def get_subwindow(im, pos, sz, cos_window):
"""
使用 replication padding 从图像中获得子窗口。子窗口以 [y, x] 为坐标中心，大小为 [height, width].
如果子窗口超过图像边界，则复制图像的边界像素值。获得的子窗口将使用余弦窗口标准化到 [-0.5, 0.5]
:param im: 输入图像
:param pos: 子窗口中心点坐标 [y, x]
:param sz: 子窗口大小 [height, width]
:param cos_window: 余弦子窗口矩阵
:return: 返回经过余弦子窗口截取的图像矩形框部分
"""
# 如果不是高、宽组成的数组，而是一个一维数值，则转化为一个数组
# 目标是子窗矩形化
if pylab.isscalar(sz): # square sub-window
sz = [sz, sz]
# 以 pos 为中心，以 sz 为窗口大小建立子窗
ys = pylab.floor(pos[0]) + pylab.arange(sz[0], dtype=int) - pylab.floor(
sz[0] / 2)
xs = pylab.floor(pos[1]) + pylab.arange(sz[1], dtype=int) - pylab.floor(
sz[1] / 2)
ys = ys.astype(int)
xs = xs.astype(int)
# 如果子窗超过坐标，则设置为边界值
ys[ys < 0] = 0
ys[ys >= im.shape[0]] = im.shape[0] - 1
xs[xs < 0] = 0
xs[xs >= im.shape[1]] = im.shape[1] - 1
# 提取子窗剪切的图像块
out = im[pylab.ix_(ys, xs)]
# 将图像像素值从 [0, 1] 平移到 [-0.5, 0.5]
out = out.astype(pylab.float64) - 0.5
# 余弦窗口化，论文公式 (18)
return pylab.multiply(cos_window, out)
def Global_Stiffness(self):
'''
Generates Global Stiffness Matrix for the plane structure
'''
elem = self.element;
B = py.zeros((6,6))
for i in range (0,py.size(elem,0)):
#for each element find the stifness matrix
K = py.zeros((self.n_nodes*2,self.n_nodes*2))
el = elem[i]
#nodes formatted for input
[node1, node2, node3] = el;
node1x = 2*(node1-1);node2x = 2*(node2-1);node3x = 2*(node3-1);
node1y = 2*(node1-1)+1;node2y = 2*(node2-1)+1;node3y = 2*(node3-1)+1;
#Area, Strain Matrix and E Matrix multiplied to get element stiffness
[J,B] = self.B(el)
local_k =0.5*abs(J)*py.dot(py.transpose(B),py.dot(self.E_matrix,B))
if self.debug:
print 'K for elem', el, '\n', local_k
#Element K-Matrix converted into Global K-Matrix format
K[py.ix_([node1x,node1y,node2x,node2y,node3x,node3y],[node1x,node1y,node2x,node2y,node3x,node3y])] = K[py.ix_([node1x,node1y,node2x,node2y,node3x,node3y],[node1x,node1y,node2x,node2y,node3x,node3y])]+local_k
#Adding contibution into Global Stiffness
self.k_global = self.k_global + K
if self.debug:
print 'Global Stiffness','\n', self.k_global
def get_subwindow(self, im, pos, sz):
"""
Obtain sub-window from image, with replication-padding.
Returns sub-window of image IM centered at POS ([y, x] coordinates),
with size SZ ([height, width]). If any pixels are outside of the image,
they will replicate the values at the borders.
The subwindow is also normalized to range -0.5 .. 0.5, and the given
cosine window COS_WINDOW is applied
(though this part could be omitted to make the function more general).
"""
if pylab.isscalar(sz): # square sub-window
sz = [sz, sz]
ys = pylab.floor(pos[0]) \
+ pylab.arange(sz[0], dtype=int) - pylab.floor(sz[0]/2)
xs = pylab.floor(pos[1]) \
+ pylab.arange(sz[1], dtype=int) - pylab.floor(sz[1]/2)
ys = ys.astype(int)
xs = xs.astype(int)
# check for out-of-bounds coordinates,
# and set them to the values at the borders
ys[ys < 0] = 0
ys[ys >= im.shape[0]] = im.shape[0] - 1
xs[xs < 0] = 0
xs[xs >= im.shape[1]] = im.shape[1] - 1
#zs = range(im.shape[2])
# extract image
#out = im[pylab.ix_(ys, xs, zs)]
out = im[pylab.ix_(ys, xs)]
out = cv2.resize(out, dsize = (int(self.window_sz[1]), int(self.window_sz[0])), fx=0, fy=0)
#cos_window = pylab.outer(pylab.hanning(sz[0]), pylab.hanning(sz[1]))
if debug:
print("Out max/min value==", out.max(), "/", out.min())
pylab.figure()
pylab.imshow(out, cmap=pylab.cm.gray)
pylab.title("cropped subwindow")
#pre-process window --
# normalize to range -0.5 .. 0.5
# pixels are already in range 0 to 1
out = out.astype(pylab.float64) - 0.5
# apply cosine window
#out = pylab.multiply(cos_window, out)
out = pylab.multiply(self.cos_window, out)
return out
def get_subwindow(im, pos, sz, cos_window):
"""
Obtain sub-window from image, with replication-padding.
