A processing channel is operatively connected to a biometric device. The processing channel includes an analog-to-digital converter (ADC) connected to at least one of an amplifier and an offset circuit. Biometric signals representing captured biometric data, such as a fingerprint image, are controllably fitted into an input range of the ADC. The ADC input range can include one or more removed ranges and one or more adjustable allowed input ranges. One or more channel parameters are adjusted until a desired number of biometric signals are included in the one or more removed ranges.