def Projection_block()

in face_decoder.py [0:0]

• 13 lines of code
• 2 McCabe index (conditional complexity)

	def Projection_block(self,face_shape,camera_scale,f_scale):

		# pre-defined camera focal for pespective projection
		focal = tf.constant(1015.0)
		focal = focal*f_scale
		focal = tf.reshape(focal,[-1,1])
		batchsize = tf.shape(focal)[0]

		# define camera position
		camera_pos = tf.reshape(tf.constant([0.0,0.0,10.0]),[1,1,3])*tf.reshape(camera_scale,[-1,1,1])
		reverse_z = tf.tile(tf.reshape(tf.constant([1.0,0,0,0,1,0,0,0,-1.0]),[1,3,3]),[tf.shape(face_shape)[0],1,1])

		# compute projection matrix
		p_matrix = tf.concat([focal,tf.zeros([batchsize,1]),112.*tf.ones([batchsize,1]),tf.zeros([batchsize,1]),focal,112.*tf.ones([batchsize,1]),tf.zeros([batchsize,2]),tf.ones([batchsize,1])],axis = 1)
		p_matrix = tf.reshape(p_matrix,[-1,3,3])

		# convert z in world space to the distance to camera
		face_shape = tf.matmul(face_shape,reverse_z) + camera_pos
		aug_projection = tf.matmul(face_shape,tf.transpose(p_matrix,[0,2,1]))

		# [batchsize, N,2] 2d face projection
		face_projection = aug_projection[:,:,0:2]/tf.reshape(aug_projection[:,:,2],[tf.shape(face_shape)[0],tf.shape(aug_projection)[1],1])


		return face_projection