ext/opencv/gstskindetect.cpp - imx-gst-plugins-bad - Git at Google

 /*
  * GStreamer
  * Copyright (C) 2013 Miguel Casas-Sanchez <miguelecasassanchez@gmail.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., 51 Franklin St, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */

 /**
  * SECTION:element-skindetect
  *
  * Human skin detection on videos and images
  *
  * <refsect2>
  * <title>Example launch line</title>
  * |[
  * gst-launch-1.0 videotestsrc ! decodebin ! videoconvert ! skindetect ! videoconvert ! xvimagesink
  * ]|
  * </refsect2>
  */

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

 #include "gstskindetect.h"
 #include <opencv2/imgproc/imgproc_c.h>

 GST_DEBUG_CATEGORY_STATIC (gst_skin_detect_debug);
 #define GST_CAT_DEFAULT gst_skin_detect_debug

 /* Filter signals and args */
 enum
 {
   /* FILL ME */
   LAST_SIGNAL
 };

 enum
 {
   PROP_0,
   PROP_POSTPROCESS,
   PROP_METHOD,
   PROP_MASK
 };
 typedef enum
 {
   HSV,
   RGB
 } GstSkindetectMethod;

 #define GST_TYPE_SKIN_DETECT_METHOD (gst_skin_detect_method_get_type ())
 static GType
 gst_skin_detect_method_get_type (void)
 {
   static GType etype = 0;
   if (etype == 0) {
     static const GEnumValue values[] = {
       {HSV, "Classic HSV thresholding", "hsv"},
       {RGB, "Normalised-RGB colorspace thresholding", "rgb"},
       {0, NULL, NULL},
     };
     etype = g_enum_register_static ("GstSkindetectMethod", values);
   }
   return etype;
 }

 G_DEFINE_TYPE (GstSkinDetect, gst_skin_detect, GST_TYPE_OPENCV_VIDEO_FILTER);
 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_skin_detect_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec);
 static void gst_skin_detect_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec);

 static GstFlowReturn gst_skin_detect_transform (GstOpencvVideoFilter * filter,
     GstBuffer * buf, IplImage * img, GstBuffer * outbuf, IplImage * outimg);

 static gboolean gst_skin_detect_stop (GstBaseTransform * basesrc);
 static gboolean
 gst_skin_detect_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 void gst_skin_detect_release_all_images (GstSkinDetect * filter);

 /* initialize the skindetect's class */
 static void
 gst_skin_detect_class_init (GstSkinDetectClass * klass)
 {
   GObjectClass *gobject_class;
   GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
   GstBaseTransformClass *basesrc_class = GST_BASE_TRANSFORM_CLASS (klass);
   GstOpencvVideoFilterClass *gstopencvbasefilter_class;

   gobject_class = (GObjectClass *) klass;
   gstopencvbasefilter_class = (GstOpencvVideoFilterClass *) klass;

   gobject_class->set_property = gst_skin_detect_set_property;
   gobject_class->get_property = gst_skin_detect_get_property;

   gstopencvbasefilter_class->cv_trans_func = gst_skin_detect_transform;

   g_object_class_install_property (gobject_class, PROP_POSTPROCESS,
       g_param_spec_boolean ("postprocess", "Postprocess",
           "Apply opening-closing to skin detection to extract large, significant blobs ",
           TRUE, (GParamFlags)
           (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
   g_object_class_install_property (gobject_class, PROP_METHOD,
       g_param_spec_enum ("method",
           "Method to use",
           "Method to use",
           GST_TYPE_SKIN_DETECT_METHOD, HSV,
           (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));

   gst_element_class_set_static_metadata (element_class,
       "skindetect",
       "Filter/Effect/Video",
       "Performs non-parametric skin detection on input",
       "Miguel Casas-Sanchez <miguelecasassanchez@gmail.com>");

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

   basesrc_class->stop = gst_skin_detect_stop;
   gstopencvbasefilter_class->cv_set_caps = gst_skin_detect_set_caps;
 }

