def down_sampling(x,
kernal,
phase,
drop,
image_z=None,
height=None,
width=None,
scope=None):
with tf.name_scope(scope):
W = weight_xavier_init(shape=kernal,
n_inputs=kernal[0] * kernal[1] * kernal[2] *
kernal[3],
n_outputs=kernal[-1],
activefunction='relu',
variable_name=scope + 'W')
B = bias_variable([kernal[-1]], variable_name=scope + 'B')
conv = conv3d(x, W, 2) + B
conv = normalizationlayer(conv,
is_train=phase,
height=height,
width=width,
image_z=image_z,
norm_type='group',
G=20,
scope=scope)
conv = tf.nn.dropout(tf.nn.relu(conv), drop)
return conv
def attngatingblock(x, g, inputfilters, outfilters, scale_factor, phase, image_z=None, height=None, width=None,
scope=None):
"""
take g which is the spatially smaller signal, do a conv to get the same number of feature channels as x (bigger spatially)
do a conv on x to also get same feature channels (theta_x)
then, upsample g to be same size as x add x and g (concat_xg) relu, 1x1x1 conv, then sigmoid then upsample the final -
this gives us attn coefficients
:param x:
:param g:
:param inputfilters:
:param outfilters:
:param scale_factor:2
:param scope:
:return:
"""
with tf.name_scope(scope):
kernalx = (1, 1, 1, inputfilters, outfilters)
Wx = weight_xavier_init(shape=kernalx, n_inputs=kernalx[0] * kernalx[1] * kernalx[2] * kernalx[3],
n_outputs=kernalx[-1], activefunction='relu', variable_name=scope + 'conv_Wx')
Bx = bias_variable([kernalx[-1]], variable_name=scope + 'conv_Bx')
theta_x = conv3d(x, Wx, scale_factor) + Bx
kernalg = (1, 1, 1, inputfilters, outfilters)
Wg = weight_xavier_init(shape=kernalg, n_inputs=kernalg[0] * kernalg[1] * kernalg[2] * kernalg[3],
n_outputs=kernalg[-1], activefunction='relu', variable_name=scope + 'conv_Wg')
Bg = bias_variable([kernalg[-1]], variable_name=scope + 'conv_Bg')
phi_g = conv3d(g, Wg) + Bg
add_xg = resnet_Add(theta_x, phi_g)
act_xg = tf.nn.relu(add_xg)
kernalpsi = (1, 1, 1, outfilters, 1)
Wpsi = weight_xavier_init(shape=kernalpsi, n_inputs=kernalpsi[0] * kernalpsi[1] * kernalpsi[2] * kernalpsi[3],
n_outputs=kernalpsi[-1], activefunction='relu', variable_name=scope + 'conv_Wpsi')
Bpsi = bias_variable([kernalpsi[-1]], variable_name=scope + 'conv_Bpsi')
psi = conv3d(act_xg, Wpsi) + Bpsi
sigmoid_psi = tf.nn.sigmoid(psi)
upsample_psi = upsample3d(sigmoid_psi, scale_factor=scale_factor, scope=scope + "resampler")
# Attention: upsample_psi * x
# upsample_psi = layers.Lambda(lambda x, repnum: K.repeat_elements(x, repnum, axis=4),
# arguments={'repnum': outfilters})(upsample_psi)
gat_x = tf.multiply(upsample_psi, x)
kernal_gat_x = (1, 1, 1, outfilters, outfilters)
Wgatx = weight_xavier_init(shape=kernal_gat_x,
n_inputs=kernal_gat_x[0] * kernal_gat_x[1] * kernal_gat_x[2] * kernal_gat_x[3],
n_outputs=kernal_gat_x[-1], activefunction='relu',
variable_name=scope + 'conv_Wgatx')
Bgatx = bias_variable([kernalpsi[-1]], variable_name=scope + 'conv_Bgatx')
gat_x_out = conv3d(gat_x, Wgatx) + Bgatx
gat_x_out = normalizationlayer(gat_x_out, is_train=phase, height=height, width=width, image_z=image_z,
norm_type='group', scope=scope)
return gat_x_out
def conv_bn_relu_drop(x, kernal, phase, drop, image_z=None, height=None, width=None, scope=None):
"""
:param x:
:param kernal:
:param phase:
:param drop:
:param image_z:
:param height:
:param width:
:param scope:
:return:
"""
with tf.name_scope(scope):
W = weight_xavier_init(shape=kernal, n_inputs=kernal[0] * kernal[1] * kernal[2] * kernal[3],
n_outputs=kernal[-1], activefunction='relu', variable_name=scope + 'conv_W')
B = bias_variable([kernal[-1]], variable_name=scope + 'conv_B')
conv = conv3d(x, W) + B
conv = normalizationlayer(conv, is_train=phase, height=height, width=width, image_z=image_z, norm_type='group',
scope=scope)
conv = tf.nn.dropout(tf.nn.relu(conv), drop)
return conv
def gatingsignal3d(x, kernal, phase, image_z=None, height=None, width=None, scope=None):
"""this is simply 1x1x1 convolution, bn, activation,Gating Signal(Query)
:param x:
:param kernal:(1,1,1,inputfilters,outputfilters)
:param phase:
:param drop:
:param image_z:
:param height:
:param width:
:param scope:
:return:
"""
with tf.name_scope(scope):
W = weight_xavier_init(shape=kernal, n_inputs=kernal[0] * kernal[1] * kernal[2] * kernal[3],
n_outputs=kernal[-1], activefunction='relu', variable_name=scope + 'conv_W')
B = bias_variable([kernal[-1]], variable_name=scope + 'conv_B')
conv = conv3d(x, W) + B
conv = normalizationlayer(conv, is_train=phase, height=height, width=width, image_z=image_z, norm_type='group',
scope=scope)
conv = tf.nn.relu(conv)
return conv
