2. The image processing apparatus of claim 1 , wherein the processor is further configured to: calculate a first absolute value group of differences between the similarity degrees included in the first similarity degree group and the similarity degrees included in the second similarity degree group, in units of a corresponding digit between the first character string and the second character string and in units of a candidate character in the candidate character group, calculate a first sum value of a sum of all absolute values in the first absolute value group, calculate a second absolute value group of differences between the similarity degrees included in the first similarity degree group and the similarity degrees included in the third similarity degree group, in units of a corresponding digit between the first character string and the third character string and in units of a candidate character in the candidate character group, calculate a second sum value of a sum of all absolute values in the second absolute value group, determine that the second character string corresponds to the first subject which is identical to the first character string if the first sum value is smaller than the second sum value, and determine that the third character string corresponds to the first subject which is identical to the first character string if the second sum value is smaller than the first sum value.
1. An image processing apparatus comprising: an interface configured to receive, from an external apparatus, a first image and a second image, wherein the first image is different from the second image; and a processor configured to: extract a first character string appearing on the first image, and a second character string and a third character string appearing on the second image, cut out each of characters constituting the first character string, in units of a character, cut out each of characters constituting the second character string, in units of a character, and cutting out each of characters constituting the third character string, in units of a character, calculate a first similarity degree group which is composed of similarity degrees between the respective characters constituting the first character string and respective candidate characters in a candidate character group, calculate a second similarity degree group which is composed of similarity degrees between the respective characters constituting the second character string and the respective candidate characters in the candidate character group, calculate a third similarity degree group which is composed of similarity degrees between the respective characters constituting the third character string and the respective candidate characters in the candidate character group, and determine which of the second character string and the third character string corresponds to a first subject which is identical to the first character string, by comparing the first similarity degree group with the second similarity degree group and the third similarity degree group.