 /* initialize the new element
  * instantiate pads and add them to element
  * set pad calback functions
  * initialize instance structure
  */
 static void
 gst_skin_detect_init (GstSkinDetect * filter)
 {
   filter->postprocess = TRUE;
   filter->method = HSV;

   gst_opencv_video_filter_set_in_place (GST_OPENCV_VIDEO_FILTER_CAST (filter),
       FALSE);
 }


 static void
 gst_skin_detect_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec)
 {
   GstSkinDetect *filter = GST_SKIN_DETECT (object);

   switch (prop_id) {
     case PROP_POSTPROCESS:
       filter->postprocess = g_value_get_boolean (value);
       break;
     case PROP_METHOD:
       filter->method = g_value_get_enum (value);
       break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
   }
 }

 static void
 gst_skin_detect_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec)
 {
   GstSkinDetect *filter = GST_SKIN_DETECT (object);

   switch (prop_id) {
     case PROP_POSTPROCESS:
       g_value_set_boolean (value, filter->postprocess);
       break;
     case PROP_METHOD:
       g_value_set_enum (value, filter->method);
       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_skin_detect_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)
 {
   GstSkinDetect *filter = GST_SKIN_DETECT (transform);
   CvSize size = cvSize (in_width, in_height);

   // If cvRGB is already allocated, it means there's a cap modification,
   // so release first all the images.
   if (NULL != filter->cvRGB)
     gst_skin_detect_release_all_images (filter);


   filter->cvRGB = cvCreateImageHeader (size, IPL_DEPTH_8U, 3);
   filter->cvSkin = cvCreateImageHeader (size, IPL_DEPTH_8U, 3);
   filter->cvChA = cvCreateImage (size, IPL_DEPTH_8U, 1);
   filter->width = in_width;
   filter->height = in_height;

   filter->cvHSV = cvCreateImage (size, IPL_DEPTH_8U, 3);
   filter->cvH = cvCreateImage (size, 8, 1);     /*  Hue component. */
   filter->cvH2 = cvCreateImage (size, 8, 1);    /*  Hue component, 2nd threshold */
   filter->cvS = cvCreateImage (size, 8, 1);     /*  Saturation component. */
   filter->cvV = cvCreateImage (size, 8, 1);     /*  Brightness component. */
   filter->cvSkinPixels1 = cvCreateImage (size, 8, 1);   /*  Greyscale output image */

   filter->cvR = cvCreateImage (size, 8, 1);     /*  R component. */
   filter->cvG = cvCreateImage (size, 8, 1);     /*  G component. */
   filter->cvB = cvCreateImage (size, 8, 1);     /*  B component. */
   filter->cvAll = cvCreateImage (size, IPL_DEPTH_32F, 1);       /*  (R+G+B) component. */
   filter->cvR2 = cvCreateImage (size, IPL_DEPTH_32F, 1);        /*  R component, 32bits */
   filter->cvRp = cvCreateImage (size, IPL_DEPTH_32F, 1);        /*  R' and >0.4 */
   filter->cvGp = cvCreateImage (size, IPL_DEPTH_32F, 1);        /*  G' and > 0.28 */
   filter->cvRp2 = cvCreateImage (size, IPL_DEPTH_32F, 1);       /*  R' <0.6 */
   filter->cvGp2 = cvCreateImage (size, IPL_DEPTH_32F, 1);       /*  G' <0.4 */
   filter->cvSkinPixels2 = cvCreateImage (size, IPL_DEPTH_32F, 1);       /*  Greyscale output image. */
   filter->cvdraft = cvCreateImage (size, IPL_DEPTH_8U, 1);      /*  Greyscale output image. */

   return TRUE;
 }

 /* Clean up */
 static gboolean
 gst_skin_detect_stop (GstBaseTransform * basesrc)
 {
   GstSkinDetect *filter = GST_SKIN_DETECT (basesrc);

   if (filter->cvRGB != NULL)
     gst_skin_detect_release_all_images (filter);
   return TRUE;
 }

