[en] Causes of the non-uniformity response to a flood source and their respective importance have been studied on an image intensifier camera. To improve this response, corrections on the spatial variations of energy response and the spatial distortions due to the coordinate computation principle for this camera have been performed. These corrections are made off line, by using a data processing system, on the list mode acquisition of spatial coordinates (X,Y) and energy information (W). They have improved the uniformity index from 35% to 7% on an acquisition that was made with a 20% spectrometric window. Clinical image quality has also been improved, as these corrections allows the use of a narrower spectrometric window (20% or less)