def before(self):
"""
prepare for the loop
"""
self.onWork = 0
self.absx,self.absy = 0, 0
self.lastdx, self.lastdy = 0, 0
self.tr = 0
self.preview_size = 500
self.preview = trainscanner.fit_to_square(self.frame, self.preview_size)
self.preview_ratio = float(self.preview.shape[0]) / self.frame.shape[0]
def __init__(self, parent=None, filename="", size=0):
super(AsyncImageLoader, self).__init__(parent)
self.isRunning = True
#capture the first frame ASAP to avoid "no frame" errors.
self.size = size
self.cap = cv2.VideoCapture(filename)
ret, frame = self.cap.read()
if self.size:
frame = trainscanner.fit_to_square(frame, self.size)
self.snapshots = [frame]
def task(self):
if not self.isRunning:
self.isRunning = True
while self.isRunning:
ret, frame = self.cap.read()
if not ret:
break
if self.count % 10 == 0: #load every 10 frames; it might be too many.
if self.size:
frame = trainscanner.fit_to_square(frame, self.size)
self.snapshots.append(frame)
#print(len(self.snapshots))
#these are for the preview, so we can shrink it.
self.frameIncreased.emit(len(self.snapshots))
self.count += 1
def task(self):
if not self.isRunning:
self.isRunning = True
while self.isRunning:
ret, frame = self.cap.read()
if not ret:
break
if self.size:
frame = trainscanner.fit_to_square(frame, self.size)
self.snapshots.append(frame)
self.frameIncreased.emit(self.snapshots)
for i in range(9):
ret = self.cap.grab()
if not ret:
break
def onestep(self):
ret = True
##### Pick up every x frame
for i in range(self.every-1):
ret = self.cap.grab()
self.nframes += 1
if not ret:
return None
ret, nextframe = self.cap.read()
self.nframes += 1
##### return None if the frame is empty
if not ret:
return None
##### compare with the previous raw frame
diff = cv2.absdiff(nextframe,self.rawframe)
diff = np.sum(diff) / np.product(diff.shape)
if diff < self.identity:
sys.stderr.write("skip identical frame #{0}\n".format(diff))
#They are identical frames
#This happens when the frame rate difference is compensated.
return True
##### preserve the raw frame for next comparison.
self.rawframe = nextframe.copy()
##### Warping the frame
#######(1) rotation
if self.angle:
nextframe = cv2.warpAffine(nextframe, self.R, (self.rotated_w,self.rotated_h))
#w and h are sizes after rotation
#######(2) skew deformation
if self.M is not None:
#this does not change the aspect ratio
nextframe = cv2.warpPerspective(nextframe,self.M,(self.rotated_w,self.rotated_h))
#######(3) top-bottom crop
nextframe = nextframe[self.crop[0]*self.rotated_h/1000:self.crop[1]*self.rotated_h/1000, :, :]
##### Make the preview image
nextpreview = trainscanner.fit_to_square(nextframe,self.preview_size)
##### motion detection.
#if margin is set, motion detection area becomes very narrow
#assuming that the train is running at constant speed.
#This mode is activated after the 10th frames.
if self.margin > 0 and self.onWork > 10:
#do not apply margin for the first 10 frames
#because the velocity uncertainty.
dx,dy = trainscanner.motion(self.frame, nextframe, focus=self.focus, margin=self.margin, delta=(self.lastdx,self.lastdy) )
else:
dx,dy = trainscanner.motion(self.frame, nextframe, focus=self.focus)
sys.stderr.write("{0} {1} {2} #{3}\n".format(self.nframes,dx,dy,np.amax(diff)))
if self.zero:
if abs(dx) < abs(dy):
dx = 0
else:
dy = 0
diff_img = diffImage(nextpreview,self.preview,int(dx*self.preview_ratio),int(dy*self.preview_ratio),focus=self.focus)
if (abs(dx) > self.antishake or abs(dy) > self.antishake):
self.onWork += 1
self.tr = 0
else:
if self.onWork:
if self.tr <= self.trailing:
self.tr += 1
dx = self.lastdx
dy = self.lastdy
sys.stderr.write(">>({2}) {0} {1} #{3}\n".format(dx,dy,self.tr,np.amax(diff)))
else:
#end of work
return None
self.absx += dx
self.absy += dy
if self.onWork:
self.lastdx, self.lastdy = dx,dy
self.canvas = canvas_size(self.canvas, nextframe, self.absx, self.absy)
#sys.stderr.write("canvas size{0} {1}\n".format(self.canvas[0],self.canvas[1]))
self.LOG.write("{0} {1} {2} {3} {4}\n".format(self.nframes,self.absx,self.absy,dx,dy))
self.LOG.flush()
#This flushes the buffer, that causes immediate processing in the next command connected by a pipe "|"
self.frame = nextframe
self.preview = nextpreview
return diff_img
