The authors present algorithms for increasing the frame rate of an interlaced television system by a factor of 1.5. The algorithms utilize a weighted median filter structure and a simple motion detector. By adjusting the weights among the incoming fields the algorithms can be used with noninteger conversion factors. The motion detector guarantees that the performance with still pictures is optimal. The weighted median filter smoothly follows horizontal, vertical, and diagonal movement. A video sequencer was used to compare different interpolation algorithms. The proposed algorithms left few visible artifacts in the picture, and the improvement over algorithms without motion detection was particularly pronounced. The computational complexity and memory requirements of the algorithms are low. >