cv_bridge.cpp

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#include <map>

#include <boost/make_shared.hpp>

#include <opencv2/imgproc/imgproc.hpp>

#include <sensor_msgs/image_encodings.h>

#include <cv_bridge/cv_bridge.h>

namespace enc = sensor_msgs::image_encodings;

namespace cv_bridge {

int getCvType(const std::string& encoding)
{
  // Check for the most common encodings first
  if (encoding == enc::BGR8)   return CV_8UC3;
  if (encoding == enc::MONO8)  return CV_8UC1;
  if (encoding == enc::RGB8)   return CV_8UC3;
  if (encoding == enc::MONO16) return CV_16UC1;
  if (encoding == enc::BGR16)  return CV_16UC3;
  if (encoding == enc::RGB16)  return CV_16UC3;
  if (encoding == enc::BGRA8)  return CV_8UC4;
  if (encoding == enc::RGBA8)  return CV_8UC4;
  if (encoding == enc::BGRA16) return CV_16UC4;
  if (encoding == enc::RGBA16) return CV_16UC4;

  // For bayer, return one-channel
  if (encoding == enc::BAYER_RGGB8) return CV_8UC1;
  if (encoding == enc::BAYER_BGGR8) return CV_8UC1;
  if (encoding == enc::BAYER_GBRG8) return CV_8UC1;
  if (encoding == enc::BAYER_GRBG8) return CV_8UC1;
  if (encoding == enc::BAYER_RGGB16) return CV_16UC1;
  if (encoding == enc::BAYER_BGGR16) return CV_16UC1;
  if (encoding == enc::BAYER_GBRG16) return CV_16UC1;
  if (encoding == enc::BAYER_GRBG16) return CV_16UC1;

  // Miscellaneous
  if (encoding == enc::YUV422) return CV_8UC2;

  // Check all the generic content encodings
#define CHECK_ENCODING(code)                            \
  if (encoding == enc::TYPE_##code) return CV_##code    \
  /***/
#define CHECK_CHANNEL_TYPE(t)                   \
  CHECK_ENCODING(t##1);                         \
  CHECK_ENCODING(t##2);                         \
  CHECK_ENCODING(t##3);                         \
  CHECK_ENCODING(t##4);                         \
  /***/

  CHECK_CHANNEL_TYPE(8UC);
  CHECK_CHANNEL_TYPE(8SC);
  CHECK_CHANNEL_TYPE(16UC);
  CHECK_CHANNEL_TYPE(16SC);
  CHECK_CHANNEL_TYPE(32SC);
  CHECK_CHANNEL_TYPE(32FC);
  CHECK_CHANNEL_TYPE(64FC);

#undef CHECK_CHANNEL_TYPE
#undef CHECK_ENCODING

  throw Exception("Unrecognized image encoding [" + encoding + "]");
}


enum Format { INVALID = -1, GRAY = 0, RGB, BGR, RGBA, BGRA, YUV422, BAYER_RGGB, BAYER_BGGR, BAYER_GBRG, BAYER_GRBG};

Format getFormat(const std::string& encoding)
{
  if ((encoding == enc::MONO8) || (encoding == enc::MONO16)) return GRAY;
  if ((encoding == enc::BGR8) || (encoding == enc::BGR16))  return BGR;
  if ((encoding == enc::RGB8) || (encoding == enc::RGB16))  return RGB;
  if ((encoding == enc::BGRA8) || (encoding == enc::BGRA16))  return BGRA;
  if ((encoding == enc::RGBA8) || (encoding == enc::RGBA16))  return RGBA;
  if (encoding == enc::YUV422) return YUV422;

  if ((encoding == enc::BAYER_RGGB8) || (encoding == enc::BAYER_RGGB16)) return BAYER_RGGB;
  if ((encoding == enc::BAYER_BGGR8) || (encoding == enc::BAYER_BGGR16)) return BAYER_BGGR;
  if ((encoding == enc::BAYER_GBRG8) || (encoding == enc::BAYER_GBRG16)) return BAYER_GBRG;
  if ((encoding == enc::BAYER_GRBG8) || (encoding == enc::BAYER_GRBG16)) return BAYER_GRBG;

