keras_yolo.py 文件源码

def yolo_body(inputs, num_anchors, num_classes):
    """Create YOLO_V2 model CNN body in Keras."""
    darknet = Model(inputs, darknet_body()(inputs))
    conv20 = compose(
        DarknetConv2D_BN_Leaky(1024, (3, 3)),
        DarknetConv2D_BN_Leaky(1024, (3, 3)))(darknet.output)

    conv13 = darknet.layers[43].output
    conv21 = DarknetConv2D_BN_Leaky(64, (1, 1))(conv13)
    # TODO: Allow Keras Lambda to use func arguments for output_shape?
    conv21_reshaped = Lambda(
        space_to_depth_x2,
        output_shape=space_to_depth_x2_output_shape,
        name='space_to_depth')(conv21)

    x = concatenate([conv21_reshaped, conv20])
    x = DarknetConv2D_BN_Leaky(1024, (3, 3))(x)
    x = DarknetConv2D(num_anchors * (num_classes + 5), (1, 1))(x)
    return Model(inputs, x)