git.sesse.net Git - vlc/blob - modules/video_filter/seamcarving.c

   1 /*****************************************************************************
   2  * seamcarving.c: "Seam Carving for Content-Aware Image Resizing"
   3  * Based on paper by Shai Avidan and Ariel Shamir.
   4  *****************************************************************************
   5  * Copyright (C) 2007 the VideoLAN team
   6  * $Id$
   7  *
   8  * Authors: Antoine Cellerier <dionoea -at- videolan -dot- org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc/vlc.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_sout.h>
  36 #include <vlc_vout.h>
  37
  38 #include "vlc_filter.h"
  39
  40 #include <assert.h>
  41
  42 /*****************************************************************************
  43  * Local prototypes
  44  *****************************************************************************/
  45 static int  Create    ( vlc_object_t * );
  46 static void Destroy   ( vlc_object_t * );
  47
  48 static picture_t *Filter( filter_t *, picture_t * );
  49 static int CropCallback( vlc_object_t *, char const *,
  50                          vlc_value_t, vlc_value_t,
  51                          void * );
  52
  53 static void FilterSeamCarving( filter_t *, picture_t *, picture_t * );
  54
  55 /*****************************************************************************
  56  * Module descriptor
  57  *****************************************************************************/
  58
  59 #define FILTER_PREFIX "seamcarving-"
  60
  61 vlc_module_begin();
  62     set_description( N_("Seam Carving video filter") );
  63     set_shortname( N_( "Seam Carving" ));
  64     set_capability( "video filter2", 0 );
  65     set_category( CAT_VIDEO );
  66     set_subcategory( SUBCAT_VIDEO_VFILTER );
  67
  68     set_callbacks( Create, Destroy );
  69 vlc_module_end();
  70
  71 static const char *ppsz_filter_options[] = {
  72     NULL
  73 };
  74
  75 struct filter_sys_t
  76 {
  77     int *p_energy;
  78     int *p_grad;
  79
  80     int i_crop;
  81 };
  82
  83 static int Create( vlc_object_t *p_this )
  84 {
  85     filter_t *p_filter = (filter_t *)p_this;
  86
  87     /* Allocate structure */
  88     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
  89     if( p_filter->p_sys == NULL )
  90     {
  91         msg_Err( p_filter, "out of memory" );
  92         return VLC_ENOMEM;
  93     }
  94
  95     p_filter->pf_video_filter = Filter;
  96     p_filter->p_sys->p_energy = NULL;
  97     p_filter->p_sys->p_grad = NULL;
  98     p_filter->p_sys->i_crop = 0;
  99
 100     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 101                    p_filter->p_cfg );
 102
 103     var_Create( p_filter, "crop", VLC_VAR_INTEGER|VLC_VAR_ISCOMMAND );
 104     var_AddCallback( p_filter, "crop", CropCallback, p_filter->p_sys );
 105
 106     return VLC_SUCCESS;
 107 }
 108
 109 static void Destroy( vlc_object_t *p_this )
 110 {
 111     filter_t *p_filter = (filter_t *)p_this;
 112
 113     free( p_filter->p_sys->p_energy );
 114     free( p_filter->p_sys->p_grad );
 115
 116     free( p_filter->p_sys );
 117 }
 118
 119 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 120 {
 121     picture_t *p_outpic;
 122
 123     if( !p_pic ) return NULL;
 124
 125     p_outpic = p_filter->pf_vout_buffer_new( p_filter );
 126     if( !p_outpic )
 127     {
 128         msg_Warn( p_filter, "can't get output picture" );
 129         if( p_pic->pf_release )
 130             p_pic->pf_release( p_pic );
 131         return NULL;
 132     }
 133
 134     FilterSeamCarving( p_filter, p_pic, p_outpic );
 135
 136     p_outpic->date = p_pic->date;
 137     p_outpic->b_force = p_pic->b_force;
 138     p_outpic->i_nb_fields = p_pic->i_nb_fields;
 139     p_outpic->b_progressive = p_pic->b_progressive;
 140     p_outpic->b_top_field_first = p_pic->b_top_field_first;
 141
 142     if( p_pic->pf_release )
 143         p_pic->pf_release( p_pic );
 144
 145     return p_outpic;
 146 }
 147
 148 static inline int my_min3( int a, int b, int c );
 149 static inline int my_min( int a, int b );
 150 static int RemoveVerticalSeam( filter_t *p_filter, picture_t *p_inpic, picture_t *p_outpic, int i_src_visible );
 151