  // We don't support conversions to/from other types
  return INVALID;
}

static const int SAME_FORMAT = -1;

std::map<std::pair<Format, Format>, std::vector<int> > getConversionCodes() {
  std::map<std::pair<Format, Format>, std::vector<int> > res;
  for(int i=0; i<=5; ++i)
    res[std::pair<Format, Format>(Format(i),Format(i))].push_back(SAME_FORMAT);
  res[std::make_pair(GRAY, RGB)].push_back(CV_GRAY2RGB);
  res[std::make_pair(GRAY, BGR)].push_back(CV_GRAY2BGR);
  res[std::make_pair(GRAY, RGBA)].push_back(CV_GRAY2RGBA);
  res[std::make_pair(GRAY, BGRA)].push_back(CV_GRAY2BGRA);

  res[std::make_pair(RGB, GRAY)].push_back(CV_RGB2GRAY);
  res[std::make_pair(RGB, BGR)].push_back(CV_RGB2BGR);
  res[std::make_pair(RGB, RGBA)].push_back(CV_RGB2RGBA);
  res[std::make_pair(RGB, BGRA)].push_back(CV_RGB2BGRA);

  res[std::make_pair(BGR, GRAY)].push_back(CV_BGR2GRAY);
  res[std::make_pair(BGR, RGB)].push_back(CV_BGR2RGB);
  res[std::make_pair(BGR, RGBA)].push_back(CV_BGR2RGBA);
  res[std::make_pair(BGR, BGRA)].push_back(CV_BGR2BGRA);

  res[std::make_pair(RGBA, GRAY)].push_back(CV_RGBA2GRAY);
  res[std::make_pair(RGBA, RGB)].push_back(CV_RGBA2RGB);
  res[std::make_pair(RGBA, BGR)].push_back(CV_RGBA2BGR);
  res[std::make_pair(RGBA, BGRA)].push_back(CV_RGBA2BGRA);

  res[std::make_pair(BGRA, GRAY)].push_back(CV_BGRA2GRAY);
  res[std::make_pair(BGRA, RGB)].push_back(CV_BGRA2RGB);
  res[std::make_pair(BGRA, BGR)].push_back(CV_BGRA2BGR);
  res[std::make_pair(BGRA, RGBA)].push_back(CV_BGRA2RGBA);

  res[std::make_pair(YUV422, GRAY)].push_back(CV_YUV2GRAY_UYVY);
  res[std::make_pair(YUV422, RGB)].push_back(CV_YUV2RGB_UYVY);
  res[std::make_pair(YUV422, BGR)].push_back(CV_YUV2BGR_UYVY);
  res[std::make_pair(YUV422, RGBA)].push_back(CV_YUV2RGBA_UYVY);
  res[std::make_pair(YUV422, BGRA)].push_back(CV_YUV2BGRA_UYVY);

  // Deal with Bayer
  res[std::make_pair(BAYER_RGGB, GRAY)].push_back(CV_BayerBG2GRAY);
  res[std::make_pair(BAYER_RGGB, RGB)].push_back(CV_BayerBG2RGB);
  res[std::make_pair(BAYER_RGGB, BGR)].push_back(CV_BayerBG2BGR);

  res[std::make_pair(BAYER_BGGR, GRAY)].push_back(CV_BayerRG2GRAY);
  res[std::make_pair(BAYER_BGGR, RGB)].push_back(CV_BayerRG2RGB);
  res[std::make_pair(BAYER_BGGR, BGR)].push_back(CV_BayerRG2BGR);

  res[std::make_pair(BAYER_GBRG, GRAY)].push_back(CV_BayerGR2GRAY);
  res[std::make_pair(BAYER_GBRG, RGB)].push_back(CV_BayerGR2RGB);
  res[std::make_pair(BAYER_GBRG, BGR)].push_back(CV_BayerGR2BGR);

  res[std::make_pair(BAYER_GRBG, GRAY)].push_back(CV_BayerGB2GRAY);
  res[std::make_pair(BAYER_GRBG, RGB)].push_back(CV_BayerGB2RGB);
  res[std::make_pair(BAYER_GRBG, BGR)].push_back(CV_BayerGB2BGR);

