1. A method for efficient image-based indexing and classification in an image database using digital hardware, software or firmware or combinations thereof, the method comprising: selecting one or more representative images; identifying features of the one or more representative images; defining classifier parameters from the identified features, wherein defining classifier parameters from the identified features comprises: determining the discrimination ability of each feature; determining the variance of each feature; and determining the spatial variance of components; comparing the classifier parameters to at least a plurality of document images within the image database to obtain a reduced set of candidate images selected from the at least a plurality of document images; and indexing or classifying the reduced set of candidate images.