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_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_sout.h>
  36 #include <vlc_vout.h>
  37
  38 #include "vlc_filter.h"
  39 #include "filter_picture.h"
  40
  41 #include <assert.h>
  42
  43 /*****************************************************************************
  44  * Local prototypes
  45  *****************************************************************************/
  46 static int  Create    ( vlc_object_t * );
  47 static void Destroy   ( vlc_object_t * );
  48
  49 static picture_t *Filter( filter_t *, picture_t * );
  50 static int CropCallback( vlc_object_t *, char const *,
  51                          vlc_value_t, vlc_value_t,
  52                          void * );
  53
  54 static void FilterSeamCarving( filter_t *, picture_t *, picture_t * );
  55
  56 /*****************************************************************************
  57  * Module descriptor
  58  *****************************************************************************/
  59
  60 #define FILTER_PREFIX "seamcarving-"
  61
  62 vlc_module_begin();
  63     set_description( N_("Seam Carving video filter") );
  64     set_shortname( N_( "Seam Carving" ));
  65     set_capability( "video filter2", 0 );
  66     set_category( CAT_VIDEO );
  67     set_subcategory( SUBCAT_VIDEO_VFILTER );
  68
  69     set_callbacks( Create, Destroy );
  70 vlc_module_end();
  71
  72 struct filter_sys_t
  73 {
  74     int *p_energy;
  75     int *p_grad;
  76
  77     int i_crop;
  78 };
  79
  80 static int Create( vlc_object_t *p_this )
  81 {
  82     filter_t *p_filter = (filter_t *)p_this;
  83
  84     /* Allocate structure */
  85     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
  86     if( p_filter->p_sys == NULL )
  87         return VLC_ENOMEM;
  88
  89     p_filter->pf_video_filter = Filter;
  90     p_filter->p_sys->p_energy = NULL;
  91     p_filter->p_sys->p_grad = NULL;
  92     p_filter->p_sys->i_crop = 0;
  93
  94     var_Create( p_filter, "crop", VLC_VAR_INTEGER|VLC_VAR_ISCOMMAND );
  95     var_AddCallback( p_filter, "crop", CropCallback, p_filter->p_sys );
  96
  97     return VLC_SUCCESS;
  98 }
  99
 100 static void Destroy( vlc_object_t *p_this )
 101 {
 102     filter_t *p_filter = (filter_t *)p_this;
 103
 104     free( p_filter->p_sys->p_energy );
 105     free( p_filter->p_sys->p_grad );
 106
 107     free( p_filter->p_sys );
 108 }
 109
 110 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 111 {
 112     picture_t *p_outpic;
 113
 114     if( !p_pic ) return NULL;
 115
 116     p_outpic = p_filter->pf_vout_buffer_new( p_filter );
 117     if( !p_outpic )
 118     {
 119         msg_Warn( p_filter, "can't get output picture" );
 120         if( p_pic->pf_release )
 121             p_pic->pf_release( p_pic );
 122         return NULL;
 123     }
 124
 125     FilterSeamCarving( p_filter, p_pic, p_outpic );
 126
 127     return CopyInfoAndRelease( p_outpic, p_pic );
 128 }
 129
 130 static inline int my_min3( int a, int b, int c );
 131 static inline int my_min( int a, int b );
 132 static int RemoveVerticalSeam( filter_t *p_filter, picture_t *p_inpic, picture_t *p_outpic, int i_src_visible );
 133
 134 //#define DRAW_GRADIENT
 135 //#define DRAW_ENERGY
 136 //#define DRAW_SEAM
 137
 138 static void FilterSeamCarving( filter_t *p_filter, picture_t *p_inpic,
 139                                                 picture_t *p_outpic )
 140 {
 141     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 142     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 143
 144     int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 145
 146     if( !p_filter->p_sys->p_energy )
 147         p_filter->p_sys->p_energy = (int*)malloc(i_src_pitch * i_num_lines * sizeof(int));
 148     if( !p_filter->p_sys->p_grad )
