new/improved Python samples by Alexander Mordvintsev

pull/7/merge
Vadim Pisarevsky 12 years ago
parent 2c2d6fa5fd
commit 2013118971
  1. 412
      samples/python2/common.py
  2. 256
      samples/python2/feature_homography.py
  3. 103
      samples/python2/plane_ar.py
  4. 171
      samples/python2/plane_tracker.py

@ -1,200 +1,212 @@
import numpy as np
import cv2
import os
from contextlib import contextmanager
import itertools as it
image_extensions = ['.bmp', '.jpg', '.jpeg', '.png', '.tif', '.tiff', '.pbm', '.pgm', '.ppm']
def splitfn(fn):
path, fn = os.path.split(fn)
name, ext = os.path.splitext(fn)
return path, name, ext
def anorm2(a):
return (a*a).sum(-1)
def anorm(a):
return np.sqrt( anorm2(a) )
def homotrans(H, x, y):
xs = H[0, 0]*x + H[0, 1]*y + H[0, 2]
ys = H[1, 0]*x + H[1, 1]*y + H[1, 2]
s = H[2, 0]*x + H[2, 1]*y + H[2, 2]
return xs/s, ys/s
def to_rect(a):
a = np.ravel(a)
if len(a) == 2:
a = (0, 0, a[0], a[1])
return np.array(a, np.float64).reshape(2, 2)
def rect2rect_mtx(src, dst):
src, dst = to_rect(src), to_rect(dst)
cx, cy = (dst[1] - dst[0]) / (src[1] - src[0])
tx, ty = dst[0] - src[0] * (cx, cy)
M = np.float64([[ cx, 0, tx],
[ 0, cy, ty],
[ 0, 0, 1]])
return M
def lookat(eye, target, up = (0, 0, 1)):
fwd = np.asarray(target, np.float64) - eye
fwd /= anorm(fwd)
right = np.cross(fwd, up)
right /= anorm(right)
down = np.cross(fwd, right)
R = np.float64([right, down, fwd])
tvec = -np.dot(R, eye)
return R, tvec
def mtx2rvec(R):
w, u, vt = cv2.SVDecomp(R - np.eye(3))
p = vt[0] + u[:,0]*w[0] # same as np.dot(R, vt[0])
c = np.dot(vt[0], p)
s = np.dot(vt[1], p)
axis = np.cross(vt[0], vt[1])
return axis * np.arctan2(s, c)
def draw_str(dst, (x, y), s):
cv2.putText(dst, s, (x+1, y+1), cv2.FONT_HERSHEY_PLAIN, 1.0, (0, 0, 0), thickness = 2, lineType=cv2.CV_AA)
cv2.putText(dst, s, (x, y), cv2.FONT_HERSHEY_PLAIN, 1.0, (255, 255, 255), lineType=cv2.CV_AA)
class Sketcher:
def __init__(self, windowname, dests, colors_func):
self.prev_pt = None
self.windowname = windowname
self.dests = dests
self.colors_func = colors_func
self.dirty = False
self.show()
cv2.setMouseCallback(self.windowname, self.on_mouse)
def show(self):
cv2.imshow(self.windowname, self.dests[0])
def on_mouse(self, event, x, y, flags, param):
pt = (x, y)
if event == cv2.EVENT_LBUTTONDOWN:
self.prev_pt = pt
if self.prev_pt and flags & cv2.EVENT_FLAG_LBUTTON:
for dst, color in zip(self.dests, self.colors_func()):
cv2.line(dst, self.prev_pt, pt, color, 5)
self.dirty = True
self.prev_pt = pt
self.show()
else:
self.prev_pt = None
# palette data from matplotlib/_cm.py
_jet_data = {'red': ((0., 0, 0), (0.35, 0, 0), (0.66, 1, 1), (0.89,1, 1),
(1, 0.5, 0.5)),
'green': ((0., 0, 0), (0.125,0, 0), (0.375,1, 1), (0.64,1, 1),
(0.91,0,0), (1, 0, 0)),
'blue': ((0., 0.5, 0.5), (0.11, 1, 1), (0.34, 1, 1), (0.65,0, 0),
(1, 0, 0))}
cmap_data = { 'jet' : _jet_data }
def make_cmap(name, n=256):
data = cmap_data[name]
xs = np.linspace(0.0, 1.0, n)
channels = []
