util.py 文件源码

def bilinearResize(images, ratiox, ratioy):
    '''
    images: 4D image batch
    ratiox, ratioy: magnification ratio. Positive integer.
    '''

    b, h, w, c = [v.value for v in images.get_shape()]

    sidex = 2 * ratiox - 1
    sidey = 2 * ratioy - 1

    interpolatex = np.true_divide((ratiox - np.abs(np.arange(sidex) - ratiox + 1)), ratiox)
    interpolatey = np.true_divide((ratioy - np.abs(np.arange(sidey) - ratioy + 1)), ratioy)
    weight = np.outer(interpolatex, interpolatey).astype(np.float32)

    weights = np.zeros((sidex,sidey,c,c), dtype=np.float32)   
    for i in range(c):
        weights[:,:,i,i] = weight

    out_shape = [b, h*ratiox, w*ratioy, c]
    strides = [1, ratiox, ratioy, 1]
    kernel = tf.constant(weights, name='bilinear_convt_weights')

    return tf.nn.conv2d_transpose(images, weights, 
            out_shape, strides=strides, padding='SAME')