floodfill.c

   1 /* Copyright (C) <2010> Douglas Bagnall <douglas@halo.gen.nz>
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Library General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Library General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Library General Public
  14  * License along with this library; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 02111-1307, USA.
  17  */
  18
  19 #include "sparrow.h"
  20 #include "gstsparrow.h"
  21
  22 #include <string.h>
  23 #include <math.h>
  24
  25 #define STUPID_DEBUG_TRICK 0
  26 #define WAIT_TIME CALIBRATE_MAX_T + 5
  27
  28 typedef struct sparrow_find_screen_s {
  29   IplImage *green;
  30   IplImage *working;
  31   IplImage *mask;
  32   IplImage *im;
  33   gboolean waiting;
  34   IplImage *signal;
  35 } sparrow_find_screen_t;
  36
  37
  38 /* Floodfill for find screen */
  39 static inline void
  40 expand_one_mono(int x, int y, int c,
  41     CvPoint *nexts, int *n_nexts, guint8 *im, guint8 *mask, int w, int h){
  42   guint8 p = im[y * w + x];
  43   guint8 *m = &mask[y * w + x];
  44   if (*m && (p == c)){
  45     *m = 0;
  46     nexts[*n_nexts].x = x;
  47     nexts[*n_nexts].y = y;
  48     (*n_nexts)++;
  49   }
  50 }
  51
  52 /*
  53   im: the image to be analysed
  54   mim: the mask image to be written
  55   start: a point of the right colour.
  56 */
  57
  58 static IplImage*
  59 floodfill_mono_superfast(IplImage *im, IplImage *mim, CvPoint start)
  60 {
  61   guint8 * data = (guint8 *)im->imageData;
  62   guint8 * mdata = (guint8 *)mim->imageData;
  63   int w = im->width;
  64   int h = im->height;
  65   int n_starts;
  66   int n_nexts = 0;
  67   CvPoint *starts;
  68   CvPoint *nexts;
  69
  70   //malloc 2 lists of points. These *could* be as large as the image (but never should be)
  71   void * mem = malloc_or_die(w * h * 2 * sizeof(CvPoint));
  72   starts = mem;
  73   nexts = starts + w * h;
  74   n_starts = 1;
  75   starts[0] = start;
  76
  77   while(n_starts){
  78     n_nexts = 0;
  79     int i;
  80     for (i = 0; i < n_starts; i++){
  81       int x = starts[i].x;
  82       int y = starts[i].y;
  83       int c = data[y * w + x];
  84       if (x > 0){
  85         expand_one_mono(x - 1, y, c, nexts, &n_nexts, data, mdata, w, h);
  86       }
  87       if (x < w - 1){
  88         expand_one_mono(x + 1, y, c, nexts, &n_nexts, data, mdata, w, h);
  89       }
  90       if (y > 0){
  91         expand_one_mono(x, y - 1, c, nexts, &n_nexts, data, mdata, w, h);
  92       }
  93       if (y < h - 1){
  94         expand_one_mono(x, y + 1, c, nexts, &n_nexts, data, mdata, w, h);
  95       }
  96     }
  97     CvPoint *tmp = starts;
  98     starts = nexts;
  99     nexts = tmp;
 100     n_starts = n_nexts;
 101   }
 102   free(mem);
 103   return im;
 104 }
 105
 106 static inline IplImage *
 107 extract_green_channel(GstSparrow *sparrow,  sparrow_find_screen_t *finder, guint8 *in)
 108 {
 109   IplImage *im = finder->im;
 110   IplImage *green = finder->green;
 111   im->imageData = (char*)in;
 112   guint32 gshift = sparrow->in.gshift;
 113   cvSplit(im,
 114       (gshift == 24) ? green : NULL,
 115       (gshift == 16) ? green : NULL,
 116       (gshift ==  8) ? green : NULL,
 117       (gshift ==  0) ? green : NULL);
 118   return green;
 119 }
 120
 121
 122 #define SIGNAL_THRESHOLD 100
 123 /*see whether there seems to be activity:  */
 124 gboolean INVISIBLE
 125 check_for_signal(GstSparrow *sparrow, sparrow_find_screen_t *finder, guint8 *in){
 126   IplImage *green = extract_green_channel(sparrow, finder, in);
 127   IplImage *working = finder->working;
 128   guint i;
 129   gboolean answer = FALSE;
 130   cvAbsDiff(green, finder->working, finder->signal);
 131   for (i = 0; i < sparrow->in.pixcount; i++){
 132     if (finder->signal->imageData[i] > SIGNAL_THRESHOLD){
 133       answer = TRUE;
 134       break;
 135     }
 136   }
 137   //memcpy(finder->working, green, sparrow->in.pixcount);
 138   char *tmp = working->imageData;
 139   working->imageData = green->imageData;
 140   green->imageData = tmp;
 141   return answer;
 142 }
 143
 144
 145 /* a minature state progression within this one, in case the processing is too
 146    much for one frame.*/
 147 INVISIBLE sparrow_state
 148 mode_find_screen(GstSparrow *sparrow, guint8 *in, guint8 *out){
 149   sparrow->countdown--;
 150   GST_DEBUG("in find_screen with countdown %d\n", sparrow->countdown);
 151   sparrow_find_screen_t *finder = (sparrow_find_screen_t *)sparrow->helper_struct;
 152   IplImage *green;
 153   IplImage *working = finder->working;
 154   IplImage *mask = finder->mask;
 155   /* size is 1 byte per pixel, not 4! */
 156   size_t size = sparrow->in.pixcount;
 157   CvPoint middle, corner;
 158   switch (sparrow->countdown){
 159   case 6:
 160   case 5:
 161   case 4:
 162   case 3:
 163     /*send white and wait for the picture to arrive back. */
 164     goto white;
 165   case 2:
 166     /* time to look and see if the screen is there.
