oflow.h

// Class implements main flow computation loop over all scales

#ifndef OFC_HEADER
#define OFC_HEADER

using std::cout;
using std::endl;

namespace OFC
{

typedef __v4sf v4sf;
  

typedef struct 
{
  int width;                // image width, does not include '2*imgpadding', but includes original padding to ensure integer divisible image width and height
  int height;               // image height, does not include '2*imgpadding', but includes original padding to ensure integer divisible image width and height
  int imgpadding;           // image padding in pixels at all sides, images padded with replicated border, gradients padded with zero, ADD THIS ONLY WHEN ADDRESSING THE IMAGE OR GRADIENT
  float tmp_lb;             // lower bound for valid image region, pre-compute for image padding to avoid border check 
  float tmp_ubw;            // upper width bound for valid image region, pre-compute for image padding to avoid border check 
  float tmp_ubh;            // upper height bound for valid image region, pre-compute for image padding to avoid border check 
  int tmp_w;                // width + 2*imgpadding
  int tmp_h;                // height + 2*imgpadding
  float sc_fct;             // scaling factor at current scale  
  int curr_lv;              // current level
  int camlr;                // 0: left camera, 1: right camera, used only for depth, to restrict sideways patch motion
} camparam ;

typedef struct
{
  // Explicitly set parameters:
  int sc_f;             // first (coarsest) scale
  int sc_l;             // last (finest) scale
  int p_samp_s;         // patch size (edge length in pixels)  
  int max_iter;         // max. iterations on one scale
  int min_iter;         // min. iterations on one scale
  float dp_thresh;      // minimum rate of change of delta_p before descending one level, e.g. .1 :  change scales when norm(delta_p_last)/norm(delta_p_init) < .1
  float dr_thresh;      // minimum rate of change of residual within 3-iterations-window before descending one level, e.g. .8 :  res_new/res_old >  * .8, SET HIGH (1e10) TO DISABLE
  float res_thresh;     // if (mean absolute) residual falls below this threshold, terminate iterations on current scale, IGNORES MIN_ITER , SET TO LOW (1e-10) TO DISABLE
  int patnorm;          // Use patch mean-normalization
  int verbosity;        // Verbosity, 0: plot nothing, 1: final internal timing 2: complete iteration timing, (UNCOMMENTED -> 3: Display flow scales, 4: Display flow scale iterations)
  bool usefbcon;        // use forward-backward flow merging 
  int costfct;          // Cost function: 0: L2-Norm, 1: L1-Norm, 2: PseudoHuber-Norm 
  bool usetvref;        // TV parameters
  float tv_alpha;
  float tv_gamma;
  float tv_delta;
  int tv_innerit;
  int tv_solverit;
  float tv_sor;         // Successive-over-relaxation weight
  
  // Automatically set parameters / fixed parameters
  int nop;                      // number of parameters per pixel, 1 for depth, 2 for optical flow, 4 for scene flow
  float patove;                 // point/line padding to all sides (px)
  float outlierthresh;          // displacement threshold (in px) before a patch is flagged as outlier
  int steps;                    // horizontal and vertical distance (in px) between patch centers
  int novals;                   // number of points in patch (=p_samp_s*p_samp_s) 
  int noc;                      // number of channels in image and gradients 
  int noscales;                 // total number of scales
  float minerrval = 2.0f;       // 1/max(this, error) for pixel averaging weight
  float normoutlier = 5.0f;     // norm error threshold for huber norm
  
  // Helper variables
  v4sf zero     = (v4sf) {0.0f, 0.0f, 0.0f, 0.0f};
  v4sf negzero  = (v4sf) {-0.0f, -0.0f, -0.0f, -0.0f};
  v4sf half     = (v4sf) {0.5f, 0.5f, 0.5f, 0.5f};
  v4sf ones     = (v4sf) {1.0f, 1.0f, 1.0f, 1.0f};
  v4sf twos     = (v4sf) {2.0f, 2.0f, 2.0f, 2.0f};
  v4sf fours    = (v4sf) {4.0f, 4.0f, 4.0f, 4.0f};  
  v4sf normoutlier_tmpbsq;   
  v4sf normoutlier_tmp2bsq;  
  v4sf normoutlier_tmp4bsq;  
  
} optparam;



class OFClass
{

public:
  OFClass(const float ** im_ao_in, const float ** im_ao_dx_in, const float ** im_ao_dy_in, // expects #sc_f_in pointers to float arrays for images and gradients. 
                                                                                       // E.g. im_ao[sc_f_in] will be used as coarsest coarsest, im_ao[sc_l_in] as finest scale
                                                                                       // im_ao[  (sc_l_in-1) : 0 ] can be left as nullptr pointers
                                                                                       // IMPORTANT assumption: mod(width,2^sc_f_in)==0  AND mod(height,2^sc_f_in)==0, 
          const float ** im_bo_in, const float ** im_bo_dx_in, const float ** im_bo_dy_in,
          const int imgpadding_in,
          float * outflow,          // Output-flow:         has to be of size to fit the last  computed OF scale [width / 2^(last scale)   , height / 2^(last scale)]   , 1 channel depth / 2 for OF
          const float * initflow,   // Initialization-flow: has to be of size to fit the first computed OF scale [width / 2^(first scale+1), height / 2^(first scale+1)], 1 channel depth / 2 for OF
          const int width_in, const int height_in, 
          const int sc_f_in, const int sc_l_in,
          const int max_iter_in, const int min_iter_in,
          const float  dp_thresh_in,
          const float  dr_thresh_in,
          const float res_thresh_in,            
          const int padval_in,
          const float patove_in,
          const bool usefbcon_in,
          const int costfct_in, 
          const int noc_in,
          const int patnorm_in,
          const bool usetvref_in,
          const float tv_alpha_in,
          const float tv_gamma_in,
          const float tv_delta_in,
          const int tv_innerit_in,
          const int tv_solverit_in,
          const float tv_sor_in,
          const int verbosity_in);
  
private:

  // needed for verbosity >= 3, DISVISUAL
  //void DisplayDrawPatchBoundary(cv::Mat img, const Eigen::Vector2f pt, const float sc);

  const float ** im_ao, ** im_ao_dx, ** im_ao_dy;
  const float ** im_bo, ** im_bo_dx, ** im_bo_dy;
  
  optparam op;                    // Struct for pptimization parameters
  std::vector<camparam> cpl, cpr; // Struct (for each scale) for camera/image parameter
};


}

#endif /* OFC_HEADER */