Returns sub-window of image IM centered at POS ([y, x] coordinates),
with size SZ ([height, width]). If any pixels are outside of the image,
they will replicate the values at the borders.
The subwindow is also normalized to range -0.5 .. 0.5, and the given
cosine window COS_WINDOW is applied
(though this part could be omitted to make the function more general).
"""
if pylab.isscalar(sz): # square sub-window
sz = [sz, sz]
ys = pylab.floor(pos[0]) \
+ pylab.arange(sz[0], dtype=int) - pylab.floor(sz[0]/2)
xs = pylab.floor(pos[1]) \
+ pylab.arange(sz[1], dtype=int) - pylab.floor(sz[1]/2)
ys = ys.astype(int)
xs = xs.astype(int)
# check for out-of-bounds coordinates,
# and set them to the values at the borders
ys[ys < 0] = 0
ys[ys >= im.shape[0]] = im.shape[0] - 1
xs[xs < 0] = 0
xs[xs >= im.shape[1]] = im.shape[1] - 1
#zs = range(im.shape[2])
# extract image
#out = im[pylab.ix_(ys, xs, zs)]
out = im[pylab.ix_(ys, xs)]
if debug:
print("Out max/min value==", out.max(), "/", out.min())
pylab.figure()
pylab.imshow(out, cmap=pylab.cm.gray)
pylab.title("cropped subwindow")
#pre-process window --
# normalize to range -0.5 .. 0.5
# pixels are already in range 0 to 1
out = out.astype(pylab.float64) / 255 - 0.5
# apply cosine window
out = pylab.multiply(cos_window, out)
return out
def get_subwindow(image, box):
xs = pylab.floor(box[0]) \
+ pylab.arange(box[4], dtype=int) - pylab.floor(box[4] / 2)
ys = pylab.floor(box[1]) \
+ pylab.arange(box[5], dtype=int) - pylab.floor(box[5] / 2)
xs = xs.astype(int)
ys = ys.astype(int)
xs[xs < 0] = 0
xs[xs >= image.shape[1]] = image.shape[1] - 1
ys[ys < 0] = 0
ys[ys >= image.shape[0]] = image.shape[0] - 1
return image[pylab.ix_(ys, xs, range(image.shape[2]))]
def get_imageROI(self, im, rect):
ys = pylab.floor(rect[1]) + pylab.arange(rect[3], dtype=int)
xs = pylab.floor(rect[0]) + pylab.arange(rect[2], dtype=int)
ys = ys.astype(int)
xs = xs.astype(int)
# check for out-of-bounds coordinates,
# and set them to the values at the borders
ys[ys < 0] = 0
ys[ys >= im.shape[0]] = im.shape[0] - 1
xs[xs < 0] = 0
xs[xs >= im.shape[1]] = im.shape[1] - 1
roi = im[pylab.ix_(ys, xs)]
return roi
def StiffnessAndStrain(self):
'''
Function to obtain stiffness matrix and strains in each element
'''
for el in range(self.n_element): #enumerate through all the elements
K = py.zeros((self.n_nodes*2,self.n_nodes*2))#Full stiffness matrix for one element
if self._debug:
print 'bar element:', el+1
startNode = self._connectivity[el,0]-1 #start and end node of the element
endNode = self._connectivity[el,1]-1
startXY = self._xy[startNode] #start and end coordinates of the element
endXY = self._xy[endNode]
L = py.norm(endXY - startXY) # Length of the element
self.L[el]= L
#new start and end coordinates of the element
newstartXY=self._xy[startNode]+self._displacement[startNode]
newendXY=self._xy[endNode]+self._displacement[endNode]
newL=py.norm(newendXY - newstartXY) # Deformed Length of the element
self.strain_global.append((newL-L)/L); # Axial Strain in element
T = py.zeros((4,2))
T = self.Transform2D(startXY,endXY) #get the Transformation matrix for the element
if self._debug:
print startNode, endNode, startXY, endXY
print 'T'
print T
L_inv = 1.0/L
k0=py.array([[L_inv, -L_inv],[-L_inv, L_inv]])#Stiffness matrix in 1D
k_element = py.dot(T,py.dot(k0,py.transpose(T)) )#Stiffness matrix in 2D
#Convert from 2x2 local K matrix to a full stiffness matrix but for single element
K[py.ix_([2*startNode,2*startNode+1,2*endNode,2*endNode+1],[2*startNode,2*startNode+1,2*endNode,2*endNode+1])] = K[py.ix_([2*startNode,2*startNode+1,2*endNode,2*endNode+1],[2*startNode,2*startNode+1,2*endNode,2*endNode+1])]+k_element
if self._debug:
print 'element stiffness', 'L_inv', L_inv
print k_element
print 'K'
print K
self.k_global = self.k_global + K # Assemble all the stiffness into one Global Stiffness
return self.k_global,self.strain_global
