1. Process for enhancing detail visibility in a digital input image comprising: a step of applying a first transfer function ( 11 ) operating as a knee function ( 11 ) to the digital input image, thereby generating an intermediate image; a step of performing a first statistical measurement ( 12 , Mmt 2 ) on the intermediate image; a step of applying a second transfer function ( 14 ) operating as a gamma function ( 14 ) to the intermediate image, thereby generating an output image; a step of performing a second statistical measurement ( 15 , Mmt 3 ) on the output image, a step of determining gain parameters (gg, gk) for the first and the second transfer function ( 11 , 14 ) on basis of results of the first and second statistical measurements ( 12 , 15 , Mmt 2 , Mmt 3 ).