opencv/samples/python2/feature_homography.py

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2012-10-17 01:18:30 +02:00
'''
Feature homography
==================
Example of using features2d framework for interactive video homography matching.
ORB features and FLANN matcher are used. The actual tracking is implemented by
PlaneTracker class in plane_tracker.py
Inspired by http://www.youtube.com/watch?v=-ZNYoL8rzPY
video: http://www.youtube.com/watch?v=FirtmYcC0Vc
Usage
-----
feature_homography.py [<video source>]
Keys:
SPACE - pause video
Select a textured planar object to track by drawing a box with a mouse.
'''
import numpy as np
import cv2
import video
import common
from common import getsize, draw_keypoints
from plane_tracker import PlaneTracker
class App:
def __init__(self, src):
self.cap = video.create_capture(src)
self.frame = None
self.paused = False
self.tracker = PlaneTracker()
cv2.namedWindow('plane')
self.rect_sel = common.RectSelector('plane', self.on_rect)
def on_rect(self, rect):
self.tracker.clear()
self.tracker.add_target(self.frame, rect)
def run(self):
while True:
playing = not self.paused and not self.rect_sel.dragging
if playing or self.frame is None:
ret, frame = self.cap.read()
if not ret:
break
self.frame = frame.copy()
w, h = getsize(self.frame)
vis = np.zeros((h, w*2, 3), np.uint8)
vis[:h,:w] = self.frame
if len(self.tracker.targets) > 0:
target = self.tracker.targets[0]
vis[:,w:] = target.image
draw_keypoints(vis[:,w:], target.keypoints)
x0, y0, x1, y1 = target.rect
cv2.rectangle(vis, (x0+w, y0), (x1+w, y1), (0, 255, 0), 2)
if playing:
tracked = self.tracker.track(self.frame)
if len(tracked) > 0:
tracked = tracked[0]
cv2.polylines(vis, [np.int32(tracked.quad)], True, (255, 255, 255), 2)
for (x0, y0), (x1, y1) in zip(np.int32(tracked.p0), np.int32(tracked.p1)):
cv2.line(vis, (x0+w, y0), (x1, y1), (0, 255, 0))
draw_keypoints(vis, self.tracker.frame_points)
self.rect_sel.draw(vis)
cv2.imshow('plane', vis)
ch = cv2.waitKey(1)
if ch == ord(' '):
self.paused = not self.paused
if ch == 27:
break
if __name__ == '__main__':
print __doc__
import sys
try: video_src = sys.argv[1]
except: video_src = 0
App(video_src).run()