Method of producing copies from photographic originals

摘要

A method for producing photographic copies (prints) from photographic originals in a photographic colour-copying (printing) apparatus comprises the following method steps: - the original is scanned in a measuring station of the photographic copying apparatus by a measurement system (12) region by region, preferably in a punctiform fashion, and the measurement light transmitted or reflected from each scanning region of the original is fed to a detector arrangement, preferably spectrally resolved and converted into electric signals which are a function of wavelength and intensity; - the data present as electric measurement signals are digitised and fed to a computing and evaluating unit for further processing; - the data are used to determine colour measurement data which are subjected in a standardising unit (16) to a reversible linear or nonlinear standardisation transformation and are converted to standardised colour values which form the input data for an analysing unit (17); - the standardised colour values are used in conjunction with consideration of properties of the original in terms of colour, density and structure to form standardised correction values in the analysing unit (17) which are independent of film; - in a destandardising unit (18) connected downstream of the analysing unit (17), the film-independent standardised correction values of the analysing unit (17) are converted by the use of a destandardisation transformation which is inverse with respect to the standardising transformation into destandardised correction values which again also take into account the colour characteristics of the film material to be copied; and - the correction values are used in an exposure calculating unit (19) to determine the required quantities of copying light or exposure corrections which are then relayed to an exposure station for producing the desired copies of the original.