A new CCD-based image photon counting system (IPCS) has been developed at University College London as a successor to the original Plumbicon TV based IPCS that has been used extensively at the Anglo-Australian Telescope, the Isaac Newton Telescope (La Palma), Mt.Palomar and ESO. An engineered version of the new system is currently being designed, in collaboration with the Royal Greenwich Observatory, for use on the new 4.2m William Herschel Telescope on La Palma. The prototype of this new IPCS consists of a 4-stage EMI intensifier coupled, via a high speed, custom-built lens, to an RCA thinned CCD. Photon events detected by the CCD are then centred, using "interpolative centroiding" techniques, to an accuracy of 1/8th of a CCD pixel thereby attaining high resolution. Centroided data are then accumulated in a large computer memory. Included in this new IPCS are a scanning system to even out the effects of intensifier granularity and inaccuracy of the centroiding algorithm, a frame store to remove the CCD background and any double counting, and a correction for the charge transfer inefficiency of the CCD. Also included are CRT displays for showing both the incoming signal and the integrated picture. This paper describes the new IPCS and presents details of laboratory performance tests. Such tests have demonstrated high resolution and good detection efficiency in counting incoming photons. Also included are details on future developments of this system, including the possible use of a MCP intensifier (under development) and fibre optic coupling, as well as details of expected astronomical performance.