Image Scanner, and Method and Computer-Readable Medium Therefor

An image scanner includes a controller configured to perform black data acquiring process for each color that includes, in a particular period of time, while controlling a light source to be turned off, controlling each of a plurality of light receiving elements to read an image of an object and transmit read data of the object to a shift register, and in a specific period of time next to the particular period of time, controlling the light source to emit light of a color different from the particular color, and controlling the shift register to output a plurality of pieces of image data of the object as a plurality of pieces of black data for the particular color, the plurality of pieces of image data corresponding to the plurality of pieces of read data of the object transmitted by the plurality of light receiving elements, respectively.