 152 //#define DRAW_GRADIENT
 153 //#define DRAW_ENERGY
 154 //#define DRAW_SEAM
 155
 156 static void FilterSeamCarving( filter_t *p_filter, picture_t *p_inpic,
 157                                                 picture_t *p_outpic )
 158 {
 159     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 160     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 161
 162     int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 163
 164     if( !p_filter->p_sys->p_energy )
 165         p_filter->p_sys->p_energy = (int*)malloc(i_src_pitch * i_num_lines * sizeof(int));
 166     if( !p_filter->p_sys->p_grad )
 167         p_filter->p_sys->p_grad = (int*)malloc(i_src_pitch * i_num_lines * sizeof(int));
 168
 169 //#if defined( DRAW_GRADIENT ) || defined( DRAW_ENERGY ) || defined( DRAW_SEAM )
 170     vlc_memcpy( p_outpic->p[Y_PLANE].p_pixels, p_inpic->p[Y_PLANE].p_pixels,
 171         p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 172 //#else
 173 //    vlc_memset( p_outpix, 0x80,
 174 //        p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 175 //#endif
 176     vlc_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
 177         p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 178     vlc_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
 179         p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 180
 181 #if defined( DRAW_GRADIENT ) || defined( DRAW_ENERGY ) || defined( DRAW_SEAM )
 182     i_src_visible = RemoveVerticalSeam( p_filter, p_outpic, p_outpic, i_src_visible );
 183 #else
 184     static int j = 1;
 185     static int k = 1;
 186     int i;
 187     if( p_filter->p_sys->i_crop != 0 )
 188         j = p_filter->p_sys->i_crop;
 189     for( i = 0; i < j; i++ )
 190     i_src_visible = RemoveVerticalSeam( p_filter, p_outpic, p_outpic, i_src_visible );
 191     int y;
 192     for( y = 0; y < p_outpic->p[Y_PLANE].i_lines; y++ )
 193         vlc_memset( p_outpic->p[Y_PLANE].p_pixels + y*p_outpic->p[Y_PLANE].i_pitch + i_src_visible, 0x00, p_outpic->p[Y_PLANE].i_pitch - i_src_visible );
 194     j += k;
 195     if( j == 100 ) k = -1;
 196     if( j == 1 ) k = 1;
 197 #endif
 198 }
 199
 200 static int ComputeGradient( filter_t *p_filter, picture_t *p_inpic, int i_src_visible )
 201 {
 202     int x, y;
 203     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 204     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 205
 206     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 207     int *p_grad = p_filter->p_sys->p_grad;
 208
 209     for( y = 1; y < i_num_lines - 1;
 210          y++, p_grad += i_src_pitch )
 211     {
 212         /* Compute line y's gradient */
 213 #define GRADx( x ) \
 214             ( \
 215               abs( \
 216                  ( p_inpix[(y-1)*i_src_pitch+x-1] \
 217                    - p_inpix[(y+1)*i_src_pitch+x-1] ) \
 218                + ( ( p_inpix[(y-1)*i_src_pitch+x] \
 219                     - p_inpix[(y+1)*i_src_pitch+x] ) <<1 ) \
 220                + ( p_inpix[(y-1)*i_src_pitch+x+1] \
 221                    - p_inpix[(y+1)*i_src_pitch+x+1] ) \
 222               ) \
 223             + \
 224               abs( \
 225                  ( p_inpix[(y-1)*i_src_pitch+x-1] \
 226                    - p_inpix[(y-1)*i_src_pitch+x+1] ) \
 227                + ( ( p_inpix[y*i_src_pitch+x-1] \
 228                     - p_inpix[y*i_src_pitch+x+1] ) <<1 ) \
 229                + ( p_inpix[(y+1)*i_src_pitch+x-1] \
 230                    - p_inpix[(y+1)*i_src_pitch+x+1] ) \
 231               ) \
 232             )
 233         for( x = 1; x < i_src_visible - 1; x++ )
 234         {
 235             p_grad[x] = GRADx( x );
 236 #ifdef DRAW_GRADIENT
 237             p_outpix[y*i_src_pitch+x] = p_grad[x]>>3;
 238 #endif
 239         }
 240     }
 241     return 0;
 242 }
 243
 244 static int RemoveVerticalSeam( filter_t *p_filter, picture_t *p_inpic, picture_t *p_outpic, int i_src_visible )
 245 {
 246     int x, y;
 247     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 248     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 249
 250     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 251
 252     int *p_energy = p_filter->p_sys->p_energy;
 253     int *p_grad = p_filter->p_sys->p_grad;
