A printhead controller controls printing of a page by at least one printhead. The printhead controller is connected, in use, via a data communications link to a printer controller for receiving data, in a compressed format relating to the page to be printed, the data including a page description comprising a bi-level black layer and a contone color layer. The printhead controller includes a first decoder for expanding compressed data relating to the bi-level black layer and a second decoder for expanding compressed data relating to the contone color layer. The first and second decoders are arranged in parallel. First and second temporary storage devices are provided for storing the expanded data from the first and second decoders, respectively. A data manipulating unit manipulates the data output from these temporary storage devices to be fed to the printhead. A printhead interface is provided at an output from the data manipulator for controlling at least one printhead connectable to the interface and for feeding the manipulated data to the printhead.