eps = 1e-6
for ch_name in ['blue', 'green', 'red']:
ch_data = data[ch_name]
xp, yp = [], []
for x, y1, y2 in ch_data:
xp += [x, x+eps]
yp += [y1, y2]
ch = np.interp(xs, xp, yp)
channels.append(ch)
return np.uint8(np.array(channels).T*255)
def nothing(*arg, **kw):
pass
def clock():
return cv2.getTickCount() / cv2.getTickFrequency()
@contextmanager
def Timer(msg):
print msg, '...',
start = clock()
try:
yield
finally:
print "%.2f ms" % ((clock()-start)*1000)
class StatValue:
def __init__(self, smooth_coef = 0.5):
self.value = None
self.smooth_coef = smooth_coef
def update(self, v):
if self.value is None:
self.value = v
else:
c = self.smooth_coef
self.value = c * self.value + (1.0-c) * v
class RectSelector:
def __init__(self, win, callback):
self.win = win
self.callback = callback
cv2.setMouseCallback(win, self.onmouse)
self.drag_start = None
self.drag_rect = None
def onmouse(self, event, x, y, flags, param):
x, y = np.int16([x, y]) # BUG
if event == cv2.EVENT_LBUTTONDOWN:
self.drag_start = (x, y)
if self.drag_start:
if flags & cv2.EVENT_FLAG_LBUTTON:
xo, yo = self.drag_start
x0, y0 = np.minimum([xo, yo], [x, y])
x1, y1 = np.maximum([xo, yo], [x, y])
self.drag_rect = None
if x1-x0 > 0 and y1-y0 > 0:
self.drag_rect = (x0, y0, x1, y1)
else:
rect = self.drag_rect
self.drag_start = None
self.drag_rect = None
if rect:
self.callback(rect)
def draw(self, vis):
if not self.drag_rect:
return False
x0, y0, x1, y1 = self.drag_rect
cv2.rectangle(vis, (x0, y0), (x1, y1), (0, 255, 0), 2)
return True
@property
def dragging(self):
return self.drag_rect is not None
def grouper(n, iterable, fillvalue=None):
'''grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx'''
args = [iter(iterable)] * n
return it.izip_longest(fillvalue=fillvalue, *args)
def mosaic(w, imgs):
'''Make a grid from images.
w -- number of grid columns
imgs -- images (must have same size and format)
'''
imgs = iter(imgs)
img0 = imgs.next()
pad = np.zeros_like(img0)
imgs = it.chain([img0], imgs)
rows = grouper(w, imgs, pad)
return np.vstack(map(np.hstack, rows))
def getsize(img):
h, w = img.shape[:2]
return w, h
def mdot(*args):
return reduce(np.dot, args)
import numpy as np
import cv2
import os
from contextlib import contextmanager
import itertools as it
image_extensions = ['.bmp', '.jpg', '.jpeg', '.png', '.tif', '.tiff', '.pbm', '.pgm', '.ppm']
class Bunch(object):
def __init__(self, **kw):
self.__dict__.update(kw)
def __str__(self):
return str(self.__dict__)
def splitfn(fn):
path, fn = os.path.split(fn)
name, ext = os.path.splitext(fn)
return path, name, ext
def anorm2(a):
return (a*a).sum(-1)
def anorm(a):
return np.sqrt( anorm2(a) )
def homotrans(H, x, y):
xs = H[0, 0]*x + H[0, 1]*y + H[0, 2]
ys = H[1, 0]*x + H[1, 1]*y + H[1, 2]
s = H[2, 0]*x + H[2, 1]*y + H[2, 2]
return xs/s, ys/s
def to_rect(a):
a = np.ravel(a)
if len(a) == 2:
a = (0, 0, a[0], a[1])
return np.array(a, np.float64).reshape(2, 2)
def rect2rect_mtx(src, dst):