 149         p_filter->p_sys->p_grad = (int*)malloc(i_src_pitch * i_num_lines * sizeof(int));
 150
 151 //#if defined( DRAW_GRADIENT ) || defined( DRAW_ENERGY ) || defined( DRAW_SEAM )
 152     vlc_memcpy( p_outpic->p[Y_PLANE].p_pixels, p_inpic->p[Y_PLANE].p_pixels,
 153         p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 154 //#else
 155 //    vlc_memset( p_outpix, 0x80,
 156 //        p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 157 //#endif
 158     vlc_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
 159         p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 160     vlc_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
 161         p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 162
 163 #if defined( DRAW_GRADIENT ) || defined( DRAW_ENERGY ) || defined( DRAW_SEAM )
 164     i_src_visible = RemoveVerticalSeam( p_filter, p_outpic, p_outpic, i_src_visible );
 165 #else
 166     static int j = 1;
 167     static int k = 1;
 168     int i;
 169     if( p_filter->p_sys->i_crop != 0 )
 170         j = p_filter->p_sys->i_crop;
 171     for( i = 0; i < j; i++ )
 172     i_src_visible = RemoveVerticalSeam( p_filter, p_outpic, p_outpic, i_src_visible );
 173     int y;
 174     for( y = 0; y < p_outpic->p[Y_PLANE].i_lines; y++ )
 175         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 );
 176     j += k;
 177     if( j == 100 ) k = -1;
 178     if( j == 1 ) k = 1;
 179 #endif
 180 }
 181
 182 static int ComputeGradient( filter_t *p_filter, picture_t *p_inpic, int i_src_visible )
 183 {
 184     int x, y;
 185     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 186     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 187
 188     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 189     int *p_grad = p_filter->p_sys->p_grad;
 190
 191     for( y = 1; y < i_num_lines - 1;
 192          y++, p_grad += i_src_pitch )
 193     {
 194         /* Compute line y's gradient */
 195 #define GRADx( x ) \
 196             ( \
 197               abs( \
 198                  ( p_inpix[(y-1)*i_src_pitch+x-1] \
 199                    - p_inpix[(y+1)*i_src_pitch+x-1] ) \
 200                + ( ( p_inpix[(y-1)*i_src_pitch+x] \
 201                     - p_inpix[(y+1)*i_src_pitch+x] ) <<1 ) \
 202                + ( p_inpix[(y-1)*i_src_pitch+x+1] \
 203                    - p_inpix[(y+1)*i_src_pitch+x+1] ) \
 204               ) \
 205             + \
 206               abs( \
 207                  ( p_inpix[(y-1)*i_src_pitch+x-1] \
 208                    - p_inpix[(y-1)*i_src_pitch+x+1] ) \
 209                + ( ( p_inpix[y*i_src_pitch+x-1] \
 210                     - p_inpix[y*i_src_pitch+x+1] ) <<1 ) \
 211                + ( p_inpix[(y+1)*i_src_pitch+x-1] \
 212                    - p_inpix[(y+1)*i_src_pitch+x+1] ) \
 213               ) \
 214             )
 215         for( x = 1; x < i_src_visible - 1; x++ )
 216         {
 217             p_grad[x] = GRADx( x );
 218 #ifdef DRAW_GRADIENT
 219             p_outpix[y*i_src_pitch+x] = p_grad[x]>>3;
 220 #endif
 221         }
 222     }
 223     return 0;
 224 }
 225
 226 static int RemoveVerticalSeam( filter_t *p_filter, picture_t *p_inpic, picture_t *p_outpic, int i_src_visible )
 227 {
 228     int x, y;
 229     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 230     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 231
 232     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 233
 234     int *p_energy = p_filter->p_sys->p_energy;
 235     int *p_grad = p_filter->p_sys->p_grad;
 236
 237     ComputeGradient( p_filter, p_inpic, i_src_visible );
 238
 239     /** Compute the image's energy (using a sobel gradient as the base energy
 240      ** function) */
 241     /* Set the first energy line to 0 */
 242     memset( p_energy, 0, i_src_pitch*sizeof(int));
 243
 244     int *p_energy_prev = p_energy;
 245     for( y = 1; y < i_num_lines - 1;
