Abstract: A plurality of reference points (P.sub.1 -P.sub.5) are selected on an original image. The respective color density levels of the reference points are simultaneously displayed on the CRT (64). The operator sets up the image processor while monitoring the respective color density levels on the CRT.

Abstract: A color scanner capable of displaying a plurality of images in parallel comprises a scanning head for scanning a plurality of images for inputting image signals thereof; a first memory for storing image signals of the plurality of images inputted by the scanning head; a color correction circuit for correcting image signals stored in the first memory to set desired conditions for reproduction; an output skipping circuit for reducing the number of image signals corrected by the color correction circuit to a predetermined number so that they can be displayed on a color monitor; a second memory for storing image signals of the plurality of images skipped by the output skipping circuit; and a color monitor for simultaneously displaying on one screen the plurality of images corrected, based on the image signals stored in the second memory.

Abstract: Basic data obtained by thinning-out data to be written in a look-up table are previously operated by a computer and stored in a basic memory table. Coefficient data required for linearly interpolating the basic data are stored in a coefficient memory table. The basic data and the coefficient data are read in accordance with address designation by an address generator while being related with each other and subjected to interpolation operation by an interpolation computer element, and data thus obtained are sequentially written in the look-up table.