src, dst = to_rect(src), to_rect(dst)
cx, cy = (dst[1] - dst[0]) / (src[1] - src[0])
tx, ty = dst[0] - src[0] * (cx, cy)
M = np.float64([[ cx, 0, tx],
[ 0, cy, ty],
[ 0, 0, 1]])
return M
def lookat(eye, target, up = (0, 0, 1)):
fwd = np.asarray(target, np.float64) - eye
fwd /= anorm(fwd)
right = np.cross(fwd, up)
right /= anorm(right)
down = np.cross(fwd, right)
R = np.float64([right, down, fwd])
tvec = -np.dot(R, eye)
return R, tvec
def mtx2rvec(R):
w, u, vt = cv2.SVDecomp(R - np.eye(3))
p = vt[0] + u[:,0]*w[0] # same as np.dot(R, vt[0])
c = np.dot(vt[0], p)
s = np.dot(vt[1], p)
axis = np.cross(vt[0], vt[1])
return axis * np.arctan2(s, c)
def draw_str(dst, (x, y), s):
cv2.putText(dst, s, (x+1, y+1), cv2.FONT_HERSHEY_PLAIN, 1.0, (0, 0, 0), thickness = 2, lineType=cv2.CV_AA)
cv2.putText(dst, s, (x, y), cv2.FONT_HERSHEY_PLAIN, 1.0, (255, 255, 255), lineType=cv2.CV_AA)
class Sketcher:
def __init__(self, windowname, dests, colors_func):
self.prev_pt = None
self.windowname = windowname
self.dests = dests
self.colors_func = colors_func
self.dirty = False
self.show()
cv2.setMouseCallback(self.windowname, self.on_mouse)
def show(self):
cv2.imshow(self.windowname, self.dests[0])
def on_mouse(self, event, x, y, flags, param):
pt = (x, y)
if event == cv2.EVENT_LBUTTONDOWN:
self.prev_pt = pt
if self.prev_pt and flags & cv2.EVENT_FLAG_LBUTTON:
for dst, color in zip(self.dests, self.colors_func()):
cv2.line(dst, self.prev_pt, pt, color, 5)
self.dirty = True
self.prev_pt = pt
self.show()
else:
self.prev_pt = None
# palette data from matplotlib/_cm.py
_jet_data = {'red': ((0., 0, 0), (0.35, 0, 0), (0.66, 1, 1), (0.89,1, 1),
(1, 0.5, 0.5)),
'green': ((0., 0, 0), (0.125,0, 0), (0.375,1, 1), (0.64,1, 1),
(0.91,0,0), (1, 0, 0)),
'blue': ((0., 0.5, 0.5), (0.11, 1, 1), (0.34, 1, 1), (0.65,0, 0),
(1, 0, 0))}
cmap_data = { 'jet' : _jet_data }
def make_cmap(name, n=256):
data = cmap_data[name]
xs = np.linspace(0.0, 1.0, n)
channels = []
eps = 1e-6
for ch_name in ['blue', 'green', 'red']:
ch_data = data[ch_name]
xp, yp = [], []
for x, y1, y2 in ch_data:
xp += [x, x+eps]
yp += [y1, y2]
ch = np.interp(xs, xp, yp)
channels.append(ch)
return np.uint8(np.array(channels).T*255)
def nothing(*arg, **kw):
pass
def clock():
return cv2.getTickCount() / cv2.getTickFrequency()
@contextmanager
def Timer(msg):
print msg, '...',
start = clock()
try:
yield
finally:
print "%.2f ms" % ((clock()-start)*1000)
class StatValue:
def __init__(self, smooth_coef = 0.5):
self.value = None
self.smooth_coef = smooth_coef
def update(self, v):
if self.value is None:
self.value = v
else:
c = self.smooth_coef
self.value = c * self.value + (1.0-c) * v
class RectSelector:
def __init__(self, win, callback):
self.win = win
self.callback = callback
cv2.setMouseCallback(win, self.onmouse)
self.drag_start = None
self.drag_rect = None
def onmouse(self, event, x, y, flags, param):
x, y = np.int16([x, y]) # BUG
if event == cv2.EVENT_LBUTTONDOWN:
self.drag_start = (x, y)
if self.drag_start:
