Patent ID: 7949155

Claim:
An image processing apparatus comprising: an image memory that stores an image corresponding to each page of a document and obtained by scanning the document; a character recognition rate acquisition unit that segments the image stored in the image memory into a plurality (n) of partial images and acquires a character recognition rate for each partial image; an image quality assessment unit that calculates a parameter showing the image quality of the image for said each page, based on the character recognition rates of the plurality of partial images acquired by the character recognition rate acquisition unit, and decides whether a scanning error is present by comparing the parameter with a threshold value; and an output unit that outputs a number of a page containing the scanning error, and an assessment result determined based on the parameter, and also outputs a message inquiring as to whether re-scanning is necessary if the image quality assessment unit decides that the scanning error is present, wherein the parameter is calculated using the formula: Qs =1−(α max −α max ) or Qs =α min /α max where a α max and α min are maximum and minimum values of character recognition rate α i for each partial image, and Qs is a real number satisfying the condition 0≦Qs≦1, the character recognition rate a, is normalized using the formula: β i = α i ∑ i n ⁢ α i , and the parameter is alternatively calculated using the formula: Q s = - ∑ i n ⁢ β i ⁢ log ⁢ ⁢ β i - ∑ i n ⁢ 1 n ⁢ log ⁢ ⁢ 1 n .