A gridding Hough transform for detecting the straight lines in sports video

A gridding Hough transform (GHT) is proposed to detect the straight lines in sports video, which is much faster and requires much less memory than the previous Hough transforms. The GHT uses the active gridding to replace the random point selection in the random Hough transforms because forming the linelets from the actively selected points is easier than from the randomly selected points. Existing straight-line Hough transforms require a lot of resources because they were designed for all kinds of straight lines. Considering the fact that the straight lines interested in sports video are long and sparse, this paper proposes two techniques: the active gridding and linelets process. On account of these two techniques, the proposed GHT is fast and uses little memory. The experimental results show that the proposed GHT is faster than the random Hough transform (RHT) and the standard Hough transform (SHT) by 30% and 700% respectively and achieves a 97.5% recall, higher than those achieved by either the SHT or the RHT.