 static void
 gst_skin_detect_release_all_images (GstSkinDetect * filter)
 {
   cvReleaseImage (&filter->cvRGB);
   cvReleaseImage (&filter->cvSkin);
   cvReleaseImage (&filter->cvChA);

   cvReleaseImage (&filter->cvHSV);
   cvReleaseImage (&filter->cvH);
   cvReleaseImage (&filter->cvH2);
   cvReleaseImage (&filter->cvS);
   cvReleaseImage (&filter->cvV);
   cvReleaseImage (&filter->cvSkinPixels1);

   cvReleaseImage (&filter->cvR);
   cvReleaseImage (&filter->cvG);
   cvReleaseImage (&filter->cvB);
   cvReleaseImage (&filter->cvAll);
   cvReleaseImage (&filter->cvR2);
   cvReleaseImage (&filter->cvRp);
   cvReleaseImage (&filter->cvGp);
   cvReleaseImage (&filter->cvRp2);
   cvReleaseImage (&filter->cvGp2);
   cvReleaseImage (&filter->cvSkinPixels2);
   cvReleaseImage (&filter->cvdraft);
 }

 static GstFlowReturn
 gst_skin_detect_transform (GstOpencvVideoFilter * base, GstBuffer * buf,
     IplImage * img, GstBuffer * outbuf, IplImage * outimg)
 {
   GstSkinDetect *filter = GST_SKIN_DETECT (base);

   filter->cvRGB->imageData = (char *) img->imageData;
   filter->cvSkin->imageData = (char *) outimg->imageData;

   /* SKIN COLOUR BLOB DETECTION */
   if (HSV == filter->method) {
     cvCvtColor (filter->cvRGB, filter->cvHSV, CV_RGB2HSV);
     cvSplit (filter->cvHSV, filter->cvH, filter->cvS, filter->cvV, 0);  /*  Extract the 3 color components. */

     /*  Detect which pixels in each of the H, S and V channels are probably skin pixels.
        Assume that skin has a Hue between 0 to 18 (out of 180), and Saturation above 50, and Brightness above 80. */
     cvThreshold (filter->cvH, filter->cvH2, 10, UCHAR_MAX, CV_THRESH_BINARY);   /* (hue > 10) */
     cvThreshold (filter->cvH, filter->cvH, 20, UCHAR_MAX, CV_THRESH_BINARY_INV);        /* (hue < 20) */
     cvThreshold (filter->cvS, filter->cvS, 48, UCHAR_MAX, CV_THRESH_BINARY);    /* (sat > 48) */
     cvThreshold (filter->cvV, filter->cvV, 80, UCHAR_MAX, CV_THRESH_BINARY);    /* (val > 80) */

     /*  erode the HUE to get rid of noise. */
     cvErode (filter->cvH, filter->cvH, NULL, 1);

     /*  Combine all 3 thresholded color components, so that an output pixel will only
        be white (255) if the H, S and V pixels were also white.
        imageSkin = (hue > 10) ^ (hue < 20) ^ (sat > 48) ^ (val > 80), where   ^ mean pixels-wise AND */
     cvAnd (filter->cvH, filter->cvS, filter->cvSkinPixels1, NULL);
     cvAnd (filter->cvSkinPixels1, filter->cvH2, filter->cvSkinPixels1, NULL);
     cvAnd (filter->cvSkinPixels1, filter->cvV, filter->cvSkinPixels1, NULL);

     cvCvtColor (filter->cvSkinPixels1, filter->cvRGB, CV_GRAY2RGB);
   } else if (RGB == filter->method) {
     cvSplit (filter->cvRGB, filter->cvR, filter->cvG, filter->cvB, 0);  /*  Extract the 3 color components. */
     cvAdd (filter->cvR, filter->cvG, filter->cvAll, NULL);
     cvAdd (filter->cvB, filter->cvAll, filter->cvAll, NULL);    /*  All = R + G + B */
     cvDiv (filter->cvR, filter->cvAll, filter->cvRp, 1.0);      /*  R' = R / ( R + G + B) */
     cvDiv (filter->cvG, filter->cvAll, filter->cvGp, 1.0);      /*  G' = G / ( R + G + B) */

