src/localmotion2transform.h

   1 /*
   2  * localmotion2transform.h
   3  *
   4  *  Copyright (C) Georg Martius - January 2013
   5  *   georg dot martius at web dot de
   6  *
   7  *  This file is part of vid.stab video stabilization library
   8  *
   9  *  vid.stab is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License,
  11  *  as published by the Free Software Foundation; either version 2, or
  12  *  (at your option) any later version.
  13  *
  14  *  vid.stab is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with GNU Make; see the file COPYING.  If not, write to
  21  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  */
  24
  25 #ifndef __LOCALMOTION2TRANSFORM_H
  26 #define __LOCALMOTION2TRANSFORM_H
  27
  28
  29 #include "transform.h"
  30 #include "transformtype.h"
  31 #include "serialize.h"
  32
  33
  34 /** converts for each frame the localmotions into a transform
  35  */
  36 int vsLocalmotions2Transforms(VSTransformData* td,
  37                               const VSManyLocalMotions* motions,
  38                               VSTransformations* trans );
  39
  40 /** calculates rotation angle for the given transform and
  41  * field with respect to the given center-point
  42  */
  43 double vsCalcAngle(const LocalMotion* lm, int center_x, int center_y);
  44
  45 /** calculates the transformation that caused the observed motions.
  46     Using a simple cleaned-means approach to eliminate outliers.
  47     translation and rotation is calculated.
  48     calculate shift as cleaned mean of all local motions
  49     calculate rotation angle of each field in respect to center of fields
  50     after shift removal
  51     calculate rotation angle as cleaned mean of all angles
  52     compensate for possibly off-center rotation
  53 */
  54 VSTransform vsSimpleMotionsToTransform(VSFrameInfo fi, const char* modname,
  55                                        const LocalMotions* motions);
  56
  57
  58 /** calculates the transformation that caused the observed motions.
  59     Using a gradient descent algorithm.
  60     Outliers are removed by repeated gaussianizing error distribution.
  61     (File for exporting transforms)
  62 */
  63 VSTransform vsMotionsToTransform(VSTransformData* td,
  64                                  const LocalMotions* motions,
  65                                  FILE* f);
  66
  67
  68
  69 /** general purpose gradient descent algorithm
  70
  71  * Parameters:
  72  *       eval: evaluation function (value/energy to be minimized)
  73  *     params: initial starting parameters
  74  *        dat: custom data for eval function
  75  *          N: number of iterations (100)
  76  *  stepsizes: stepsizes for each dimension of the gradient {0.1,0.1...} (will be deleted)
  77  *  threshold: value below which the value/energy is considered to be minimized (0)
  78  *   residual: residual value (call by reference) (can be NULL)
  79  * Return Value:
  80  *     Optimized parameters
  81  */
  82 VSArray vsGradientDescent(double (*eval)(VSArray, void*),
  83                          VSArray params, void* dat,
  84                          int N, VSArray stepsizes, double threshold, double* residual);
  85
  86 #endif