Abstract: There is provided an apparatus for estimating a necessary amount of ink for printing which comprises a reading head for scanning an original print to produce analog signals representing the optical densities of the picture dots of the original print, an A-D converter for converting the analog signal from the reading head into digital signal representing one of 256 optical density levels of the picture dot on the original print, a plurality of level counters for classifying the digital signals from the A-D converter into 256 groups each including the digital signals representing the same optical density level and counting the digital signals for each group, and a system controller for multiplying the number of digital signals in each group and the amount of ink required to print the picture dot at a corresponding optical density level to produce the total amount of ink required to print all the picture dots on the original print.