PICTURE PROCESSING METHOD

摘要

PROBLEM TO BE SOLVED: To obtain optimum picture quality by multiplying the change of a picture value by a coefficient based on an average picture value in a window in the periphery of an objective picture element in an original picture and/or the dispersion of the picture value and the picture value itself. SOLUTION: The picture values of respective picture elements in a detailed picture Si are converted in a block 21 having a non-linear conversion characteristic. A conversion processing is executed by using a look-up table where the respective picture values of the detailed picture Si as input are related to the picture value of a conversion picture Sei which is possible as output. In a block 22, a difference is detected between the picture value as the output of the block 21 and the picture value of the objective picture element in the detailed picture Si. In a multiplication block 23, the difference is multiplied by the coefficient (b) of 0-1. The coefficient (b) is decided from the picture having a value matched with average lightness in an objective position on the respective picture elements of the detailed picture Si. At that time, the original picture Ii-1 of the detailed picture Si can be used since it has the totally similar number of picture elements as that of the detailed picture Si.