if flags & cv2.EVENT_FLAG_LBUTTON:
xo, yo = self.drag_start
x0, y0 = np.minimum([xo, yo], [x, y])
x1, y1 = np.maximum([xo, yo], [x, y])
self.drag_rect = None
if x1-x0 > 0 and y1-y0 > 0:
self.drag_rect = (x0, y0, x1, y1)
else:
rect = self.drag_rect
self.drag_start = None
self.drag_rect = None
if rect:
self.callback(rect)
def draw(self, vis):
if not self.drag_rect:
return False
x0, y0, x1, y1 = self.drag_rect
cv2.rectangle(vis, (x0, y0), (x1, y1), (0, 255, 0), 2)
return True
@property
def dragging(self):
return self.drag_rect is not None
def grouper(n, iterable, fillvalue=None):
'''grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx'''
args = [iter(iterable)] * n
return it.izip_longest(fillvalue=fillvalue, *args)
def mosaic(w, imgs):
'''Make a grid from images.
w -- number of grid columns
imgs -- images (must have same size and format)
'''
imgs = iter(imgs)
img0 = imgs.next()
pad = np.zeros_like(img0)
imgs = it.chain([img0], imgs)
rows = grouper(w, imgs, pad)
return np.vstack(map(np.hstack, rows))
def getsize(img):
h, w = img.shape[:2]
return w, h
def mdot(*args):
return reduce(np.dot, args)
def draw_keypoints(vis, keypoints, color = (0, 255, 255)):
for kp in keypoints:
x, y = kp.pt
cv2.circle(vis, (int(x), int(y)), 2, color)

@ -1,168 +1,88 @@
'''
Feature homography
==================
Example of using features2d framework for interactive video homography matching.
ORB features and FLANN matcher are used.
Inspired by http://www.youtube.com/watch?v=-ZNYoL8rzPY
Usage
-----
feature_homography.py [<video source>]
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 collections import namedtuple
from common import getsize
FLANN_INDEX_KDTREE = 1
FLANN_INDEX_LSH = 6
flann_params= dict(algorithm = FLANN_INDEX_LSH,
table_number = 6, # 12
key_size = 12, # 20
multi_probe_level = 1) #2
MIN_MATCH_COUNT = 10
ar_verts = np.float32([[0, 0, 0], [0, 1, 0], [1, 1, 0], [1, 0, 0],
[0, 0, 1], [0, 1, 1], [1, 1, 1], [1, 0, 1],
[0.5, 0.5, 2]])
ar_edges = [(0, 1), (1, 2), (2, 3), (3, 0),
(4, 5), (5, 6), (6, 7), (7, 4),
(0, 4), (1, 5), (2, 6), (3, 7),
(4, 8), (5, 8), (6, 8), (7, 8)]
def draw_keypoints(vis, keypoints, color = (0, 255, 255)):
for kp in keypoints:
x, y = kp.pt
cv2.circle(vis, (int(x), int(y)), 2, color)
class App:
def __init__(self, src):
self.cap = video.create_capture(src)
self.frame = None
self.paused = False
self.ref_frame = None
self.detector = cv2.ORB( nfeatures = 1000 )
self.matcher = cv2.FlannBasedMatcher(flann_params, {}) # bug : need to pass empty dict (#1329)
cv2.namedWindow('plane')
self.rect_sel = common.RectSelector('plane', self.on_rect)
def match_frames(self):
if len(self.frame_desc) < MIN_MATCH_COUNT or len(self.frame_desc) < MIN_MATCH_COUNT:
return
raw_matches = self.matcher.knnMatch(self.frame_desc, k = 2)
p0, p1 = [], []
for m in raw_matches:
if len(m) == 2 and m[0].distance < m[1].distance * 0.75:
m = m[0]
p0.append( self.ref_points[m.trainIdx].pt ) # queryIdx
