Disclosed are systems and methods for determining the logarithmic transfer function of a plurality of analog signals using digital circuitry components. The apparatus is a digital crystal video receiver that includes an analog-to-digital converter and a programmable logic component that determines the logarithmic transfer function of plurality of signals. The programmable logic component may include a FPGA, microprocessor, macroprocessor, combinations of discrete logic components, etc. The programmable logic component includes memory having one of a look-up table and an instruction set that enables the programmable logic component to process or calculate a signal that is logarithmically proportional to the plurality of signals. The method for determining the logarithmic transfer function of a plurality of analog signals comprises converting the plurality of analog signals to a plurality digital signals and determining the logarithmic transfer function of the plurality of analog signals via a programmable logic component.