1. A document reader for reading a chromatic or achromatic document with document reading means, comprising: first identification means for inputting image information obtained from said document reading means and identifying image areas on the basis of a first identification reference value from characteristics of the image information; second identification means for determining whether the image areas are chromatic or achromatic on the basis of a second identification reference value; image processing means for performing processing for each of the image areas according to said first identification means or said second identification means; and display means for displaying the first and second identification reference values, wherein the first and second identification reference values are displayed on the same screen of said display means.