p1.append( self.frame_points[m.queryIdx].pt )
p0, p1 = np.float32((p0, p1))
if len(p0) < MIN_MATCH_COUNT:
return
H, status = cv2.findHomography(p0, p1, cv2.RANSAC, 4.0)
status = status.ravel() != 0
if status.sum() < MIN_MATCH_COUNT:
return
p0, p1 = p0[status], p1[status]
return p0, p1, H
def on_frame(self, vis):
match = self.match_frames()
if match is None:
return
w, h = getsize(self.frame)
p0, p1, H = match
for (x0, y0), (x1, y1) in zip(np.int32(p0), np.int32(p1)):
cv2.line(vis, (x0+w, y0), (x1, y1), (0, 255, 0))
x0, y0, x1, y1 = self.ref_rect
corners0 = np.float32([[x0, y0], [x1, y0], [x1, y1], [x0, y1]])
img_corners = cv2.perspectiveTransform(corners0.reshape(1, -1, 2), H)
cv2.polylines(vis, [np.int32(img_corners)], True, (255, 255, 255), 2)
corners3d = np.hstack([corners0, np.zeros((4, 1), np.float32)])
fx = 0.9
K = np.float64([[fx*w, 0, 0.5*(w-1)],
[0, fx*w, 0.5*(h-1)],
[0.0,0.0, 1.0]])
dist_coef = np.zeros(4)
ret, rvec, tvec = cv2.solvePnP(corners3d, img_corners, K, dist_coef)
verts = ar_verts * [(x1-x0), (y1-y0), -(x1-x0)*0.3] + (x0, y0, 0)
verts = cv2.projectPoints(verts, rvec, tvec, K, dist_coef)[0].reshape(-1, 2)
for i, j in ar_edges:
(x0, y0), (x1, y1) = verts[i], verts[j]
cv2.line(vis, (int(x0), int(y0)), (int(x1), int(y1)), (255, 255, 0), 2)
def on_rect(self, rect):
x0, y0, x1, y1 = rect
self.ref_frame = self.frame.copy()
self.ref_rect = rect
points, descs = [], []
for kp, desc in zip(self.frame_points, self.frame_desc):
x, y = kp.pt
if x0 <= x <= x1 and y0 <= y <= y1:
points.append(kp)
descs.append(desc)
self.ref_points, self.ref_descs = points, np.uint8(descs)
self.matcher.clear()
self.matcher.add([self.ref_descs])
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 = np.fliplr(frame).copy()
self.frame_points, self.frame_desc = self.detector.detectAndCompute(self.frame, None)
if self.frame_desc is None: # detectAndCompute returns descs=None if not keypoints found
self.frame_desc = []
w, h = getsize(self.frame)
vis = np.zeros((h, w*2, 3), np.uint8)
vis[:h,:w] = self.frame
if self.ref_frame is not None:
vis[:h,w:] = self.ref_frame
x0, y0, x1, y1 = self.ref_rect
cv2.rectangle(vis, (x0+w, y0), (x1+w, y1), (0, 255, 0), 2)
draw_keypoints(vis[:,w:], self.ref_points)
draw_keypoints(vis, self.frame_points)
if playing and self.ref_frame is not None:
self.on_frame(vis)
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()
'''
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 = np.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()

@ -0,0 +1,103 @@
'''
Planar augmented reality
==================
This sample shows an example of augmented reality overlay over a planar object
tracked by PlaneTracker from plane_tracker.py. solvePnP funciton is used to
estimate the tracked object location in 3d space.
video: http://www.youtube.com/watch?v=pzVbhxx6aog
Usage
-----
plane_ar.py [<video source>]
Keys:
SPACE - pause video
c - clear targets
Select a textured planar object to track by drawing a box with a mouse.
