def lucas_kanade(self):
vid = cv.CaptureFromFile(self.path)
first_frame = cv_compat.get_gray_frame(vid)
velx = cv.CreateImage(cv.GetSize(first_frame), cv.IPL_DEPTH_32F, 1)
vely = cv.CreateImage(cv.GetSize(first_frame), cv.IPL_DEPTH_32F, 1)
for prev_frame, curr_frame, curr_frame_color in self._iter_frames(vid):
cv.CalcOpticalFlowLK(prev_frame, curr_frame, (15, 15), velx, vely)
flow = np.dstack(
(np.asarray(cv.GetMat(velx)), np.asarray(cv.GetMat(vely))))
yield Flow(flow, curr_frame, prev_frame, curr_frame_color)
cv.Line(desImageHS, (i, j), (i + dx, j + dy), (0, 0, 255), 1, cv.CV_AA,
0)
f.writelines(
[str(i), ' ',
str(j), ' ',
str(i + dx), ' ',
str(j + dy), '\n'])
# count+=1
# print count
f.close()
cv.SetZero(velx)
cv.SetZero(vely)
#包含了实现CalcOpticalFlowLK的方法
cv.CalcOpticalFlowLK(inputImageFirst, inputImageSecond, (15, 15), velx, vely)
for i in range(0, cols, FLOWSKIP):
for j in range(0, rows, FLOWSKIP):
dx = int(cv.GetReal2D(velx, j, i))
dy = int(cv.GetReal2D(vely, j, i))
cv.Line(desImageLK, (i, j), (i + dx, j + dy), (0, 0, 255), 1, cv.CV_AA,
0)
cv.SaveImage("resultHS.png", desImageHS)
cv.SaveImage("resultLK.png", desImageLK)
cv.NamedWindow("Optical flow HS")
cv.ShowImage("Optical flow HS", desImageHS)
cv.NamedWindow("Optical flow LK")
def calcOpticalFlow(self, curImageGray, method="BlockMatching"):
if curImageGray.channels != 1:
raise Exception("Only able to process gray-scale images")
if self.lastImageGray == None:
lastImageGray = curImageGray
else:
lastImageGray = self.lastImageGray
# Create storage for the optical flow
storageWidth = self.calcOpticalFlowWidth(lastImageGray.width)
storageHeight = self.calcOpticalFlowHeight(lastImageGray.height)
if method == "BlockMatching":
opticalFlowArrayX = np.ndarray(shape=(storageHeight, storageWidth),
dtype=np.float32)
opticalFlowArrayY = np.ndarray(shape=(storageHeight, storageWidth),
dtype=np.float32)
cv.CalcOpticalFlowBM(
lastImageGray, curImageGray,
(self.opticalFlowBlockWidth, self.opticalFlowBlockHeight),
(self.opticalFlowBlockWidth, self.opticalFlowBlockHeight),
(self.opticalFlowRangeWidth, self.opticalFlowRangeHeight), 0,
cv.fromarray(opticalFlowArrayX),
cv.fromarray(opticalFlowArrayY))
elif method == "LucasKanade":
largeOpticalFlowArrayX = np.ndarray(shape=(lastImageGray.height,
lastImageGray.width),
dtype=np.float32)
largeOpticalFlowArrayY = np.ndarray(shape=(lastImageGray.height,
lastImageGray.width),
dtype=np.float32)
cv.CalcOpticalFlowLK(
lastImageGray,
curImageGray,
(
15, 15
), #( self.opticalFlowBlockWidth, self.opticalFlowBlockHeight ),
cv.fromarray(largeOpticalFlowArrayX),
cv.fromarray(largeOpticalFlowArrayY))
indexGrid = np.mgrid[0:storageHeight, 0:storageWidth]
indexGrid[0] = indexGrid[
0] * self.opticalFlowBlockHeight + self.opticalFlowBlockHeight / 2
indexGrid[1] = indexGrid[
1] * self.opticalFlowRangeWidth + self.opticalFlowRangeWidth / 2
opticalFlowArrayX = largeOpticalFlowArrayX[indexGrid[0],
indexGrid[1]]
opticalFlowArrayY = largeOpticalFlowArrayY[indexGrid[0],
indexGrid[1]]
elif method == "HornSchunck":
largeOpticalFlowArrayX = np.ndarray(shape=(lastImageGray.height,
lastImageGray.width),
dtype=np.float32)
largeOpticalFlowArrayY = np.ndarray(shape=(lastImageGray.height,
lastImageGray.width),
dtype=np.float32)
cv.CalcOpticalFlowHS(
lastImageGray, curImageGray, 0,
cv.fromarray(largeOpticalFlowArrayX),
cv.fromarray(largeOpticalFlowArrayY), 1.0,
(cv.CV_TERMCRIT_ITER | cv.CV_TERMCRIT_EPS, 10, 0.01))
indexGrid = np.mgrid[0:storageHeight, 0:storageWidth]
indexGrid[0] = indexGrid[
0] * self.opticalFlowBlockHeight + self.opticalFlowBlockHeight / 2
indexGrid[1] = indexGrid[
1] * self.opticalFlowRangeWidth + self.opticalFlowRangeWidth / 2
opticalFlowArrayX = largeOpticalFlowArrayX[indexGrid[0],
indexGrid[1]]
opticalFlowArrayY = largeOpticalFlowArrayY[indexGrid[0],
indexGrid[1]]
else:
raise Exception("Unhandled method")
# Save the current image
self.lastImageGray = curImageGray
return (opticalFlowArrayX, opticalFlowArrayY)