     cvConvertScale (filter->cvR, filter->cvR2, 1.0, 0.0);
     cvCopy (filter->cvGp, filter->cvGp2, NULL);
     cvCopy (filter->cvRp, filter->cvRp2, NULL);

     cvThreshold (filter->cvR2, filter->cvR2, 60, UCHAR_MAX, CV_THRESH_BINARY);  /* (R > 60) */
     cvThreshold (filter->cvRp, filter->cvRp, 0.42, UCHAR_MAX, CV_THRESH_BINARY);        /* (R'> 0.4) */
     cvThreshold (filter->cvRp2, filter->cvRp2, 0.6, UCHAR_MAX, CV_THRESH_BINARY_INV);   /* (R'< 0.6) */
     cvThreshold (filter->cvGp, filter->cvGp, 0.28, UCHAR_MAX, CV_THRESH_BINARY);        /* (G'> 0.28) */
     cvThreshold (filter->cvGp2, filter->cvGp2, 0.4, UCHAR_MAX, CV_THRESH_BINARY_INV);   /* (G'< 0.4) */

     /*  Combine all 3 thresholded color components, so that an output pixel will only
        be white (255) if the H, S and V pixels were also white. */

     cvAnd (filter->cvR2, filter->cvRp, filter->cvSkinPixels2, NULL);
     cvAnd (filter->cvRp, filter->cvSkinPixels2, filter->cvSkinPixels2, NULL);
     cvAnd (filter->cvRp2, filter->cvSkinPixels2, filter->cvSkinPixels2, NULL);
     cvAnd (filter->cvGp, filter->cvSkinPixels2, filter->cvSkinPixels2, NULL);
     cvAnd (filter->cvGp2, filter->cvSkinPixels2, filter->cvSkinPixels2, NULL);

     cvConvertScale (filter->cvSkinPixels2, filter->cvdraft, 1.0, 0.0);
     cvCvtColor (filter->cvdraft, filter->cvRGB, CV_GRAY2RGB);
   }

   /* After this we have a RGB Black and white image with the skin, in
      filter->cvRGB. We can postprocess by applying 1 erode-dilate and 1
      dilate-erode, or alternatively 1 opening-closing all together, with
      the goal of removing small (spurious) skin spots and creating large
      connected areas */
   if (filter->postprocess) {
     cvSplit (filter->cvRGB, filter->cvChA, NULL, NULL, NULL);

     cvErode (filter->cvChA, filter->cvChA,
         cvCreateStructuringElementEx (3, 3, 1, 1, CV_SHAPE_RECT, NULL), 1);
     cvDilate (filter->cvChA, filter->cvChA,
         cvCreateStructuringElementEx (3, 3, 1, 1, CV_SHAPE_RECT, NULL), 2);
     cvErode (filter->cvChA, filter->cvChA,
         cvCreateStructuringElementEx (3, 3, 1, 1, CV_SHAPE_RECT, NULL), 1);

     cvCvtColor (filter->cvChA, filter->cvRGB, CV_GRAY2RGB);
   }

   cvCopy (filter->cvRGB, filter->cvSkin, NULL);

   return GST_FLOW_OK;
 }

 /* entry point to initialize the plug-in
  * initialize the plug-in itself
  * register the element factories and other features
  */
 gboolean
 gst_skin_detect_plugin_init (GstPlugin * plugin)
 {
   /* debug category for fltering log messages
    *
    */
   GST_DEBUG_CATEGORY_INIT (gst_skin_detect_debug, "skindetect",
       0, "Performs skin detection on videos and images");

   return gst_element_register (plugin, "skindetect", GST_RANK_NONE,
       GST_TYPE_SKIN_DETECT);
 }
	/*
	* GStreamer
	* Copyright (C) 2013 Miguel Casas-Sanchez <miguelecasassanchez@gmail.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., 51 Franklin St, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/

