The high pressure die casting (HPDC) process is normally referred to as the cold chamber process which solves the materials problem by separating the molten metal reservoir from the actuator for most of the process cycle. In this process, the thermal effects of molten metal flow in the die are a major factor in determining casting surface quality, die life, and many internal quality parameters such as porosity. Therefore, development of an effective technology to promptly evaluate the effect of changes in thermal process variables is vital to the quality control and improvement of productivity. Image processing technology has been applied to analyse the thermal images. The information is correlated to thermal energy stored in the die to develop a thermal control system and improve the quality of castings.