summaryrefslogtreecommitdiff
path: root/ext/opencv/gsthanddetect.cpp
blob: 60fd5be72b127d022de7520a423517f010868984 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
/*
 * GStreamer hand gesture detection plugins
 * Copyright (C) 2012 Andol Li <<andol@andol.info>>
 * Copyright (C) 2013 Sreerenj Balachandran <sreerenj.balachandran@intel.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Alternatively, the contents of this file may be used under the
 * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
 * which case the following provisions apply instead of the ones
 * mentioned above:
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
/**
 * SECTION:video-filter-handdetect
 *
 * FIXME:operates hand gesture detection in video streams and images,
 * and enable media operation e.g. play/stop/fast forward/back rewind.
 *
 * <refsect2>
 * <title>Example launch line</title>
 * |[
 * gst-launch-1.0 autovideosrc ! videoconvert ! "video/x-raw, format=RGB, width=320, height=240" ! \
 * videoscale ! handdetect ! videoconvert ! xvimagesink
 * ]|
 * </refsect2>
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

/* element header */
#include "gsthanddetect.h"
#include <opencv2/imgproc/imgproc_c.h>

GST_DEBUG_CATEGORY_STATIC (gst_handdetect_debug);
#define GST_CAT_DEFAULT gst_handdetect_debug

/* define HAAR files */
#define HAAR_FILE_FIST GST_HAAR_CASCADES_DIR G_DIR_SEPARATOR_S "fist.xml"
#define HAAR_FILE_PALM GST_HAAR_CASCADES_DIR G_DIR_SEPARATOR_S "palm.xml"

using namespace cv;
using namespace std;
/* Filter signals and args */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

enum
{
  PROP_0,
  PROP_DISPLAY,
  PROP_PROFILE_FIST,
  PROP_PROFILE_PALM,
  PROP_ROI_X,
  PROP_ROI_Y,
  PROP_ROI_WIDTH,
  PROP_ROI_HEIGHT
};

/* the capabilities of the inputs and outputs */
static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("RGB"))
    );
static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("RGB"))
    );

static void gst_handdetect_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_handdetect_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static gboolean gst_handdetect_set_caps (GstOpencvVideoFilter * transform,
    gint in_width, gint in_height, gint in_depth, gint in_channels,
    gint out_width, gint out_height, gint out_depth, gint out_channels);
static GstFlowReturn gst_handdetect_transform_ip (GstOpencvVideoFilter *
    transform, GstBuffer * buffer, IplImage * img);

static CascadeClassifier *gst_handdetect_load_profile (GstHanddetect * filter,
    gchar * profile);

static void gst_handdetect_navigation_interface_init (GstNavigationInterface *
    iface);
static void gst_handdetect_navigation_send_event (GstNavigation * navigation,
    GstStructure * structure);

G_DEFINE_TYPE_WITH_CODE (GstHanddetect, gst_handdetect,
    GST_TYPE_OPENCV_VIDEO_FILTER,
    G_IMPLEMENT_INTERFACE (GST_TYPE_NAVIGATION,
        gst_handdetect_navigation_interface_init););

static void
gst_handdetect_navigation_interface_init (GstNavigationInterface * iface)
{
  iface->send_event = gst_handdetect_navigation_send_event;
}

/* FIXME: this function used to parse the region of interests coordinates
 * sending from applications when the hand gestures reach the defined regions of interests,
 * at this moment this function is not doing anything significantly
 * but will be CHANGED when the gstreamer is patched with new hand gesture events
 */
static void
gst_handdetect_navigation_send_event (GstNavigation * navigation,
    GstStructure * structure)
{
  GstHanddetect *filter = GST_HANDDETECT (navigation);
  GstPad *peer;

  if ((peer = gst_pad_get_peer (GST_BASE_TRANSFORM_CAST (filter)->sinkpad))) {
    GstEvent *event;
    event = gst_event_new_navigation (structure);
    gst_pad_send_event (peer, event);
    gst_object_unref (peer);
  }
}

/* clean opencv images and parameters */
static void
gst_handdetect_finalize (GObject * obj)
{
  GstHanddetect *filter = GST_HANDDETECT (obj);

  if (filter->cvGray)
    cvReleaseImage (&filter->cvGray);
  g_free (filter->profile_fist);
  g_free (filter->profile_palm);
  delete (filter->best_r);

