AN EXTRACTION METHOD OF DYNAMIC FEATURES IN PULSING ORGANS OF CAENORHABDITIS-ELEGANS DURING FEEDING

Caenorhabditis elegans during feeding gives good ''moving biological i mages'', in which motions of several pulsing organs are superposed on its head swing. A powerful method to extract dynamic features is prese nted. First step is to use a variance picture VAG4 in order to pick up active pixel coordinates of concerned moving objects. Superiority of VAG4 over usual variance picture VAG2 is shown quantitatively by a mod el of moving particles. Pulsing areas of C. elegans, are exhibited mor e clearly in VAG4 than VAG2. Second step is use of a new subtraction m ethod to extract main frequency bands. FFT spectra are averaged in act ive positions where VAG4 is above threshold THVR in the square with 8 X 8 pixels (ONA). The power spectra averaged in the enlarged squares ( ELA) are subtracted from those in ONA, in which ELA includes ONA in it s centre position. Large peak bands emerge in the subtracted power spe ctra, The subtraction eliminates the effect of head swing by spatial a veragings in ELA. This new emphasizing method is compared to another s ubtraction method, The characteristic frequency of periodical moving o rgans coincides well with the values observed by other research groups and our visual estimation of replayed VTR images. Thus the proposed e xtraction method is verified to work well in double superposed motions .