 167        Look at the histogram of a single channel. */
 168     green = extract_green_channel(sparrow, finder, in);
 169     cvCanny(green, mask, 100, 170, 3);
 170     MAYBE_DEBUG_IPL(mask);
 171     goto black;
 172   case 1:
 173     /* floodfill where the screen is, removing outlying bright spots*/
 174     middle = (CvPoint){sparrow->in.width / 2, sparrow->in.height / 2};
 175     memset(working->imageData, 255, size);
 176     floodfill_mono_superfast(mask, working, middle);
 177     MAYBE_DEBUG_IPL(working);
 178     goto black;
 179   case 0:
 180     /* floodfill the border, removing onscreen dirt.*/
 181     corner = (CvPoint){0, 0};
 182     memset(mask->imageData, 255, size);
 183     floodfill_mono_superfast(working, mask, corner);
 184 #if STUPID_DEBUG_TRICK
 185     cvErode(mask, mask, NULL, 9);
 186 #endif
 187     MAYBE_DEBUG_IPL(mask);
 188     goto finish;
 189   default:
 190     GST_DEBUG("checking for signal. sparrow countdown is %d", sparrow->countdown);
 191     if (check_for_signal(sparrow, finder, in)){
 192       sparrow->countdown = sparrow->lag + WAIT_TIME;
 193     }
 194     goto black;
 195   }
 196  white:
 197   memset(out, 255, sparrow->out.size);
 198   return SPARROW_STATUS_QUO;
 199  black:
 200   memset(out, 0, sparrow->out.size);
 201   return SPARROW_STATUS_QUO;
 202  finish:
 203   memset(out, 0, sparrow->out.size);
 204   return SPARROW_NEXT_STATE;
 205 }
 206
 207 INVISIBLE void
 208 finalise_find_screen(GstSparrow *sparrow){
 209   sparrow_find_screen_t *finder = (sparrow_find_screen_t *)sparrow->helper_struct;
 210   GST_DEBUG("finalise_find_screen: green %p, working %p, mask %p, im %p finder %p\n",
 211       finder->green, finder->working, finder->mask, finder->im, finder);
 212   cvReleaseImage(&finder->signal);
 213   cvReleaseImage(&finder->green);
 214   cvReleaseImage(&finder->working);
 215   cvReleaseImageHeader(&finder->mask);
 216   cvReleaseImageHeader(&finder->im);
 217   free(finder);
 218 }
 219
 220 INVISIBLE void
 221 init_find_screen(GstSparrow *sparrow){
 222   sparrow_find_screen_t *finder = zalloc_aligned_or_die(sizeof(sparrow_find_screen_t));
 223   sparrow->helper_struct = (void *)finder;
 224   sparrow->countdown = sparrow->lag + WAIT_TIME;
 225   finder->waiting = TRUE;
 226   CvSize size = {sparrow->in.width, sparrow->in.height};
 227   finder->green = cvCreateImage(size, IPL_DEPTH_8U, 1);
 228   finder->working = cvCreateImage(size, IPL_DEPTH_8U, 1);
 229   finder->signal = cvCreateImage(size, IPL_DEPTH_8U, 1);
 230   finder->im = init_ipl_image(&sparrow->in, PIXSIZE);
 231   finder->mask  = init_ipl_image(&sparrow->in, 1);
 232
 233   finder->mask->imageData = (char *)sparrow->screenmask;
 234   GST_DEBUG("init_find_screen: green %p, working %p, mask %p, im %p finder %p\n",
 235       finder->green, finder->working, finder->mask, finder->im, finder);
 236 }
 237