A Two-Dimensional Lock-In Algorithm for Signal Analysis in Patterned Images.

Abstract

We extend a classic signal processing algorithm, the lock-in amplifier, to two dimensions to extract the signal in patterned images. The algorithm was evaluated using simulated image data and experimental microscopy images to determine the fluorescence signal of fluorescently labeled proteins adsorbed on surfaces patterned with chemical vapor deposition. The algorithm was capable of retrieving the signal with a signal-to-noise ratio as low as -20 dB. Optimal parameters were determined for the pattern design. The lock-in algorithm is a powerful technique for 1/f noise removal. The methodology holds promise not only for the measurement of adsorption events on patterned surfaces but in all situations where a signal has to be extracted from a noisy background in two or more dimensions.