  G_OBJECT_CLASS (gst_handdetect_parent_class)->finalize (obj);
}

/* initialise the HANDDETECT class */
static void
gst_handdetect_class_init (GstHanddetectClass * klass)
{
  GObjectClass *gobject_class;
  GstOpencvVideoFilterClass *gstopencvbasefilter_class;

  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
  gobject_class = (GObjectClass *) klass;
  gstopencvbasefilter_class = (GstOpencvVideoFilterClass *) klass;

  gstopencvbasefilter_class->cv_trans_ip_func = gst_handdetect_transform_ip;
  gstopencvbasefilter_class->cv_set_caps = gst_handdetect_set_caps;

  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_handdetect_finalize);
  gobject_class->set_property = gst_handdetect_set_property;
  gobject_class->get_property = gst_handdetect_get_property;

  g_object_class_install_property (gobject_class,
      PROP_DISPLAY,
      g_param_spec_boolean ("display",
          "Display",
          "Whether the detected hands are highlighted in output frame",
          TRUE, (GParamFlags)G_PARAM_READWRITE)
      );
  g_object_class_install_property (gobject_class,
      PROP_PROFILE_FIST,
      g_param_spec_string ("profile_fist",
          "Profile_fist",
          "Location of HAAR cascade file (fist gesture)",
          HAAR_FILE_FIST, (GParamFlags)G_PARAM_READWRITE)
      );
  g_object_class_install_property (gobject_class,
      PROP_PROFILE_PALM,
      g_param_spec_string ("profile_palm",
          "Profile_palm",
          "Location of HAAR cascade file (palm gesture)",
          HAAR_FILE_PALM, (GParamFlags)G_PARAM_READWRITE)
      );
  /* FIXME: property name needs fixing */
  g_object_class_install_property (gobject_class,
      PROP_ROI_X,
      g_param_spec_int ("ROI_X",
          "ROI_X",
          "X of left-top pointer in region of interest \nGestures in the defined region of interest will emit messages",
          0, INT_MAX, 0, (GParamFlags)G_PARAM_READWRITE)
      );
  /* FIXME: property name needs fixing */
  g_object_class_install_property (gobject_class,
      PROP_ROI_Y,
      g_param_spec_int ("ROI_Y",
          "ROI_Y",
          "Y of left-top pointer in region of interest \nGestures in the defined region of interest will emit messages",
          0, INT_MAX, 0, (GParamFlags)G_PARAM_READWRITE)
      );
  /* FIXME: property name needs fixing */
  g_object_class_install_property (gobject_class,
      PROP_ROI_WIDTH,
      g_param_spec_int ("ROI_WIDTH",
          "ROI_WIDTH",
          "WIDTH of left-top pointer in region of interest \nGestures in the defined region of interest will emit messages",
          0, INT_MAX, 0, (GParamFlags)G_PARAM_READWRITE)
      );
  /* FIXME: property name needs fixing */
  g_object_class_install_property (gobject_class,
      PROP_ROI_HEIGHT,
      g_param_spec_int ("ROI_HEIGHT",
          "ROI_HEIGHT",
          "HEIGHT of left-top pointer in region of interest \nGestures in the defined region of interest will emit messages",
          0, INT_MAX, 0, (GParamFlags)G_PARAM_READWRITE)
      );

  gst_element_class_set_static_metadata (element_class,
      "handdetect",
      "Filter/Effect/Video",
      "Performs hand gesture detection on videos, providing detected hand positions via bus message and navigation event, and deals with hand gesture events",
      "Andol Li <andol@andol.info>");

  gst_element_class_add_static_pad_template (element_class, &src_factory);
  gst_element_class_add_static_pad_template (element_class, &sink_factory);

}

/* initialise the new element
 * instantiate pads and add them to element
 * set pad call-back functions
 * initialise instance structure
 */
static void
gst_handdetect_init (GstHanddetect * filter)
{
  const gchar *haar_path;

  haar_path = g_getenv ("GST_HAAR_CASCADES_PATH");
  if (haar_path) {
    filter->profile_fist = g_build_filename (haar_path, "fist.xml", NULL);
    filter->profile_palm = g_build_filename (haar_path, "palm.xml", NULL);
  } else {
    filter->profile_fist = g_strdup (HAAR_FILE_FIST);
    filter->profile_palm = g_strdup (HAAR_FILE_PALM);
  }

  filter->roi_x = 0;
  filter->roi_y = 0;
  filter->roi_width = 0;
  filter->roi_height = 0;
  filter->display = TRUE;

