Tonal conversion method for pictures

摘要

Disclosed herein is a tonal conversion method of a picture useful upon producing a reproduced picture such as hard or soft reproduced picture from an original picture recorded or otherwise stored on a recording medium. Tonal conversion is conducted in such a way that the pictorial information value (Xn) of a picture element on a camera subject; i.e., real picture corresponding to a desired picture element on the original picture, i.e., medium picture is obtained from a density information value (Dn) relating to the density information of the desired picture or the original picture or the medium picture, and converting the thus-obtained pictorial information value (Xn) into a tone intensity value (y) by using a specific tonal conversion formula.