Specification and Control of Process Color Images by Direct Colorimetric Measurement

Through use of area integration and positioning references, selected segments of color images are colorimetrically measured. Resulting tristimulus color scale values are suitable for specification and communication of target image colors and acceptability tolerances. Where separations have been made and paper and inks for reproduction selected, quantitative corrections in effective influence of specific inks are derived from the colorimetric measurements of samples compared with those of the target. These adjustments are useful at all color correction steps in the process where evaluation and changes can be made. By reducing correction errors or omissions, cost savings can be realized in preparing and achieving balance in separations and the plates or cylinders prepared from them as well as in reducing the spread of variations during press runs.