Tools to convert ONNX files (NCHW) to TensorFlow format (NHWC)

• Support for --replace_erf_to_pseudo_erf option
• Replace Erf not supported by TFLite with a primitive approximation
  • approximate expression

    eps = 1e-11
    x_abs = tf.math.abs(input_tensor)+eps
    sign = tf.math.divide(input_tensor, x_abs)
    a1 =  0.254829592
    a2 = -0.284496736
    a3 =  1.421413741
    a4 = -1.453152027
    a5 =  1.061405429
    p  =  0.3275911
    t = 1.0/(1.0 + p*x_abs)
    y = 1.0 - (((((a5*t + a4)*t) + a3)*t + a2)*t + a1)*t*tf.math.exp(-x_abs*x_abs)
    erf_tensor = sign*y
    tf_layers_dict[graph_node_output.name]['tf_node'] = erf_tensor
    

Full Changelog: https://github.com/PINTO0309/onnx2tf/compare/1.1.30...1.1.31