features within the tissue image; and evaluate said data according to the relationship defined by the model to produce a value indicative of at least one of the presence, absence, or aggressiveness of the medical condition.