 254
 255     ComputeGradient( p_filter, p_inpic, i_src_visible );
 256
 257     /** Compute the image's energy (using a sobel gradient as the base energy
 258      ** function) */
 259     /* Set the first energy line to 0 */
 260     memset( p_energy, 0, i_src_pitch*sizeof(int));
 261
 262     int *p_energy_prev = p_energy;
 263     for( y = 1; y < i_num_lines - 1;
 264          y++, p_energy_prev = p_energy, p_energy += i_src_pitch,
 265          p_grad += i_src_pitch )
 266     {
 267         /* Compute line y's minimum energy value for paths ending on
 268          * each x */
 269         x = 1;
 270         p_energy[x] = my_min( p_energy_prev[x  ]+p_grad[x  ],
 271                            p_energy_prev[x+1]+p_grad[x+1] );
 272         for( x = 2; x < i_src_visible - 2; x++ )
 273         {
 274             p_energy[x] = my_min3( p_energy_prev[x-1]+p_grad[x-1],
 275                                 p_energy_prev[x  ]+p_grad[x  ],
 276                                 p_energy_prev[x+1]+p_grad[x+1] );
 277         }
 278         p_energy[x] = my_min( p_energy_prev[x-1]+p_grad[x-1],
 279                            p_energy_prev[x  ]+p_grad[x  ] );
 280
 281 #ifdef DRAW_ENERGY
 282         int max = p_energy[1];
 283         for( x = 1; x < i_src_visible - 1; x++ )
 284             if( p_energy[x] > max ) max = p_energy[x];
 285         for( x = 1; x < i_src_visible - 1; x++ )
 286             p_outpix[y*i_src_pitch+x] = p_energy[x]*0xff/max;
 287 #endif
 288     }
 289
 290     /* Find the minimum energy point on the last line */
 291     y--;
 292     p_energy -= i_src_pitch;
 293     p_grad -= i_src_pitch;
 294
 295     int m = p_energy[1];
 296     int xmin = 1;
 297     for( x = 1; x < i_src_visible - 1; x++ )
 298     {
 299         if( p_energy[x] < m )
 300         {
 301             m = p_energy[x];
 302             xmin = x;
 303         }
 304     }
 305
 306 #ifdef DRAW_SEAM
 307     p_outpix[y*i_src_pitch+xmin] = 0xff;
 308     p_outpix[(y+1)*i_src_pitch+xmin] = 0xff;
 309 #else
 310     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 311     memmove( p_outpix+(y+1)*i_src_pitch+xmin, p_outpix+(y+1)*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 312 #endif
 313
 314     p_energy -= i_src_pitch;
 315     for( ; y>1; y--, p_energy -= i_src_pitch, p_grad -= i_src_pitch )
 316     {
 317         if( m != p_energy[xmin]+p_grad[xmin] )
 318         {
 319             if( xmin > 1 && m == p_energy[xmin-1]+p_grad[xmin-1] )
 320             {
 321                 xmin--;
 322             }
 323             else if( xmin < i_src_visible - 2 && m == p_energy[xmin+1]+p_grad[xmin+1] )
 324             {
 325                 xmin++;
 326             }
 327             else
 328             {
 329                 printf("Alarm! %d\n" ,y);
 330                 //assert( 0 );
 331             }
 332         }
 333         m = p_energy[xmin];
 334 #ifdef DRAW_SEAM
 335         p_outpix[y*i_src_pitch+xmin] = 0xff;
 336 #else
 337         memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 338 #endif
 339     }
 340 #ifdef DRAW_SEAM
 341     p_outpix[y*i_src_pitch+xmin] = 0xff;
 342 #else
 343     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 344 #endif
 345     y--;
 346 #ifdef DRAW_SEAM
 347     p_outpix[y*i_src_pitch+xmin] = 0xff;
 348 #else
 349     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 350 #endif
 351
 352 #if defined( DRAW_SEAM )
 353     return i_src_visible;
 354 #else
 355     return i_src_visible-1;
 356 #endif
 357 }
 358
 359 static inline int my_min3( int a, int b, int c )
 360 {
 361     if( a < b )
 362     {
 363         if( a < c ) return a;
 364         return c;
 365     }
 366     if( b < c ) return b;
 367     return c;
 368 }
 369 static inline int my_min( int a, int b )
 370 {
 371     return a < b ? a : b;
 372 }
 373
 374 static int CropCallback( vlc_object_t *p_this, char const *psz_var,
 375                                 vlc_value_t oldval, vlc_value_t newval,
 376                                 void *p_data )
 377 {
 378     VLC_UNUSED(p_this); VLC_UNUSED(psz_var); VLC_UNUSED(oldval);
 379     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 380     p_sys->i_crop = newval.i_int;
 381     return VLC_SUCCESS;
 382 }