UltraFace.h

//
//  UltraFace.hpp
//  UltraFaceTest
//
//  Created by vealocia on 2019/10/17.
//  Copyright © 2019 vealocia. All rights reserved.
//

#ifndef UltraFace_hpp
#define UltraFace_hpp

#pragma once

#include "gpu.h"
#include "net.h"
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>

#define num_featuremap 4
#define hard_nms 1
#define blending_nms 2 /* mix nms was been proposaled in paper blaze face, aims to minimize the temporal jitter*/

typedef struct FaceInfo
{
    float x1;
    float y1;
    float x2;
    float y2;
    float score;

    float *landmarks;
} FaceInfo;

class UltraFace
{
public:
    UltraFace(const std::string &bin_path, const std::string &param_path,
              int input_width, int input_length, int num_thread_ = 4, float score_threshold_ = 0.7, float iou_threshold_ = 0.3, int topk_ = -1);

    ~UltraFace();

    int detect(ncnn::Mat &img, std::vector<FaceInfo> &face_list);

private:
    void generateBBox(std::vector<FaceInfo> &bbox_collection, ncnn::Mat scores, ncnn::Mat boxes, float score_threshold, int num_anchors);

    void nms(std::vector<FaceInfo> &input, std::vector<FaceInfo> &output, int type = blending_nms);

private:
    ncnn::Net ultraface;

    int num_thread;
    int image_w;
    int image_h;

    int in_w;
    int in_h;
    int num_anchors;

    int topk;
    float score_threshold;
    float iou_threshold;

    const float mean_vals[3] = {127, 127, 127};
    const float norm_vals[3] = {1.0 / 128, 1.0 / 128, 1.0 / 128};

    const float center_variance = 0.1;
    const float size_variance = 0.2;
    const std::vector<std::vector<float>> min_boxes = {
        {10.0f, 16.0f, 24.0f},
        {32.0f, 48.0f},
        {64.0f, 96.0f},
        {128.0f, 192.0f, 256.0f}};
    const std::vector<float> strides = {8.0, 16.0, 32.0, 64.0};
    std::vector<std::vector<float>> featuremap_size;
    std::vector<std::vector<float>> shrinkage_size;
    std::vector<int> w_h_list;

    std::vector<std::vector<float>> priors = {};
};

#endif /* UltraFace_hpp */