Errors due to quantization in MTF determination using sinusoidal targets

Abstract

A theoretical treatment of the effect of quantization upon the determination of modulation transfer functions (MTF) of digital acquisition devices is initially developed for a noiseless system, when using sinusoidal targets. The analytical work shows that a component due to quantization exists in the measured MTF which increases as the bitdepth of the quantization and the amplitude of the input signal decrease. An expression to estimate this component from parameters describing the input signal and quantizer is derived. Modifications are made to account for quantization and input signal noise, yielding new estimates of the component for single measurements. The estimates were experimentally tested using an analogue-to-digital converter (ADC).