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         picture_Release( p_pic );
 121         return NULL;
 122     }
 123
 124     FilterSeamCarving( p_filter, p_pic, p_outpic );
 125
 126     return CopyInfoAndRelease( p_outpic, p_pic );
 127 }
 128
 129 static inline int my_min3( int a, int b, int c );
 130 static inline int my_min( int a, int b );
 131 static int RemoveVerticalSeam( filter_t *p_filter, picture_t *p_inpic, picture_t *p_outpic, int i_src_visible );
 132
 133 //#define DRAW_GRADIENT
 134 //#define DRAW_ENERGY
 135 //#define DRAW_SEAM
 136
 137 static void FilterSeamCarving( filter_t *p_filter, picture_t *p_inpic,
 138                                                 picture_t *p_outpic )
 139 {
 140     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 141     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 142
 143     int i_src_visible = p_inpic->p[Y_PLANE].i_visible_pitch;
 144
 145     if( !p_filter->p_sys->p_energy )
 146         p_filter->p_sys->p_energy = (int*)malloc(i_src_pitch * i_num_lines * sizeof(int));
 147     if( !p_filter->p_sys->p_grad )
 148         p_filter->p_sys->p_grad = (int*)malloc(i_src_pitch * i_num_lines * sizeof(int));
 149
 150 //#if defined( DRAW_GRADIENT ) || defined( DRAW_ENERGY ) || defined( DRAW_SEAM )
 151     vlc_memcpy( p_outpic->p[Y_PLANE].p_pixels, p_inpic->p[Y_PLANE].p_pixels,
 152         p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 153 //#else
 154 //    vlc_memset( p_outpix, 0x80,
 155 //        p_outpic->p[Y_PLANE].i_lines * p_outpic->p[Y_PLANE].i_pitch );
 156 //#endif
 157     vlc_memset( p_outpic->p[U_PLANE].p_pixels, 0x80,
 158         p_outpic->p[U_PLANE].i_lines * p_outpic->p[U_PLANE].i_pitch );
 159     vlc_memset( p_outpic->p[V_PLANE].p_pixels, 0x80,
 160         p_outpic->p[V_PLANE].i_lines * p_outpic->p[V_PLANE].i_pitch );
 161
 162 #if defined( DRAW_GRADIENT ) || defined( DRAW_ENERGY ) || defined( DRAW_SEAM )
 163     i_src_visible = RemoveVerticalSeam( p_filter, p_outpic, p_outpic, i_src_visible );
 164 #else
 165     static int j = 1;
 166     static int k = 1;
 167     int i;
 168     if( p_filter->p_sys->i_crop != 0 )
 169         j = p_filter->p_sys->i_crop;
 170     for( i = 0; i < j; i++ )
 171     i_src_visible = RemoveVerticalSeam( p_filter, p_outpic, p_outpic, i_src_visible );
 172     int y;
 173     for( y = 0; y < p_outpic->p[Y_PLANE].i_lines; y++ )
 174         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 );
 175     j += k;
 176     if( j == 100 ) k = -1;
 177     if( j == 1 ) k = 1;
 178 #endif
 179 }
 180
 181 static int ComputeGradient( filter_t *p_filter, picture_t *p_inpic, int i_src_visible )
 182 {
 183     int x, y;
 184     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 185     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 186
 187     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 188     int *p_grad = p_filter->p_sys->p_grad;
 189
 190     for( y = 1; y < i_num_lines - 1;
 191          y++, p_grad += i_src_pitch )
 192     {
 193         /* Compute line y's gradient */
 194 #define GRADx( x ) \
 195             ( \
 196               abs( \
 197                  ( p_inpix[(y-1)*i_src_pitch+x-1] \
 198                    - p_inpix[(y+1)*i_src_pitch+x-1] ) \
 199                + ( ( p_inpix[(y-1)*i_src_pitch+x] \
 200                     - p_inpix[(y+1)*i_src_pitch+x] ) <<1 ) \
 201                + ( p_inpix[(y-1)*i_src_pitch+x+1] \
 202                    - p_inpix[(y+1)*i_src_pitch+x+1] ) \
 203               ) \
 204             + \
 205               abs( \
 206                  ( p_inpix[(y-1)*i_src_pitch+x-1] \
 207                    - p_inpix[(y-1)*i_src_pitch+x+1] ) \
 208                + ( ( p_inpix[y*i_src_pitch+x-1] \
 209                     - p_inpix[y*i_src_pitch+x+1] ) <<1 ) \
 210                + ( p_inpix[(y+1)*i_src_pitch+x-1] \
 211                    - p_inpix[(y+1)*i_src_pitch+x+1] ) \
 212               ) \
 213             )
 214         for( x = 1; x < i_src_visible - 1; x++ )
 215         {
 216             p_grad[x] = GRADx( x );
 217 #ifdef DRAW_GRADIENT
 218             p_outpix[y*i_src_pitch+x] = p_grad[x]>>3;
 219 #endif
 220         }
 221     }
 222     return 0;
 223 }
 224
 225 static int RemoveVerticalSeam( filter_t *p_filter, picture_t *p_inpic, picture_t *p_outpic, int i_src_visible )
 226 {
 227     int x, y;
 228     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 229     const int i_num_lines = p_inpic->p[Y_PLANE].i_visible_lines;