Use 'focal' slider to adjust to camera focal length for proper video augmentation.
'''
import numpy as np
import cv2
import video
import common
from plane_tracker import PlaneTracker
ar_verts = np.float32([[0, 0, 0], [0, 1, 0], [1, 1, 0], [1, 0, 0],
[0, 0, 1], [0, 1, 1], [1, 1, 1], [1, 0, 1],
[0, 0.5, 2], [1, 0.5, 2]])
ar_edges = [(0, 1), (1, 2), (2, 3), (3, 0),
(4, 5), (5, 6), (6, 7), (7, 4),
(0, 4), (1, 5), (2, 6), (3, 7),
(4, 8), (5, 8), (6, 9), (7, 9), (8, 9)]
class App:
def __init__(self, src):
self.cap = video.create_capture(src)
self.frame = None
self.paused = False
self.tracker = PlaneTracker()
cv2.namedWindow('plane')
cv2.createTrackbar('focal', 'plane', 25, 50, common.nothing)
self.rect_sel = common.RectSelector('plane', self.on_rect)
def on_rect(self, rect):
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()
vis = self.frame.copy()
if playing:
tracked = self.tracker.track(self.frame)
for tr in tracked:
cv2.polylines(vis, [np.int32(tr.quad)], True, (255, 255, 255), 2)
for (x, y) in np.int32(tr.p1):
cv2.circle(vis, (x, y), 2, (255, 255, 255))
self.draw_overlay(vis, tr)
self.rect_sel.draw(vis)
cv2.imshow('plane', vis)
ch = cv2.waitKey(1)
if ch == ord(' '):
self.paused = not self.paused
if ch == ord('c'):
self.tracker.clear()
if ch == 27:
break
def draw_overlay(self, vis, tracked):
x0, y0, x1, y1 = tracked.target.rect
quad_3d = np.float32([[x0, y0, 0], [x1, y0, 0], [x1, y1, 0], [x0, y1, 0]])
fx = 0.5 + cv2.getTrackbarPos('focal', 'plane') / 50.0
h, w = vis.shape[:2]
K = np.float64([[fx*w, 0, 0.5*(w-1)],
[0, fx*w, 0.5*(h-1)],
[0.0,0.0, 1.0]])
dist_coef = np.zeros(4)
ret, rvec, tvec = cv2.solvePnP(quad_3d, tracked.quad, K, dist_coef)
verts = ar_verts * [(x1-x0), (y1-y0), -(x1-x0)*0.3] + (x0, y0, 0)
verts = cv2.projectPoints(verts, rvec, tvec, K, dist_coef)[0].reshape(-1, 2)
for i, j in ar_edges:
(x0, y0), (x1, y1) = verts[i], verts[j]
cv2.line(vis, (int(x0), int(y0)), (int(x1), int(y1)), (255, 255, 0), 2)
if __name__ == '__main__':
print __doc__
import sys
try: video_src = sys.argv[1]
except: video_src = 0
App(video_src).run()

@ -0,0 +1,171 @@
'''
Multitarget planar tracking
==================
Example of using features2d framework for interactive video homography matching.
ORB features and FLANN matcher are used. This sample provides PlaneTracker class
and an example of its usage.
video: http://www.youtube.com/watch?v=pzVbhxx6aog
Usage
-----
plane_tracker.py [<video source>]
Keys:
SPACE - pause video
c - clear targets
Select a textured planar object to track by drawing a box with a mouse.
