14. A computer-implemented method for generating a global image representation of a text image, the method comprising: a) extracting a plurality of image patch descriptors representative of a plurality of respective image patches representative of the text image, the plurality of image patches including a background area and a foreground area associated with the text image; b) computing a plurality of aggregated representations of the image patch descriptors, each aggregated representation associated with an image block including two or more image patches; c) determining character annotations associated with each image block by projecting each image block's aggregated representation computer in step b) into an intermediate subspace associated with training text images including one or more annotated character bounding boxes, the intermediate subspace mapping visual features to a semantic space; and d) associating the determined character annotation with each respective image block associated with the text image to generate the global image representation of the text image.
14. A computer-implemented method for generating a global image representation of a text image, the method comprising: a) extracting a plurality of image patch descriptors representative of a plurality of respective image patches representative of the text image, the plurality of image patches including a background area and a foreground area associated with the text image; b) computing a plurality of aggregated representations of the image patch descriptors, each aggregated representation associated with an image block including two or more image patches; c) determining character annotations associated with each image block by projecting each image block's aggregated representation computer in step b) into an intermediate subspace associated with training text images including one or more annotated character bounding boxes, the intermediate subspace mapping visual features to a semantic space; and d) associating the determined character annotation with each respective image block associated with the text image to generate the global image representation of the text image. 17. The computer-implemented method for generating a global image representation of a text image according to claim 14 , wherein step b) and step c2) encodes the image blocks using FV over SIFT descriptors with a spatial pyramid.