 230
 231     uint8_t *p_outpix = p_outpic->p[Y_PLANE].p_pixels;
 232
 233     int *p_energy = p_filter->p_sys->p_energy;
 234     int *p_grad = p_filter->p_sys->p_grad;
 235
 236     ComputeGradient( p_filter, p_inpic, i_src_visible );
 237
 238     /** Compute the image's energy (using a sobel gradient as the base energy
 239      ** function) */
 240     /* Set the first energy line to 0 */
 241     memset( p_energy, 0, i_src_pitch*sizeof(int));
 242
 243     int *p_energy_prev = p_energy;
 244     for( y = 1; y < i_num_lines - 1;
 245          y++, p_energy_prev = p_energy, p_energy += i_src_pitch,
 246          p_grad += i_src_pitch )
 247     {
 248         /* Compute line y's minimum energy value for paths ending on
 249          * each x */
 250         x = 1;
 251         p_energy[x] = my_min( p_energy_prev[x  ]+p_grad[x  ],
 252                            p_energy_prev[x+1]+p_grad[x+1] );
 253         for( x = 2; x < i_src_visible - 2; x++ )
 254         {
 255             p_energy[x] = my_min3( p_energy_prev[x-1]+p_grad[x-1],
 256                                 p_energy_prev[x  ]+p_grad[x  ],
 257                                 p_energy_prev[x+1]+p_grad[x+1] );
 258         }
 259         p_energy[x] = my_min( p_energy_prev[x-1]+p_grad[x-1],
 260                            p_energy_prev[x  ]+p_grad[x  ] );
 261
 262 #ifdef DRAW_ENERGY
 263         int max = p_energy[1];
 264         for( x = 1; x < i_src_visible - 1; x++ )
 265             if( p_energy[x] > max ) max = p_energy[x];
 266         for( x = 1; x < i_src_visible - 1; x++ )
 267             p_outpix[y*i_src_pitch+x] = p_energy[x]*0xff/max;
 268 #endif
 269     }
 270
 271     /* Find the minimum energy point on the last line */
 272     y--;
 273     p_energy -= i_src_pitch;
 274     p_grad -= i_src_pitch;
 275
 276     int m = p_energy[1];
 277     int xmin = 1;
 278     for( x = 1; x < i_src_visible - 1; x++ )
 279     {
 280         if( p_energy[x] < m )
 281         {
 282             m = p_energy[x];
 283             xmin = x;
 284         }
 285     }
 286
 287 #ifdef DRAW_SEAM
 288     p_outpix[y*i_src_pitch+xmin] = 0xff;
 289     p_outpix[(y+1)*i_src_pitch+xmin] = 0xff;
 290 #else
 291     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 292     memmove( p_outpix+(y+1)*i_src_pitch+xmin, p_outpix+(y+1)*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 293 #endif
 294
 295     p_energy -= i_src_pitch;
 296     for( ; y>1; y--, p_energy -= i_src_pitch, p_grad -= i_src_pitch )
 297     {
 298         if( m != p_energy[xmin]+p_grad[xmin] )
 299         {
 300             if( xmin > 1 && m == p_energy[xmin-1]+p_grad[xmin-1] )
 301             {
 302                 xmin--;
 303             }
 304             else if( xmin < i_src_visible - 2 && m == p_energy[xmin+1]+p_grad[xmin+1] )
 305             {
 306                 xmin++;
 307             }
 308             else
 309             {
 310                 printf("Alarm! %d\n" ,y);
 311                 //assert( 0 );
 312             }
 313         }
 314         m = p_energy[xmin];
 315 #ifdef DRAW_SEAM
 316         p_outpix[y*i_src_pitch+xmin] = 0xff;
 317 #else
 318         memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 319 #endif
 320     }
 321 #ifdef DRAW_SEAM
 322     p_outpix[y*i_src_pitch+xmin] = 0xff;
 323 #else
 324     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 325 #endif
 326     y--;
 327 #ifdef DRAW_SEAM
 328     p_outpix[y*i_src_pitch+xmin] = 0xff;
 329 #else
 330     memmove( p_outpix+y*i_src_pitch+xmin, p_outpix+y*i_src_pitch+xmin+1, i_src_pitch-(xmin+1) );
 331 #endif
 332
 333 #if defined( DRAW_SEAM )
 334     return i_src_visible;
 335 #else
 336     return i_src_visible-1;
 337 #endif
 338 }
 339
 340 static inline int my_min3( int a, int b, int c )
 341 {
 342     if( a < b )
 343     {
 344         if( a < c ) return a;
 345         return c;
 346     }
 347     if( b < c ) return b;
 348     return c;
 349 }
 350 static inline int my_min( int a, int b )
 351 {
 352     return a < b ? a : b;
 353 }
 354
 355 static int CropCallback( vlc_object_t *p_this, char const *psz_var,
 356                                 vlc_value_t oldval, vlc_value_t newval,
 357                                 void *p_data )
 358 {
 359     VLC_UNUSED(p_this); VLC_UNUSED(psz_var); VLC_UNUSED(oldval);
 360     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 361     p_sys->i_crop = newval.i_int;
 362     return VLC_SUCCESS;
 363 }