A method for calibrating a printing process, comprising the steps of: a) determining a target tonal response curve for the printing process, the target tonal response curve having a function value for 0 that is non-zero or having a discontinuity between 0 and 10%; b) deriving, using curve matching, an adjustment curve that when used in the printing process matches the determined target tonal response curve in step (a), the adjustment curve comprising a basic part, a highlight part that intersects with the basic part, the highlight part derived using a 1-dimensional function having one or more input parameters selected from a limited set of options, the adjustment curve further comprising: • a starting point having a first x-value and first y-value; • a highlight curve part having a first slope at the starting point and a first intersection of the highlight curve part with a basic curve part, the first intersection having a second x-value and second y-value, the first slope and the first intersection being among the input parameters selected from the limited set of options; and • the basic curve part having a midrange point in a middle-range of the adjustment curve, the midrange point having a third x-value and a third y-value respectively greater than the second x-value and second y-value, and having a second slope at the midrange point, the basic curve part selected from a predetermined family of adjustment curves limited in number; c) adjusting one or more data values in a digital image input file by applying the selected adjustment curve to produce a digital image output file. a) determining a target tonal response curve for the printing process, the target tonal response curve having a function value for 0 that is non-zero or having a discontinuity between 0 and 10%; b) deriving, using curve matching, an adjustment curve that when used in the printing process matches the determined target tonal response curve in step (a), the adjustment curve comprising a basic part, a highlight part that intersects with the basic part, the highlight part derived using a 1-dimensional function having one or more input parameters selected from a limited set of options, the adjustment curve further comprising: • a starting point having a first x-value and first y-value; • a highlight curve part having a first slope at the starting point and a first intersection of the highlight curve part with a basic curve part, the first intersection having a second x-value and second y-value, the first slope and the first intersection being among the input parameters selected from the limited set of options; and • the basic curve part having a midrange point in a middle-range of the adjustment curve, the midrange point having a third x-value and a third y-value respectively greater than the second x-value and second y-value, and having a second slope at the midrange point, the basic curve part selected from a predetermined family of adjustment curves limited in number; • a starting point having a first x-value and first y-value; • a highlight curve part having a first slope at the starting point and a first intersection of the highlight curve part with a basic curve part, the first intersection having a second x-value and second y-value, the first slope and the first intersection being among the input parameters selected from the limited set of options; and • the basic curve part having a midrange point in a middle-range of the adjustment curve, the midrange point having a third x-value and a third y-value respectively greater than the second x-value and second y-value, and having a second slope at the midrange point, the basic curve part selected from a predetermined family of adjustment curves limited in number; c) adjusting one or more data values in a digital image input file by applying the selected adjustment curve to produce a digital image output file.