An integration circuit divides a screen, which is composed of an input video signal, into regions, integrates absolute values of inter-field differences that are included the respective regions, and provides an intra-region integration value SDA. The apparatus, methods, and programs may store a plurality of types of past traffic information, each type of past traffic information having a priority and may merge the stored past traffic information in accordance the priorities. The compacting means may together with the supply roller pair form a drawing zone for the fiber fleece web. The power supply control circuit determines that the short-circuit fault is generated, when the reference voltage VD is more than the threshold value VrefL and a switching control signal is in an ON state. Even by the use of a catheter having a small outside diameter, therefore, the apparatus is enabled to effect powerful laser irradiation without being thermally affected by the laser beam and consequently shatter thrombus, for example, and recover by aspiration the shattered thrombus through the distal end of the catheter. The system includes a light generating means for projecting a light beam onto the top surface of the workpiece at a predetermined angle and a video capturing means for detecting the light received by the workpiece.