Fig. 1
From: An automatic method to calculate heart rate from zebrafish larval cardiac videos
Heartbeat signals (h-signals): (a) a zebrafish larva video (ID: MVI_5280) in which each heartbeat corresponds to two brightness intensity peaks; (b) a zebrafish larva video (ID: MVI_5269) of which the zebrafish larva slid. The x-axis is frame index; the y-axis is brightness intensity of that frame. Light (the top half) and dark (the bottom half) curves indicate brightness intensities before and after, respectively, the proposed processing steps. Vertical dotted lines indicate the counting timings of the operator when he recognized a heartbeat through the video