A user input method and apparatus may comprise a two line object imaging sensor having a primary line scan-sensor providing a primary line scan-sensor output and a secondary line scan-sensor providing a secondary line scan-sensor output, representing pixels in a current primary scan row and a current secondary scan row, and adapted to scan an object; storing for each scan time each current primary line scan-sensor output and each current secondary line scan-sensor output and a correlation unit correlating at least one of the current representations of pixels in a primary line sensor output with stored representations and the current representations of pixels in a secondary line sensor output with stored representations and, the correlation unit providing as an output a motion indicator.