 246          y++, p_energy_prev = p_energy, p_energy += i_src_pitch,
 247          p_grad += i_src_pitch )
 248     {
 249         /* Compute line y's minimum energy value for paths ending on
 250          * each x */
 251         x = 1;
 252         p_energy[x] = my_min( p_energy_prev[x  ]+p_grad[x  ],
 253                            p_energy_prev[x+1]+p_grad[x+1] );
 254         for( x = 2; x < i_src_visible - 2; x++ )
 255         {
 256             p_energy[x] = my_min3( p_energy_prev[x-1]+p_grad[x-1],
 257                                 p_energy_prev[x  ]+p_grad[x  ],
 258                                 p_energy_prev[x+1]+p_grad[x+1] );
 259         }
 260         p_energy[x] = my_min( p_energy_prev[x-1]+p_grad[x-1],
 261                            p_energy_prev[x  ]+p_grad[x  ] );
 262
 263 #ifdef DRAW_ENERGY
 264         int max = p_energy[1];
 265         for( x = 1; x < i_src_visible - 1; x++ )
 266             if( p_energy[x] > max ) max = p_energy[x];
 267         for( x = 1; x < i_src_visible - 1; x++ )
 268             p_outpix[y*i_src_pitch+x] = p_energy[x]*0xff/max;
 269 #endif
 270     }
 271
 272     /* Find the minimum energy point on the last line */
 273     y--;
 274     p_energy -= i_src_pitch;
 275     p_grad -= i_src_pitch;
 276
 277     int m = p_energy[1];
 278     int xmin = 1;
 279     for( x = 1; x < i_src_visible - 1; x++ )
 280     {
 281         if( p_energy[x] < m )
 282         {
 283             m = p_energy[x];
 284             xmin = x;
 285         }
 286     }
 287
 288 #ifdef DRAW_SEAM
 289     p_outpix[y*i_src_pitch+xmin] = 0xff;
 290     p_outpix[(y+1)*i_src_pitch+xmin] = 0xff;
 291 #else
 292     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 293     memmove( p_outpix+(y+1)*i_src_pitch+xmin, p_outpix+(y+1)*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 294 #endif
 295
 296     p_energy -= i_src_pitch;
 297     for( ; y>1; y--, p_energy -= i_src_pitch, p_grad -= i_src_pitch )
 298     {
 299         if( m != p_energy[xmin]+p_grad[xmin] )
 300         {
 301             if( xmin > 1 && m == p_energy[xmin-1]+p_grad[xmin-1] )
 302             {
 303                 xmin--;
 304             }
 305             else if( xmin < i_src_visible - 2 && m == p_energy[xmin+1]+p_grad[xmin+1] )
 306             {
 307                 xmin++;
 308             }
 309             else
 310             {
 311                 printf("Alarm! %d\n" ,y);
 312                 //assert( 0 );
 313             }
 314         }
 315         m = p_energy[xmin];
 316 #ifdef DRAW_SEAM
 317         p_outpix[y*i_src_pitch+xmin] = 0xff;
 318 #else
 319         memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 320 #endif
 321     }
 322 #ifdef DRAW_SEAM
 323     p_outpix[y*i_src_pitch+xmin] = 0xff;
 324 #else
 325     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 326 #endif
 327     y--;
 328 #ifdef DRAW_SEAM
 329     p_outpix[y*i_src_pitch+xmin] = 0xff;
 330 #else
 331     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 332 #endif
 333
 334 #if defined( DRAW_SEAM )
 335     return i_src_visible;
 336 #else
 337     return i_src_visible-1;
 338 #endif
 339 }
 340
 341 static inline int my_min3( int a, int b, int c )
 342 {
 343     if( a < b )
 344     {
 345         if( a < c ) return a;
 346         return c;
 347     }
 348     if( b < c ) return b;
 349     return c;
 350 }
 351 static inline int my_min( int a, int b )
 352 {
 353     return a < b ? a : b;
 354 }
 355
 356 static int CropCallback( vlc_object_t *p_this, char const *psz_var,
 357                                 vlc_value_t oldval, vlc_value_t newval,
 358                                 void *p_data )
 359 {
 360     VLC_UNUSED(p_this); VLC_UNUSED(psz_var); VLC_UNUSED(oldval);
 361     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 362     p_sys->i_crop = newval.i_int;
 363     return VLC_SUCCESS;
 364 }