  return res;
}

const std::vector<int> getConversionCode(std::string src_encoding, std::string dst_encoding)
{
  Format src_format = getFormat(src_encoding);
  Format dst_format = getFormat(dst_encoding);
  bool is_src_color_format = sensor_msgs::image_encodings::isColor(src_encoding) ||
                             sensor_msgs::image_encodings::isMono(src_encoding) ||
                             sensor_msgs::image_encodings::isBayer(src_encoding) ||
                             (src_encoding == sensor_msgs::image_encodings::YUV422);
  bool is_dst_color_format = sensor_msgs::image_encodings::isColor(dst_encoding) ||
                             sensor_msgs::image_encodings::isMono(dst_encoding) ||
                             sensor_msgs::image_encodings::isBayer(dst_encoding) ||
                             (dst_encoding == sensor_msgs::image_encodings::YUV422);
  bool is_num_channels_the_same = (sensor_msgs::image_encodings::numChannels(src_encoding) == sensor_msgs::image_encodings::numChannels(dst_encoding));

  // If we have no color info in the source, we can only convert to the same format which
  // was resolved in the previous condition. Otherwise, fail
  if (!is_src_color_format) {
    if (is_dst_color_format)
      throw Exception("[" + src_encoding + "] is not a color format. but [" + dst_encoding +
                      "] is. The conversion does not make sense");
    if (!is_num_channels_the_same)
      throw Exception("[" + src_encoding + "] and [" + dst_encoding + "] do not have the same number of channel");
    return std::vector<int>(1, SAME_FORMAT);
  }

  // If we are converting from a color type to a non color type, we can only do so if we stick
  // to the number of channels
  if (!is_dst_color_format) {
    if (!is_num_channels_the_same)
      throw Exception("[" + src_encoding + "] is a color format but [" + dst_encoding + "] " +
                      "is not so they must have the same OpenCV type, CV_8UC3, CV16UC1 ....");
    return std::vector<int>(1, SAME_FORMAT);
  }

  // If we are converting from a color type to another type, then everything is fine
  static const std::map<std::pair<Format, Format>, std::vector<int> > CONVERSION_CODES = getConversionCodes();

  std::pair<Format, Format> key(src_format, dst_format);
  std::map<std::pair<Format, Format>, std::vector<int> >::const_iterator val = CONVERSION_CODES.find(key);
  if (val == CONVERSION_CODES.end())
    throw Exception("Unsupported conversion from [" + src_encoding +
                      "] to [" + dst_encoding + "]");

  // And deal with depth differences
  std::vector<int> res = val->second;
  if (enc::bitDepth(src_encoding) != enc::bitDepth(dst_encoding))
    res.push_back(SAME_FORMAT);

  return val->second;
}

cv::Mat matFromImage(const sensor_msgs::Image& source)
{
  int source_type = getCvType(source.encoding);
  int byte_depth = enc::bitDepth(source.encoding) / 8;
  int num_channels = enc::numChannels(source.encoding);

  if (source.step < source.width * byte_depth * num_channels)
  {
    std::stringstream ss;
    ss << "Image is wrongly formed: step < width * byte_depth * num_channels  or  " << source.step << " != " <<
        source.width << " * " << byte_depth << " * " << num_channels;
    throw Exception(ss.str());
  }

  if (source.height * source.step != source.data.size())
  {
    std::stringstream ss;
    ss << "Image is wrongly formed: height * step != size  or  " << source.height << " * " <<
              source.step << " != " << source.data.size();
    throw Exception(ss.str());
  }

  return cv::Mat(source.height, source.width, source_type,
                       const_cast<uchar*>(&source.data[0]), source.step);
}

// Internal, used by toCvCopy and cvtColor
CvImagePtr toCvCopyImpl(const cv::Mat& source,
                        const std_msgs::Header& src_header,
                        const std::string& src_encoding,
                        const std::string& dst_encoding)
{
  
