1. A method of enabling touch determination based on an output signal from a touch-sensitive apparatus, the touch-sensitive apparatus comprising a panel configured to conduct signals from a plurality of peripheral incoupling points to a plurality of peripheral outcoupling points, thereby defining actual detection lines that extend across a surface portion of the panel between pairs of incoupling and outcoupling points, at least one signal generator coupled to the incoupling points to generate the signals, and at least one signal detector coupled to the outcoupling points to generate the output signal, the method comprising: processing the output signal to generate a set of data samples, wherein the data samples are indicative of detected energy for at least a subset of the actual detection lines, processing the set of data samples to generate a set of matched samples, wherein the matched samples are indicative of estimated detected energy for fictitious detection lines that have a location on the surface portion that matches a standard geometry for tomographic reconstruction, and processing the set of matched samples by tomographic reconstruction to generate data indicative of a distribution of an energy-related parameter within at least part of the surface portion.