1. A method to carry out an analysis of dimensional parameters of a structure, the method being implemented in a computer comprising a processor communicating with a memory and the method comprising: detecting, by the processor, features in a filtered image from image data of the structure, the features corresponding to domains in the structure, determining, by the processor, the co-ordinates of each feature, determining, by the processor, a critical dimension for each feature, determining, by the processor, at least one set of the features that are collinear features, fitting, by the processor, a periodic curve to the collinear features to determine the periodicity of the features, and obtaining, by the processor, placement errors for the features by comparing detected feature positions with expected positions.