  // Copy metadata
  CvImagePtr ptr = boost::make_shared<CvImage>();
  ptr->header = src_header;
  
  // Copy to new buffer if same encoding requested
  if (dst_encoding.empty() || dst_encoding == src_encoding)
  {
    ptr->encoding = src_encoding;
    source.copyTo(ptr->image);
  }
  else
  {
    // Convert the source data to the desired encoding
    const std::vector<int> conversion_codes = getConversionCode(src_encoding, dst_encoding);
    cv::Mat image1 = source;
    cv::Mat image2;
    for(size_t i=0; i<conversion_codes.size(); ++i) {
      int conversion_code = conversion_codes[i];
      if (conversion_code == SAME_FORMAT)
      {
        // Same number of channels, but different bit depth
        double alpha = 1.0;
        int src_depth = enc::bitDepth(src_encoding);
        int dst_depth = enc::bitDepth(dst_encoding);
        // Do scaling between CV_8U [0,255] and CV_16U [0,65535] images.
        if (src_depth == 8 && dst_depth == 16)
          image1.convertTo(image2, getCvType(dst_encoding), 65535. / 255.);
        else if (src_depth == 16 && dst_depth == 8)
          image1.convertTo(image2, getCvType(dst_encoding), 255. / 65535.);
        else
          image1.convertTo(image2, getCvType(dst_encoding));
      }
      else
      {
        // Perform color conversion
        cv::cvtColor(image1, image2, conversion_code);
      }
      image1 = image2;
    }
    ptr->image = image2;
    ptr->encoding = dst_encoding;
  }

  return ptr;
}


sensor_msgs::ImagePtr CvImage::toImageMsg() const
{
  sensor_msgs::ImagePtr ptr = boost::make_shared<sensor_msgs::Image>();
  toImageMsg(*ptr);
  return ptr;
}

void CvImage::toImageMsg(sensor_msgs::Image& ros_image) const
{
  ros_image.header = header;
  ros_image.height = image.rows;
  ros_image.width = image.cols;
  ros_image.encoding = encoding;
  ros_image.is_bigendian = false;
  ros_image.step = image.cols * image.elemSize();
  size_t size = ros_image.step * image.rows;
  ros_image.data.resize(size);

  if (image.isContinuous())
  {
    memcpy((char*)(&ros_image.data[0]), image.data, size);
  }
  else
  {
    // Copy by row by row
    uchar* ros_data_ptr = (uchar*)(&ros_image.data[0]);
    uchar* cv_data_ptr = image.data;
    for (int i = 0; i < image.rows; ++i)
    {
      memcpy(ros_data_ptr, cv_data_ptr, ros_image.step);
      ros_data_ptr += ros_image.step;
      cv_data_ptr += image.step;
    }
  }
}

// Deep copy data, returnee is mutable
CvImagePtr toCvCopy(const sensor_msgs::ImageConstPtr& source,
                    const std::string& encoding)
{
  return toCvCopy(*source, encoding);
}

CvImagePtr toCvCopy(const sensor_msgs::Image& source,
                    const std::string& encoding)
{
  // Construct matrix pointing to source data
  return toCvCopyImpl(matFromImage(source), source.header, source.encoding, encoding);
}

// Share const data, returnee is immutable
CvImageConstPtr toCvShare(const sensor_msgs::ImageConstPtr& source,
                          const std::string& encoding)
{
  return toCvShare(*source, source, encoding);
}

CvImageConstPtr toCvShare(const sensor_msgs::Image& source,
                          const boost::shared_ptr<void const>& tracked_object,
                          const std::string& encoding)
{
  if (!encoding.empty() && source.encoding != encoding)
    return toCvCopy(source, encoding);

  CvImagePtr ptr = boost::make_shared<CvImage>();
  ptr->header = source.header;
  ptr->encoding = source.encoding;
  ptr->tracked_object_ = tracked_object;
  ptr->image = matFromImage(source);
  return ptr;
}

CvImagePtr cvtColor(const CvImageConstPtr& source,
                    const std::string& encoding)
{
  return toCvCopyImpl(source->image, source->header, source->encoding, encoding);
}

} //namespace cv_bridge