1. A system for comparing a queried character string including a wildcard character and a text image comprising: a character string image representation generator configured to embed a character string image representation of the queried character string including the wildcard into a common vectorial space based on features extracted from the queried character string including the wildcard character, the queried character string consisting of a sequence of a plurality of characters including the wildcard character, and the character string image representation including a spatial pyramid bag of characters representation including information indicating a location of the wildcard character relative to other characters included in the queried character string; a text image representation generator configured to embed a text image representation of the text image into the common vectorial space, the text image based on features extracted from the text image, and the text image including a sequence of a plurality of textual characters; a comparator configured to compute a similarity between the text image representation embedded in the common vectorial space and the character string image representation embedded in the common vectorial space; an output component configured to output information based on the computed similarity between the character string image representation embedded in the common vectorial space and the text image representation embedded in the common vectorial space; and a processor which implements the text string representation generator, text image representation generator, comparator, and output component.