''' MOSSE tracking sample This sample implements correlation-based tracking approach, described in [1]. Usage: mosse.py [--pause] [<video source>] --pause - Start with playback paused at the first video frame. Useful for tracking target selection. Draw rectangles around objects with a mouse to track them. Keys: SPACE - pause video c - clear targets [1] David S. Bolme et al. "Visual Object Tracking using Adaptive Correlation Filters" http://www.cs.colostate.edu/~bolme/publications/Bolme2010Tracking.pdf ''' import numpy as np import cv2 from common import draw_str, RectSelector import video def rnd_warp(a): h, w = a.shape[:2] T = np.zeros((2, 3)) coef = 0.2 ang = (np.random.rand()-0.5)*coef c, s = np.cos(ang), np.sin(ang) T[:2, :2] = [[c,-s], [s, c]] T[:2, :2] += (np.random.rand(2, 2) - 0.5)*coef c = (w/2, h/2) T[:,2] = c - np.dot(T[:2, :2], c) return cv2.warpAffine(a, T, (w, h), borderMode = cv2.BORDER_REFLECT) def divSpec(A, B): Ar, Ai = A[...,0], A[...,1] Br, Bi = B[...,0], B[...,1] C = (Ar+1j*Ai)/(Br+1j*Bi) C = np.dstack([np.real(C), np.imag(C)]).copy() return C eps = 1e-5 class MOSSE: def __init__(self, frame, rect): x1, y1, x2, y2 = rect w, h = map(cv2.getOptimalDFTSize, [x2-x1, y2-y1]) x1, y1 = (x1+x2-w)//2, (y1+y2-h)//2 self.pos = x, y = x1+0.5*(w-1), y1+0.5*(h-1) self.size = w, h img = cv2.getRectSubPix(frame, (w, h), (x, y)) self.win = cv2.createHanningWindow((w, h), cv2.CV_32F) g = np.zeros((h, w), np.float32) g[h//2, w//2] = 1 g = cv2.GaussianBlur(g, (-1, -1), 2.0) g /= g.max() self.G = cv2.dft(g, flags=cv2.DFT_COMPLEX_OUTPUT) self.H1 = np.zeros_like(self.G) self.H2 = np.zeros_like(self.G) for i in xrange(128): a = self.preprocess(rnd_warp(img)) A = cv2.dft(a, flags=cv2.DFT_COMPLEX_OUTPUT) self.H1 += cv2.mulSpectrums(self.G, A, 0, conjB=True) self.H2 += cv2.mulSpectrums( A, A, 0, conjB=True) self.update_kernel() self.update(frame) def update(self, frame, rate = 0.125): (x, y), (w, h) = self.pos, self.size self.last_img = img = cv2.getRectSubPix(frame, (w, h), (x, y)) img = self.preprocess(img) self.last_resp, (dx, dy), self.psr = self.correlate(img) self.good = self.psr > 8.0 if not self.good: return self.pos = x+dx, y+dy self.last_img = img = cv2.getRectSubPix(frame, (w, h), self.pos) img = self.preprocess(img) A = cv2.dft(img, flags=cv2.DFT_COMPLEX_OUTPUT) H1 = cv2.mulSpectrums(self.G, A, 0, conjB=True) H2 = cv2.mulSpectrums( A, A, 0, conjB=True) self.H1 = self.H1 * (1.0-rate) + H1 * rate self.H2 = self.H2 * (1.0-rate) + H2 * rate self.update_kernel() @property def state_vis(self): f = cv2.idft(self.H, flags=cv2.DFT_SCALE | cv2.DFT_REAL_OUTPUT ) h, w = f.shape f = np.roll(f, -h//2, 0) f = np.roll(f, -w//2, 1) kernel = np.uint8( (f-f.min()) / f.ptp()*255 ) resp = self.last_resp resp = np.uint8(np.clip(resp/resp.max(), 0, 1)*255) vis = np.hstack([self.last_img, kernel, resp]) return vis def draw_state(self, vis): (x, y), (w, h) = self.pos, self.size x1, y1, x2, y2 = int(x-0.5*w), int(y-0.5*h), int(x+0.5*w), int(y+0.5*h) cv2.rectangle(vis, (x1, y1), (x2, y2), (0, 0, 255)) if self.good: cv2.circle(vis, (int(x), int(y)), 2, (0, 0, 255), -1) else: cv2.line(vis, (x1, y1), (x2, y2), (0, 0, 255)) cv2.line(vis, (x2, y1), (x1, y2), (0, 0, 255)) draw_str(vis, (x1, y2+16), 'PSR: %.2f' % self.psr) def preprocess(self, img): img = np.log(np.float32(img)+1.0) img = (img-img.mean()) / (img.std()+eps) return img*self.win def correlate(self, img): C = cv2.mulSpectrums(cv2.dft(img, flags=cv2.DFT_COMPLEX_OUTPUT), self.H, 0, conjB=True) resp = cv2.idft(C, flags=cv2.DFT_SCALE | cv2.DFT_REAL_OUTPUT) h, w = resp.shape _, mval, _, (mx, my) = cv2.minMaxLoc(resp) side_resp = resp.copy() cv2.rectangle(side_resp, (mx-5, my-5), (mx+5, my+5), 0, -1) smean, sstd = side_resp.mean(), side_resp.std() psr = (mval-smean) / (sstd+eps) return resp, (mx-w//2, my-h//2), psr def update_kernel(self): self.H = divSpec(self.H1, self.H2) self.H[...,1] *= -1 class App: def __init__(self, video_src, paused = False): self.cap = video.create_capture(video_src) _, self.frame = self.cap.read() cv2.imshow('frame', self.frame) self.rect_sel = RectSelector('frame', self.onrect) self.trackers = [] self.paused = paused def onrect(self, rect): frame_gray = cv2.cvtColor(self.frame, cv2.COLOR_BGR2GRAY) tracker = MOSSE(frame_gray, rect) self.trackers.append(tracker) def run(self): while True: if not self.paused: ret, self.frame = self.cap.read() if not ret: break frame_gray = cv2.cvtColor(self.frame, cv2.COLOR_BGR2GRAY) for tracker in self.trackers: tracker.update(frame_gray) vis = self.frame.copy() for tracker in self.trackers: tracker.draw_state(vis) if len(self.trackers) > 0: cv2.imshow('tracker state', self.trackers[-1].state_vis) self.rect_sel.draw(vis) cv2.imshow('frame', vis) ch = cv2.waitKey(10) if ch == 27: break if ch == ord(' '): self.paused = not self.paused if ch == ord('c'): self.trackers = [] if __name__ == '__main__': print __doc__ import sys, getopt opts, args = getopt.getopt(sys.argv[1:], '', ['pause']) opts = dict(opts) try: video_src = args[0] except: video_src = '0' App(video_src, paused = '--pause' in opts).run()