	/**
	* SECTION:element-skindetect
	*
	* Human skin detection on videos and images
	*
	* <refsect2>
	* <title>Example launch line</title>
	* \|[
	* gst-launch-1.0 videotestsrc ! decodebin ! videoconvert ! skindetect ! videoconvert ! xvimagesink
	* ]\|
	* </refsect2>
	*/

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

	#include "gstskindetect.h"
	#include <opencv2/imgproc/imgproc_c.h>

	GST_DEBUG_CATEGORY_STATIC (gst_skin_detect_debug);
	#define GST_CAT_DEFAULT gst_skin_detect_debug

	/* Filter signals and args */
	enum
	{
	/* FILL ME */
	LAST_SIGNAL
	};

	enum
	{
	PROP_0,
	PROP_POSTPROCESS,
	PROP_METHOD,
	PROP_MASK
	};
	typedef enum
	{
	HSV,
	RGB
	} GstSkindetectMethod;

	#define GST_TYPE_SKIN_DETECT_METHOD (gst_skin_detect_method_get_type ())
	static GType
	gst_skin_detect_method_get_type (void)
	{
	static GType etype = 0;
	if (etype == 0) {
	static const GEnumValue values[] = {
	{HSV, "Classic HSV thresholding", "hsv"},
	{RGB, "Normalised-RGB colorspace thresholding", "rgb"},
	{0, NULL, NULL},
	};
	etype = g_enum_register_static ("GstSkindetectMethod", values);
	}
	return etype;
	}

	G_DEFINE_TYPE (GstSkinDetect, gst_skin_detect, GST_TYPE_OPENCV_VIDEO_FILTER);
	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_skin_detect_set_property (GObject * object, guint prop_id,
	const GValue * value, GParamSpec * pspec);
	static void gst_skin_detect_get_property (GObject * object, guint prop_id,
	GValue * value, GParamSpec * pspec);

	static GstFlowReturn gst_skin_detect_transform (GstOpencvVideoFilter * filter,
	GstBuffer * buf, IplImage * img, GstBuffer * outbuf, IplImage * outimg);

	static gboolean gst_skin_detect_stop (GstBaseTransform * basesrc);
	static gboolean
	gst_skin_detect_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 void gst_skin_detect_release_all_images (GstSkinDetect * filter);

	/* initialize the skindetect's class */
	static void
	gst_skin_detect_class_init (GstSkinDetectClass * klass)
	{
	GObjectClass *gobject_class;
	GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
	GstBaseTransformClass *basesrc_class = GST_BASE_TRANSFORM_CLASS (klass);
	GstOpencvVideoFilterClass *gstopencvbasefilter_class;

	gobject_class = (GObjectClass *) klass;
	gstopencvbasefilter_class = (GstOpencvVideoFilterClass *) klass;

	gobject_class->set_property = gst_skin_detect_set_property;
	gobject_class->get_property = gst_skin_detect_get_property;

	gstopencvbasefilter_class->cv_trans_func = gst_skin_detect_transform;

	g_object_class_install_property (gobject_class, PROP_POSTPROCESS,
	g_param_spec_boolean ("postprocess", "Postprocess",
	"Apply opening-closing to skin detection to extract large, significant blobs ",
	TRUE, (GParamFlags)
	(G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS)));
	g_object_class_install_property (gobject_class, PROP_METHOD,
	g_param_spec_enum ("method",
	"Method to use",
	"Method to use",
	GST_TYPE_SKIN_DETECT_METHOD, HSV,
	(GParamFlags) (G_PARAM_READWRITE \| G_PARAM_STATIC_STRINGS)));

	gst_element_class_set_static_metadata (element_class,
	"skindetect",
	"Filter/Effect/Video",
	"Performs non-parametric skin detection on input",
	"Miguel Casas-Sanchez <miguelecasassanchez@gmail.com>");

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

	basesrc_class->stop = gst_skin_detect_stop;
	gstopencvbasefilter_class->cv_set_caps = gst_skin_detect_set_caps;
	}

