Patent ID: 8649066

Claim:
An image display device, comprising: a display for displaying a preview of a document image; a display receiving unit for displaying an input screen to input a page number of the page to become the document image out of a group of the document images that will have the preview of the document image displayed with security; a reading unit for reading the group of the document images after the number is input on the input screen; a security information adding unit for adding security information indicating the image document to be displayed with security to the image document of the page that has had the page number thereof input on the input screen out of the group of the document images read by the reading unit; an image processing unit for applying an image quality degradation process to a specific area of the image document added with the security; and a preview display controlling unit for causing the image document having the image quality degradation process to be displayed if the image document is added with the security information when the preview display of the image document is displayed wherein the specific area to which the image processing unit applies the image quality degradation process is a character area of the document image; wherein the image quality degradation process applied to the character area by the image processing unit includes at least any one of a process for changing a color image in the character area into a black-and-white image, a process for reducing the resolution of the character area to a specified resolution, and a process for blurring the character area.