Patent ID: 9098783
Filing Date: 2015-08-04
Classification: G06T

Abstract:
1. An image reading apparatus comprising: a first illumination section arranged at a downstream side of a first image reading area in a sheet conveyance direction and configured to obliquely illuminate a first surface of a sheet in the first image reading area; a second illumination section arranged at an upstream side of the first image reading area in the sheet conveyance direction and configured to obliquely illuminate the first surface of the sheet in the first image reading area; a first reading section configured to read the first surface of the sheet illuminated in the first image reading area; an illumination switching section configured to switch between: a first two-side illumination mode in which the first image reading area is illuminated by the first illumination section and the second illumination section when the sheet is subjected to image reading in the first image reading area, and a first single-side illumination mode in which the first image reading area is illuminated by only one of the first illumination section and the second illumination section when the sheet is subjected to image reading in the first image reading area; and a determination section configured to acquire image data corresponding to the first surface of the sheet read by the first reading section in the first single-side illumination mode, identify noise relative to a background color of the sheet in the acquired image data, and determine the state of the first surface of the sheet based on the noise.