localmotion2transform.h

/*
 * localmotion2transform.h
 *
 *  Copyright (C) Georg Martius - January 2013
 *   georg dot martius at web dot de
 *
 *  This file is part of vid.stab video stabilization library
 *
 *  vid.stab is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License,
 *  as published by the Free Software Foundation; either version 2, or
 *  (at your option) any later version.
 *
 *  vid.stab is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GNU Make; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#ifndef __LOCALMOTION2TRANSFORM_H
#define __LOCALMOTION2TRANSFORM_H


#include "transform.h"
#include "transformtype.h"
#include "serialize.h"


/** converts for each frame the localmotions into a transform
 */
int vsLocalmotions2Transforms(VSTransformData* td,
                              const VSManyLocalMotions* motions,
                              VSTransformations* trans );

/** calculates rotation angle for the given transform and
 * field with respect to the given center-point
 */
double vsCalcAngle(const LocalMotion* lm, int center_x, int center_y);

/** calculates the transformation that caused the observed motions.
    Using a simple cleaned-means approach to eliminate outliers.
    translation and rotation is calculated.
    calculate shift as cleaned mean of all local motions
    calculate rotation angle of each field in respect to center of fields
    after shift removal
    calculate rotation angle as cleaned mean of all angles
    compensate for possibly off-center rotation
*/
VSTransform vsSimpleMotionsToTransform(VSFrameInfo fi, const char* modname,
                                       const LocalMotions* motions);


/** calculates the transformation that caused the observed motions.
    Using a gradient descent algorithm.
    Outliers are removed by repeated gaussianizing error distribution.
    (File for exporting transforms)
*/
VSTransform vsMotionsToTransform(VSTransformData* td,
                                 const LocalMotions* motions,
                                 FILE* f);



/** general purpose gradient descent algorithm

 * Parameters:
 *       eval: evaluation function (value/energy to be minimized)
 *     params: initial starting parameters
 *        dat: custom data for eval function
 *          N: number of iterations (100)
 *  stepsizes: stepsizes for each dimension of the gradient {0.1,0.1...} (will be deleted)
 *  threshold: value below which the value/energy is considered to be minimized (0)
 *   residual: residual value (call by reference) (can be NULL)
 * Return Value:
 *     Optimized parameters
 */
VSArray vsGradientDescent(double (*eval)(VSArray, void*),
                         VSArray params, void* dat,
                         int N, VSArray stepsizes, double threshold, double* residual);

#endif