'''
import numpy as np
import cv2
from collections import namedtuple
import video
import common
FLANN_INDEX_KDTREE = 1
FLANN_INDEX_LSH = 6
flann_params= dict(algorithm = FLANN_INDEX_LSH,
table_number = 6, # 12
key_size = 12, # 20
multi_probe_level = 1) #2
MIN_MATCH_COUNT = 10
'''
image - image to track
rect - tracked rectangle (x1, y1, x2, y2)
keypoints - keypoints detected inside rect
descrs - their descriptors
data - some user-provided data
'''
PlanarTarget = namedtuple('PlaneTarget', 'image, rect, keypoints, descrs, data')
'''
target - reference to PlanarTarget
p0 - matched points coords in target image
p1 - matched points coords in input frame
H - homography matrix from p0 to p1
quad - target bounary quad in input frame
'''
TrackedTarget = namedtuple('TrackedTarget', 'target, p0, p1, H, quad')
class PlaneTracker:
def __init__(self):
self.detector = cv2.ORB( nfeatures = 1000 )
self.matcher = cv2.FlannBasedMatcher(flann_params, {}) # bug : need to pass empty dict (#1329)
self.targets = []
def add_target(self, image, rect, data=None):
'''Add a new tracking target.'''
x0, y0, x1, y1 = rect
raw_points, raw_descrs = self.detect_features(image)
points, descs = [], []
for kp, desc in zip(raw_points, raw_descrs):
x, y = kp.pt
if x0 <= x <= x1 and y0 <= y <= y1:
points.append(kp)
descs.append(desc)
descs = np.uint8(descs)
self.matcher.add([descs])
target = PlanarTarget(image = image, rect=rect, keypoints = points, descrs=descs, data=None)
self.targets.append(target)
def clear(self):
'''Remove all targets'''
self.targets = []
self.matcher.clear()
def track(self, frame):
'''Returns a list of detected TrackedTarget objects'''
self.frame_points, self.frame_descrs = self.detect_features(frame)
if len(self.frame_points) < MIN_MATCH_COUNT:
return []
matches = self.matcher.knnMatch(self.frame_descrs, k = 2)
matches = [m[0] for m in matches if len(m) == 2 and m[0].distance < m[1].distance * 0.75]
if len(matches) < MIN_MATCH_COUNT:
return []
matches_by_id = [[] for _ in xrange(len(self.targets))]
for m in matches:
matches_by_id[m.imgIdx].append(m)
tracked = []
for imgIdx, matches in enumerate(matches_by_id):
if len(matches) < MIN_MATCH_COUNT:
continue
target = self.targets[imgIdx]
p0 = [target.keypoints[m.trainIdx].pt for m in matches]
p1 = [self.frame_points[m.queryIdx].pt for m in matches]
p0, p1 = np.float32((p0, p1))
H, status = cv2.findHomography(p0, p1, cv2.RANSAC, 3.0)
status = status.ravel() != 0
if status.sum() < MIN_MATCH_COUNT:
continue
p0, p1 = p0[status], p1[status]
x0, y0, x1, y1 = target.rect
quad = np.float32([[x0, y0], [x1, y0], [x1, y1], [x0, y1]])
quad = cv2.perspectiveTransform(quad.reshape(1, -1, 2), H).reshape(-1, 2)
track = TrackedTarget(target=target, p0=p0, p1=p1, H=H, quad=quad)
tracked.append(track)
tracked.sort(key = lambda t: len(t.p0), reverse=True)
return tracked
def detect_features(self, frame):
'''detect_features(self, frame) -> keypoints, descrs'''
keypoints, descrs = self.detector.detectAndCompute(frame, None)
if descrs is None: # detectAndCompute returns descs=None if not keypoints found
descrs = []
return keypoints, descrs
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.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()
vis = self.frame.copy()
if playing:
tracked = self.tracker.track(self.frame)
for tr in tracked:
cv2.polylines(vis, [np.int32(tr.quad)], True, (255, 255, 255), 2)
for (x, y) in np.int32(tr.p1):
cv2.circle(vis, (x, y), 2, (255, 255, 255))
self.rect_sel.draw(vis)
cv2.imshow('plane', vis)
ch = cv2.waitKey(1)
if ch == ord(' '):
self.paused = not self.paused
if ch == ord('c'):
self.tracker.clear()
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()
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