A method carried out in an imaging device (512-A, 512-B, 512-C, 512-D) to transcode (856) reference encoded image data into device-specific image data, comprising the procedure the steps of: determining (852) a digital code correlation between a set of reference digital code values and a set of device specific digital code values, where the set of reference digital code values is correlated in a reference correlation with a set of reference gray levels, and where the set of device-specific digital code values correlates in a device-specific correlation with a set of device-specific gray levels; receive (854) reference encoded image data encoded with the set of reference digital code values, where the luminance values of the reference encoded image data are based on the set of reference digital code values, where a luminance difference between two reference gray levels represented by two adjacent digital reference code values of the set of digital reference code values is inversely proportional to a maximum contrast sensitivity of human vision adapted at a particular level of light; and transcoding (856), depending on the digital code correlation, the reference encoded image data encoded with the set of reference digital code values into device specific image data encoded with the set of specific digital code values of device, where the luminance values of the device-specific image data are based on the set of device-specific digital code values; characterized in that at least one of the reference correlation and the device-specific correlation is determined based on, at least in part, a functional model represented with the function ** Formula ** where D represents a digital code value that is going to correlate, L represents a gray level corresponding to the digital code value, n represents a slope in a central section of a logD / logL curve provided by the function, m represents the degree of curvature of the logD / logL curve and c1, c2 and c3 define the end and center points of the logD / logL curve.