osmap.proto

/**
* This file is part of OSMAP.
*
* Copyright (C) 2018-2019 Alejandro Silvestri <alejandrosilvestri at gmail>
* For more information see <https://github.com/AlejandroSilvestri/osmap>
*
* OSMAP is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* OSMAP 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with OSMAP. If not, see <http://www.gnu.org/licenses/>.
*/

/*
OSMAP: Map serialization structure definition, for ORB-SLAM2.
Messages are ORB-SLAM2 objects minimal serialization.  They ommit not used properties: those effimeral and those that can be regenerated.
Repeated fields can be ommited.  Their ommission can compromise the map integrity.
*/

syntax = "proto3";

// 256 bits descriptor: 32 bytes, 8 uint32.  Exactly 8 fixed32 required.
message SerializedDescriptor{
  repeated fixed32 block = 1;
}

// Pose, first 12 elements in an homogeneous 4x4 pose matrix. Exactly 12 float required.
message SerializedPose{
  repeated float element = 1;
}


// 3x1 Mat 3D position, all 3 fields required.
message SerializedPosition{
  float x = 1;
  float y = 2;
  float z = 3;
}

//  KeyPoint, all 4 fields required.
message SerializedKeypoint{
  float ptx    = 1;
  float pty    = 2;
  float angle  = 3;
  float octave = 4;
}

// Intrinsic matrix K, all 4 fields required.
message SerializedK{
  float fx = 1;
  float fy = 2;
  float cx = 3;
  float cy = 4;
}

message SerializedKArray{
  repeated SerializedK k = 1;
}

// MapPoint, all fields optional, should provide position at least.
message SerializedMappoint{
  uint32 id                       = 1;  // mnId
  SerializedPosition position     = 2;  // mWorldPos
  float visible                   = 3;  // mnVisible
  float found                     = 4;  // mnFound
  SerializedDescriptor briefdescriptor = 5;  // mDescriptor, very optional.  This field is named briefdescriptor instead of descriptor because the latter es a reserved word in protocol buffers.
}

message SerializedMappointArray{
  repeated SerializedMappoint mappoint = 1;
}


// KeyFrame, all fields optional, should provide pose at least.
message SerializedKeyframe{
  uint32 id             		= 1;  // mnId
  SerializedPose pose   		= 2;  // mTcw
  SerializedK kmatrix			= 3;  // K matrix, alternative to index k
  uint32 kindex         		= 4;  // index to matrix list K, ignored if kmatrix is present
  repeated uint32 loopedgesids 	= 5;  // indexes to keyframes connected in a loop
  double timestamp				= 6;  // Time stamp
}

message SerializedKeyframeArray{
  repeated SerializedKeyframe keyframe = 1;
}


// One observed feature in a keyframe.
message SerializedFeature{
  uint32 mappoint_id              = 2;  // mappoint id used to construct mvpMapPoints
  SerializedKeypoint keypoint     = 3;  // element of mvKeysUn
  SerializedDescriptor briefdescriptor = 4;  // row of mDescriptors.  This field is named briefdescriptor instead of descriptor because the latter es a reserved word in protocol buffers.
}

// All observed features in a keyframe.  keyframe_id required.
message SerializedKeyframeFeatures{
  uint32 keyframe_id         = 1;  // kfId, keyframe id
  repeated SerializedFeature feature = 2;
}

message SerializedKeyframeFeaturesArray{
  repeated SerializedKeyframeFeatures feature = 1;
}