Patent ID: 8199366

Claim:
An image reading apparatus which reads images in a front side and a back side of a document by passing the document through the image reading apparatus once, comprising: a first reading section to read the front side of the document; a second reading section to read the back side of the document; a storage section to store a first standard value for carrying out a first shading correction to the first reading section and a second standard value for carrying out a second shading correction to the second reading section; and an image process section to carry out the first shading correction to a first image data read by the first reading section based on the first standard value and to carry out the second shading correction to a second image data read by the second reading section based on the second standard value, wherein the storage section stores a table in which the first read value obtained by the first reading section reading a chart and the second read value obtained by the second reading section reading the chart and a standard value are respectively related to one another, and the image process section calculates the first standard value based on the first read value obtained by the first reading section reading the chart and the table stored in the storage section, and calculates the second standard value based on the second read value obtained by the second reading section reading the chart and the table stored in the storage section.