rVision Optical Flow Demo

rVisionOpticalFlowDemo.R

library(Rvision)
library(tidyverse)

vid_loc <- paste0(find.package("Rvision"), "/sample_vid/SampleVideo_1080x720_5mb.mp4")
vid1 <- video(vid_loc)

res <- data.frame(frame_pos = seq(2,nframes(vid1), 5), total_movement = NA)

old <- readFrame(vid1, 1)

pb <- txtProgressBar(min = 0, max = nrow(res), style = 3)

for(i in 1:nrow(res)) {
	new <- readFrame(vid1, res$frame_pos[i])
	of <- farneback(old, new, winsize = 61)
	d <- sqrt(of[, , 1]^2 + of[, , 2]^2)
	res$total_movement[i] <- sum(d)
	old <- cloneImage(new)
	setTxtProgressBar(pb, i)
}

close(pb)

ggplot(res, aes(x=frame_pos, y = total_movement, group=1)) + geom_path()