  filter->cvCascade_fist =
      gst_handdetect_load_profile (filter, filter->profile_fist);
  filter->cvCascade_palm =
      gst_handdetect_load_profile (filter, filter->profile_palm);

  gst_opencv_video_filter_set_in_place (GST_OPENCV_VIDEO_FILTER_CAST (filter),
      TRUE);
}

static void
gst_handdetect_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstHanddetect *filter = GST_HANDDETECT (object);

  switch (prop_id) {
    case PROP_PROFILE_FIST:
      g_free (filter->profile_fist);
      if (filter->cvCascade_fist)
        delete filter->cvCascade_fist;
      filter->profile_fist = g_value_dup_string (value);
      filter->cvCascade_fist =
          gst_handdetect_load_profile (filter, filter->profile_fist);
      break;
    case PROP_PROFILE_PALM:
      g_free (filter->profile_palm);
      if (filter->cvCascade_palm)
        delete filter->cvCascade_palm;
      filter->profile_palm = g_value_dup_string (value);
      filter->cvCascade_palm =
          gst_handdetect_load_profile (filter, filter->profile_palm);
      break;
    case PROP_DISPLAY:
      filter->display = g_value_get_boolean (value);
      break;
    case PROP_ROI_X:
      filter->roi_x = g_value_get_int (value);
      break;
    case PROP_ROI_Y:
      filter->roi_y = g_value_get_int (value);
      break;
    case PROP_ROI_WIDTH:
      filter->roi_width = g_value_get_int (value);
      break;
    case PROP_ROI_HEIGHT:
      filter->roi_height = g_value_get_int (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_handdetect_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstHanddetect *filter = GST_HANDDETECT (object);

  switch (prop_id) {
    case PROP_DISPLAY:
      g_value_set_boolean (value, filter->display);
      break;
    case PROP_PROFILE_FIST:
      g_value_set_string (value, filter->profile_fist);
      break;
    case PROP_PROFILE_PALM:
      g_value_set_string (value, filter->profile_palm);
      break;
    case PROP_ROI_X:
      g_value_set_int (value, filter->roi_x);
      break;
    case PROP_ROI_Y:
      g_value_set_int (value, filter->roi_y);
      break;
    case PROP_ROI_WIDTH:
      g_value_set_int (value, filter->roi_width);
      break;
    case PROP_ROI_HEIGHT:
      g_value_set_int (value, filter->roi_height);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

/* GstElement vmethod implementations */
/* this function handles the link with other elements */
static gboolean
gst_handdetect_set_caps (GstOpencvVideoFilter * transform,
    gint in_width, gint in_height, gint in_depth, gint in_channels,
    gint out_width, gint out_height, gint out_depth, gint out_channels)
{
  GstHanddetect *filter;
  filter = GST_HANDDETECT (transform);

  /* 320 x 240 is with the best detect accuracy, if not, give info */
  if (in_width != 320 || in_height != 240)
    GST_WARNING_OBJECT (filter,
        "resize to 320 x 240 to have best detect accuracy.\n");

  if (filter->cvGray)
    cvReleaseImage (&filter->cvGray);
  filter->cvGray =
      cvCreateImage (cvSize (in_width, in_height), IPL_DEPTH_8U, 1);

  return TRUE;
}

/* Hand detection function
 * This function does the actual processing 'of hand detect and display'
 */
static GstFlowReturn
gst_handdetect_transform_ip (GstOpencvVideoFilter * transform,
    GstBuffer * buffer, IplImage * img)
{
  GstHanddetect *filter = GST_HANDDETECT (transform);
  Rect *r;
  GstStructure *s;
  GstMessage *m;
  unsigned int i;
  vector < Rect > hands;

  /* check detection cascades */
  if (filter->cvCascade_fist && filter->cvCascade_palm) {
  /* cvt to gray colour space for hand detect */
    cvCvtColor (img, filter->cvGray, CV_RGB2GRAY);

    /* detect FIST gesture fist */
    Mat image = cvarrToMat(filter->cvGray);
    Mat roi (image, Rect (filter->cvGray->origin,
            filter->cvGray->origin, filter->cvGray->width,
            filter->cvGray->height));
    filter->cvCascade_fist->detectMultiScale (roi, hands, 1.1, 2,
        CV_HAAR_DO_CANNY_PRUNING, cvSize (24, 24), cvSize (0, 0));

    /* if FIST gesture detected */
    if (!hands.empty ()) {

      int min_distance, distance;
      Rect temp_r;
      CvPoint c;

