1. A method for measuring quality of a biometric image comprising: converting a biometric image to dimensionless image data; filtering the dimensionless image data with a band pass filter; applying a sliding window to the filtered dimensionless image data to identify portions for information distance calculations; generating an information distance for the portions of the filtered data identified by the sliding window; weighting information distances for selected portions identified by the sliding window; ranking the weighted information distances; selecting a number N portions corresponding to the N weighted information distances that are larger than the other weighted information distances in the ranking of the weighted information distances to identify a plurality of portions in the filtered dimensionless image data as containing identification features; and measuring clarity for the biometric image from the identified plurality of portions in the filtered dimensionless image data.