A novel algorithm is proposed in this paper to detect dim moving point target with several pixels size in infrared image
sequence, taken by line scan camera in high speed moving platform, with heavy background clutter and distortion. In the
algorithm, the regional information of candidate points, which are extracted from the images after background
suppression by spatial filter, is employed to track candidate points. After tracking candidate points, the velocity of every
candidate points can be calculated easily, and false candidate points which are extracted from clutter background, can be
find out by velocity classification and removed. Then, Double Hough Transform is applied on associating the remnant
candidate points in multi-frame sequence to detect the target. The algorithm can get a high detection probability and
reduce false alarm rate dramatically.