      /* Go through all detected FIST gestures to get the best one
       * prev_r => previous hand
       * best_r => best hand in this frame
       */
      /* set min_distance for init comparison */
      min_distance = img->width + img->height;
      /* Init filter->prev_r */
      temp_r = Rect (0, 0, 0, 0);
      if (filter->prev_r == NULL)
        filter->prev_r = &temp_r;
      /* Get the best FIST gesture */
      for (i = 0; i < hands.size(); i++) {
        r = &hands[i];
        distance = (int) sqrt (pow ((r->x - filter->prev_r->x),
                2) + pow ((r->y - filter->prev_r->y), 2));
        if (distance <= min_distance) {
          min_distance = distance;
          delete (filter->best_r);
          filter->best_r = new Rect (*r);
        }
      }
      /* Save best_r as prev_r for next frame comparison */
      filter->prev_r = filter->best_r;

      /* send msg to app/bus if the detected gesture falls in the region of interest */
      /* get center point of gesture */
      c = cvPoint (filter->best_r->x + filter->best_r->width / 2,
          filter->best_r->y + filter->best_r->height / 2);
      /* send message:
       * if the center point is in the region of interest, OR,
       * if the region of interest remains default as (0,0,0,0)*/
      if ((c.x >= filter->roi_x && c.x <= (filter->roi_x + filter->roi_width)
              && c.y >= filter->roi_y
              && c.y <= (filter->roi_y + filter->roi_height))
          || (filter->roi_x == 0
              && filter->roi_y == 0
              && filter->roi_width == 0 && filter->roi_height == 0)) {
        /* Define structure for message post */
        s = gst_structure_new ("hand-gesture",
            "gesture", G_TYPE_STRING, "fist",
            "x", G_TYPE_INT,
            (gint) (filter->best_r->x + filter->best_r->width * 0.5), "y",
            G_TYPE_INT,
            (gint) (filter->best_r->y + filter->best_r->height * 0.5), "width",
            G_TYPE_INT, (gint) filter->best_r->width, "height", G_TYPE_INT,
            (gint) filter->best_r->height, NULL);
        /* Init message element */
        m = gst_message_new_element (GST_OBJECT (filter), s);
        /* Send message */
        gst_element_post_message (GST_ELEMENT (filter), m);

#if 0
        /* send event
         * here we use mouse-move event instead of fist-move or palm-move event
         * !!! this will CHANGE in the future !!!
         * !!! by adding gst_navigation_send_hand_detect_event() in navigation.c !!!
         */
        gst_navigation_send_mouse_event (GST_NAVIGATION (filter),
            "mouse-move",
            0,
            (double) (filter->best_r->x + filter->best_r->width * 0.5),
            (double) (filter->best_r->y + filter->best_r->height * 0.5));

#endif
      }
      /* Check filter->display,
       * If TRUE, displaying red circle marker in the out frame */
      if (filter->display) {
        CvPoint center;
        int radius;
        center.x = cvRound ((filter->best_r->x + filter->best_r->width * 0.5));
        center.y = cvRound ((filter->best_r->y + filter->best_r->height * 0.5));
        radius =
            cvRound ((filter->best_r->width + filter->best_r->height) * 0.25);
        cvCircle (img, center, radius, CV_RGB (0, 0, 200), 1, 8, 0);
      }
    } else {
     /* if NO FIST gesture, detecting PALM gesture */
      filter->cvCascade_palm->detectMultiScale (roi, hands, 1.1, 2,
          CV_HAAR_DO_CANNY_PRUNING, cvSize (24, 24), cvSize (0, 0));
      /* if PALM detected */
      if (!hands.empty ()) {
        int min_distance, distance;
        Rect temp_r;
        CvPoint c;

        if (filter->display) {
          GST_DEBUG_OBJECT (filter, "%d PALM gestures detected\n",
              (int) hands.size ());
        }
        /* Go through all detected PALM gestures to get the best one
         * prev_r => previous hand
         * best_r => best hand in this frame
         */
        /* suppose a min_distance for init comparison */
        min_distance = img->width + img->height;
        /* Init filter->prev_r */
        temp_r = Rect (0, 0, 0, 0);
       if (filter->prev_r == NULL)
          filter->prev_r = &temp_r;
        /* Get the best PALM gesture */
        for (i = 0; i < hands.size (); ++i) {
          r = &hands[i];
          distance = (int) sqrt (pow ((r->x - filter->prev_r->x),
                  2) + pow ((r->y - filter->prev_r->y), 2));
          if (distance <= min_distance) {
            min_distance = distance;
            delete (filter->best_r);
            filter->best_r = new Rect (*r);
          }
        }
        /* Save best_r as prev_r for next frame comparison */
        filter->prev_r = filter->best_r;

