c++代码楼主测试过了吗，好几个明显的bug是跑不过的。

this->input_image.resize(3 * image_area);
size_t single_chn_size = image_area * sizeof(float);    
memcpy(this->input_image.data(), (float *)bgrChannels[0].data, single_chn_size);           //明显的越界
memcpy(this->input_image.data() + image_area, (float *)bgrChannels[1].data, single_chn_size);
memcpy(this->input_image.data() + image_area * 2, (float *)bgrChannels[2].data, single_chn_size);