	/* initialize the new element
	* instantiate pads and add them to element
	* set pad calback functions
	* initialize instance structure
	*/
	static void
	gst_skin_detect_init (GstSkinDetect * filter)
	{
	filter->postprocess = TRUE;
	filter->method = HSV;

	gst_opencv_video_filter_set_in_place (GST_OPENCV_VIDEO_FILTER_CAST (filter),
	FALSE);
	}


	static void
	gst_skin_detect_set_property (GObject * object, guint prop_id,
	const GValue * value, GParamSpec * pspec)
	{
	GstSkinDetect *filter = GST_SKIN_DETECT (object);

	switch (prop_id) {
	case PROP_POSTPROCESS:
	filter->postprocess = g_value_get_boolean (value);
	break;
	case PROP_METHOD:
	filter->method = g_value_get_enum (value);
	break;
	default:
	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
	break;
	}
	}

	static void
	gst_skin_detect_get_property (GObject * object, guint prop_id,
	GValue * value, GParamSpec * pspec)
	{
	GstSkinDetect *filter = GST_SKIN_DETECT (object);

	switch (prop_id) {
	case PROP_POSTPROCESS:
	g_value_set_boolean (value, filter->postprocess);
	break;
	case PROP_METHOD:
	g_value_set_enum (value, filter->method);
	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_skin_detect_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)
	{
	GstSkinDetect *filter = GST_SKIN_DETECT (transform);
	CvSize size = cvSize (in_width, in_height);

	// If cvRGB is already allocated, it means there's a cap modification,
	// so release first all the images.
	if (NULL != filter->cvRGB)
	gst_skin_detect_release_all_images (filter);


	filter->cvRGB = cvCreateImageHeader (size, IPL_DEPTH_8U, 3);
	filter->cvSkin = cvCreateImageHeader (size, IPL_DEPTH_8U, 3);
	filter->cvChA = cvCreateImage (size, IPL_DEPTH_8U, 1);
	filter->width = in_width;
	filter->height = in_height;

	filter->cvHSV = cvCreateImage (size, IPL_DEPTH_8U, 3);
	filter->cvH = cvCreateImage (size, 8, 1); /* Hue component. */
	filter->cvH2 = cvCreateImage (size, 8, 1); /* Hue component, 2nd threshold */
	filter->cvS = cvCreateImage (size, 8, 1); /* Saturation component. */
	filter->cvV = cvCreateImage (size, 8, 1); /* Brightness component. */
	filter->cvSkinPixels1 = cvCreateImage (size, 8, 1); /* Greyscale output image */

	filter->cvR = cvCreateImage (size, 8, 1); /* R component. */
	filter->cvG = cvCreateImage (size, 8, 1); /* G component. */
	filter->cvB = cvCreateImage (size, 8, 1); /* B component. */
	filter->cvAll = cvCreateImage (size, IPL_DEPTH_32F, 1); /* (R+G+B) component. */
	filter->cvR2 = cvCreateImage (size, IPL_DEPTH_32F, 1); /* R component, 32bits */
	filter->cvRp = cvCreateImage (size, IPL_DEPTH_32F, 1); /* R' and >0.4 */
	filter->cvGp = cvCreateImage (size, IPL_DEPTH_32F, 1); /* G' and > 0.28 */
	filter->cvRp2 = cvCreateImage (size, IPL_DEPTH_32F, 1); /* R' <0.6 */
	filter->cvGp2 = cvCreateImage (size, IPL_DEPTH_32F, 1); /* G' <0.4 */
	filter->cvSkinPixels2 = cvCreateImage (size, IPL_DEPTH_32F, 1); /* Greyscale output image. */
	filter->cvdraft = cvCreateImage (size, IPL_DEPTH_8U, 1); /* Greyscale output image. */

	return TRUE;
	}

	/* Clean up */
	static gboolean
	gst_skin_detect_stop (GstBaseTransform * basesrc)
	{
	GstSkinDetect *filter = GST_SKIN_DETECT (basesrc);

