initialize deconvolution weights，i can't understand why you do it as the following

[jupyzhu]

def get_deconv_filter(self, f_shape):
width = f_shape[0]
heigh = f_shape[0]
f = ceil(width/2.0)
c = (2 * f - 1 - f % 2) / (2.0 * f)
bilinear = np.zeros([f_shape[0], f_shape[1]])
for x in range(width):
for y in range(heigh):
value = (1 - abs(x / f - c)) * (1 - abs(y / f - c))
bilinear[x, y] = value
weights = np.zeros(f_shape)
for i in range(f_shape[2]):
weights[:, :, i, i] = bilinear

code above is from the fcn8_vgg.py，i don not have the ideal that why f,c and value to be computed as your way. what is the meaning for those formulas?