Figure 4

An example of step image frames from a non-PD control subject. (a) Step image frames from a non-PD control subject. The top panel is the original sequential walking image frames with 240 × 320 pixels. The bottom panel is the trimmed 64 × 64 pixels binary silhouettes of the top image frames. (b) The magnitudes of the associated sequential primary KPCA components. For simplicity, the primary KPCA component is denoted as ^1st KPC. The green dots indicate the magnitudes of the sequential ^1st KPCs. (c) The power spectrum of (b) using a 2048-point DFT and rectangular window with a length, L, of 64 points.