	if (filter->cvRGB != NULL)
	gst_skin_detect_release_all_images (filter);
	return TRUE;
	}

	static void
	gst_skin_detect_release_all_images (GstSkinDetect * filter)
	{
	cvReleaseImage (&filter->cvRGB);
	cvReleaseImage (&filter->cvSkin);
	cvReleaseImage (&filter->cvChA);

	cvReleaseImage (&filter->cvHSV);
	cvReleaseImage (&filter->cvH);
	cvReleaseImage (&filter->cvH2);
	cvReleaseImage (&filter->cvS);
	cvReleaseImage (&filter->cvV);
	cvReleaseImage (&filter->cvSkinPixels1);

	cvReleaseImage (&filter->cvR);
	cvReleaseImage (&filter->cvG);
	cvReleaseImage (&filter->cvB);
	cvReleaseImage (&filter->cvAll);
	cvReleaseImage (&filter->cvR2);
	cvReleaseImage (&filter->cvRp);
	cvReleaseImage (&filter->cvGp);
	cvReleaseImage (&filter->cvRp2);
	cvReleaseImage (&filter->cvGp2);
	cvReleaseImage (&filter->cvSkinPixels2);
	cvReleaseImage (&filter->cvdraft);
	}

	static GstFlowReturn
	gst_skin_detect_transform (GstOpencvVideoFilter * base, GstBuffer * buf,
	IplImage * img, GstBuffer * outbuf, IplImage * outimg)
	{
	GstSkinDetect *filter = GST_SKIN_DETECT (base);

	filter->cvRGB->imageData = (char *) img->imageData;
	filter->cvSkin->imageData = (char *) outimg->imageData;

	/* SKIN COLOUR BLOB DETECTION */
	if (HSV == filter->method) {
	cvCvtColor (filter->cvRGB, filter->cvHSV, CV_RGB2HSV);
	cvSplit (filter->cvHSV, filter->cvH, filter->cvS, filter->cvV, 0); /* Extract the 3 color components. */

	/* Detect which pixels in each of the H, S and V channels are probably skin pixels.
	Assume that skin has a Hue between 0 to 18 (out of 180), and Saturation above 50, and Brightness above 80. */
	cvThreshold (filter->cvH, filter->cvH2, 10, UCHAR_MAX, CV_THRESH_BINARY); /* (hue > 10) */
	cvThreshold (filter->cvH, filter->cvH, 20, UCHAR_MAX, CV_THRESH_BINARY_INV); /* (hue < 20) */
	cvThreshold (filter->cvS, filter->cvS, 48, UCHAR_MAX, CV_THRESH_BINARY); /* (sat > 48) */
	cvThreshold (filter->cvV, filter->cvV, 80, UCHAR_MAX, CV_THRESH_BINARY); /* (val > 80) */

	/* erode the HUE to get rid of noise. */
	cvErode (filter->cvH, filter->cvH, NULL, 1);

	/* Combine all 3 thresholded color components, so that an output pixel will only
	be white (255) if the H, S and V pixels were also white.
	imageSkin = (hue > 10) ^ (hue < 20) ^ (sat > 48) ^ (val > 80), where ^ mean pixels-wise AND */
	cvAnd (filter->cvH, filter->cvS, filter->cvSkinPixels1, NULL);
	cvAnd (filter->cvSkinPixels1, filter->cvH2, filter->cvSkinPixels1, NULL);
	cvAnd (filter->cvSkinPixels1, filter->cvV, filter->cvSkinPixels1, NULL);

	cvCvtColor (filter->cvSkinPixels1, filter->cvRGB, CV_GRAY2RGB);
	} else if (RGB == filter->method) {
	cvSplit (filter->cvRGB, filter->cvR, filter->cvG, filter->cvB, 0); /* Extract the 3 color components. */
	cvAdd (filter->cvR, filter->cvG, filter->cvAll, NULL);
	cvAdd (filter->cvB, filter->cvAll, filter->cvAll, NULL); /* All = R + G + B */
	cvDiv (filter->cvR, filter->cvAll, filter->cvRp, 1.0); /* R' = R / ( R + G + B) */
	cvDiv (filter->cvG, filter->cvAll, filter->cvGp, 1.0); /* G' = G / ( R + G + B) */

