How are ECT images calculated in view of the limited number of available measurements and the soft field problem?
in many cases, the contrast between the permittivities of the materials inside the sensor is small, resulting in only limited image distortion. This allows approximate linear algorithms to be used to relate the capacitance measurements to the pixel values in the image and vice-versa. However, if the field distortion is severe, more accurate non-linear algorithms must be used.
