Automatic caption localization in compressed video

We present a method to automatically localize captions in JPEG compressed i mages and the I-frames of MPEG compressed videos. Caption text regions are segmented from background images using their distinguishing texture charact eristics. Unlike previously published methods which fully decompress the vi deo sequence before extracting the text regions, this method locates candid ate caption text regions directly in the DCT compressed domain using the in tensity variation information encoded in the DCT domain. Therefore, only a very small amount of decoding is required. The proposed algorithm takes abo ut 0.006 second to process a 240 x 350 image and achieves a recall rate of 99.17 percent while falsely accepting about 1.87 percent nontext DCT blocks on a variety of MPEG compressed videos containing more than 2,300 I-frames .