        /* send msg to app/bus if the detected gesture falls in the region of interest */
        /* get center point of gesture */
        c = cvPoint (filter->best_r->x + filter->best_r->width / 2,
            filter->best_r->y + filter->best_r->height / 2);
        /* send message:
         * if the center point is in the region of interest, OR,
         * if the region of interest remains default as (0,0,0,0)*/
        if (((gint) c.x >= filter->roi_x
                && (gint) c.x <= (filter->roi_x + filter->roi_width)
                && (gint) c.y >= filter->roi_y
                && (gint) c.y <= (filter->roi_y + filter->roi_height))
            || (filter->roi_x == 0 && filter->roi_y == 0
                && filter->roi_width == 0 && filter->roi_height == 0)) {
          /* Define structure for message post */
          s = gst_structure_new ("hand-gesture",
              "gesture", G_TYPE_STRING, "palm",
              "x", G_TYPE_INT,
              (gint) (filter->best_r->x + filter->best_r->width * 0.5), "y",
              G_TYPE_INT,
              (gint) (filter->best_r->y + filter->best_r->height * 0.5),
              "width", G_TYPE_INT, (gint) filter->best_r->width, "height",
              G_TYPE_INT, (gint) filter->best_r->height, NULL);
          /* Init message element */
          m = gst_message_new_element (GST_OBJECT (filter), s);
          /* Send message */
          gst_element_post_message (GST_ELEMENT (filter), m);

#if 0
          /* send event
           * here we use mouse-move event instead of fist-move or palm-move event
           * !!! this will CHANGE in the future !!!
           * !!! by adding gst_navigation_send_hand_detect_event() in navigation.c !!!
           */
          gst_navigation_send_mouse_event (GST_NAVIGATION (filter),
              "mouse-move",
              0,
              (double) (filter->best_r->x + filter->best_r->width * 0.5),
              (double) (filter->best_r->y + filter->best_r->height * 0.5));

          /* or use another way to send upstream navigation event for debug
           *
           * GstEvent *event =
           * gst_event_new_navigation (gst_structure_new
           * ("application/x-gst-navigation", "event", G_TYPE_STRING,
           * "mouse-move",
           * "button", G_TYPE_INT, 0,
           * "pointer_x", G_TYPE_DOUBLE,
           * (double) (filter->best_r->x + filter->best_r->width * 0.5),
           * "pointer_y", G_TYPE_DOUBLE,
           * (double) (filter->best_r->y + filter->best_r->height * 0.5),
           * NULL));
           * gst_pad_send_event (GST_BASE_TRANSFORM_CAST (filter)->srcpad, event);
           */
#endif
        }
        /* Check filter->display,
         * If TRUE, displaying red circle marker in the out frame */
        if (filter->display) {
          CvPoint center;
          int radius;
          center.x =
              cvRound ((filter->best_r->x + filter->best_r->width * 0.5));
          center.y =
              cvRound ((filter->best_r->y + filter->best_r->height * 0.5));
          radius =
              cvRound ((filter->best_r->width + filter->best_r->height) * 0.25);
          cvCircle (img, center, radius, CV_RGB (0, 0, 200), 1, 8, 0);
        }
      }
    }
  }

  /* Push out the incoming buffer */
  return GST_FLOW_OK;
}

static CascadeClassifier *
gst_handdetect_load_profile (GstHanddetect * filter, gchar * profile)
{
  CascadeClassifier *cascade;

  cascade = new CascadeClassifier (profile);
  if (cascade->empty ()) {
    GST_ERROR_OBJECT (filter, "Invalid profile file: %s", profile);
    delete cascade;
    return NULL;
  }

  return cascade;
}

/* Entry point to initialize the plug-in
 * Initialize the plug-in itself
 * Register the element factories and other features
 */
gboolean
gst_handdetect_plugin_init (GstPlugin * plugin)
{
  GST_DEBUG_CATEGORY_INIT (gst_handdetect_debug,
      "handdetect", 0, "opencv hand gesture detection");
  return gst_element_register (plugin, "handdetect", GST_RANK_NONE,
      GST_TYPE_HANDDETECT);
}