Created by: peif1987

使用如下命令转换官方提供的ocr_det模型：

paddle_lite_opt  --model_file=./ch_det_mv3_db/model \
      --param_file=./ch_det_mv3_db/param  \
      --valid_targets=x86 \
      --optimize_out_type=protobuf \
      --optimize_out=ocr_det

提示错误如下：

This model is not supported, because 8 ops are not supported on 'x86'. These unsupported ops are: 'conv2d_transpose, elementwise_mul, exp, hard_sigmoid, hard_swish, nearest_interp, reciprocal, sigmoid'.