Systems and methods for analyzing tire tread data to assess tire tread parameters, such as irregular wear characteristics of a tire tread, are provided. More particularly, an automated and robust flattening process c be performed to transform tire tread data, such as a tread surface map, into flattened tire tread data. The flattened tire tread data can provide tread heights defined in a measurement direction that is normal to the surface of the tire tread, as opposed to parallel to a radial axis of the tire. The flattened tread data can be analyzed to assess one or more parameters of the tread of the tire. For instance, local height indicators for the flattened tread data can be determined using a local maximum as a reference. Because the local height indicators are relative heights determined from a local maximum, quantification of tread depth can be more easily obtained.