To provide an image reader capable of conducting an output by a proper density, in response to the kind of original and an image reading-processing program.

A mean lightness is computed by averaging the lightness of a pixel configuring a color image within a decision range (S4), and whether the mean lightness is kept within a specified range is judged (S5). When the computed mean lightness is kept within the specified range (S5:Yes), the saturations of each pixel within the decision range are acquired, and a mean saturation obtained by averaging the saturations is computed (S6). Whether the computed mean saturation is kept within the specified range is decided (S7). When the computed saturation is kept within the specified range (S7:"Yes"), the original G is decided as being a special carbon-copied one, and the image reader is set so that a conversion is carried out by using a gamma table 22c exclusive for carbon paper so as to increase the density (S8).