	cvConvertScale (filter->cvR, filter->cvR2, 1.0, 0.0);
	cvCopy (filter->cvGp, filter->cvGp2, NULL);
	cvCopy (filter->cvRp, filter->cvRp2, NULL);

	cvThreshold (filter->cvR2, filter->cvR2, 60, UCHAR_MAX, CV_THRESH_BINARY); /* (R > 60) */
	cvThreshold (filter->cvRp, filter->cvRp, 0.42, UCHAR_MAX, CV_THRESH_BINARY); /* (R'> 0.4) */
	cvThreshold (filter->cvRp2, filter->cvRp2, 0.6, UCHAR_MAX, CV_THRESH_BINARY_INV); /* (R'< 0.6) */
	cvThreshold (filter->cvGp, filter->cvGp, 0.28, UCHAR_MAX, CV_THRESH_BINARY); /* (G'> 0.28) */
	cvThreshold (filter->cvGp2, filter->cvGp2, 0.4, UCHAR_MAX, CV_THRESH_BINARY_INV); /* (G'< 0.4) */

	/* Combine all 3 thresholded color components, so that an output pixel will only
	be white (255) if the H, S and V pixels were also white. */

	cvAnd (filter->cvR2, filter->cvRp, filter->cvSkinPixels2, NULL);
	cvAnd (filter->cvRp, filter->cvSkinPixels2, filter->cvSkinPixels2, NULL);
	cvAnd (filter->cvRp2, filter->cvSkinPixels2, filter->cvSkinPixels2, NULL);
	cvAnd (filter->cvGp, filter->cvSkinPixels2, filter->cvSkinPixels2, NULL);
	cvAnd (filter->cvGp2, filter->cvSkinPixels2, filter->cvSkinPixels2, NULL);

	cvConvertScale (filter->cvSkinPixels2, filter->cvdraft, 1.0, 0.0);
	cvCvtColor (filter->cvdraft, filter->cvRGB, CV_GRAY2RGB);
	}

	/* After this we have a RGB Black and white image with the skin, in
	filter->cvRGB. We can postprocess by applying 1 erode-dilate and 1
	dilate-erode, or alternatively 1 opening-closing all together, with
	the goal of removing small (spurious) skin spots and creating large
	connected areas */
	if (filter->postprocess) {
	cvSplit (filter->cvRGB, filter->cvChA, NULL, NULL, NULL);

	cvErode (filter->cvChA, filter->cvChA,
	cvCreateStructuringElementEx (3, 3, 1, 1, CV_SHAPE_RECT, NULL), 1);
	cvDilate (filter->cvChA, filter->cvChA,
	cvCreateStructuringElementEx (3, 3, 1, 1, CV_SHAPE_RECT, NULL), 2);
	cvErode (filter->cvChA, filter->cvChA,
	cvCreateStructuringElementEx (3, 3, 1, 1, CV_SHAPE_RECT, NULL), 1);

	cvCvtColor (filter->cvChA, filter->cvRGB, CV_GRAY2RGB);
	}

	cvCopy (filter->cvRGB, filter->cvSkin, NULL);

	return GST_FLOW_OK;
	}

	/* entry point to initialize the plug-in
	* initialize the plug-in itself
	* register the element factories and other features
	*/
	gboolean
	gst_skin_detect_plugin_init (GstPlugin * plugin)
	{
	/* debug category for fltering log messages
	*
	*/
	GST_DEBUG_CATEGORY_INIT (gst_skin_detect_debug, "skindetect",
	0, "Performs skin detection on videos and images");

	return gst_element_register (plugin, "skindetect", GST_RANK_NONE,
	GST_TYPE_SKIN_DETECT);
	}