{
  "id": 499282,
  "title": "How is the world coordinate system defined?  ",
  "url": "/competitions/image-matching-challenge-2024/discussion/499282",
  "author_name": "",
  "post_date": "2024-05-01T09:25:38.748135600Z",
  "votes": 4,
  "comment_count": 3,
  "views": 0,
  "content": "<p>Hey! </p>\n<p>New to this comp, absolute noob question:</p>\n<p>So I understand that every camera center is estimated by rotation and translation of the ground truth. However, I do not know how the origin or the orientation of the world coordinate system looks like. In my understanding, the location and orientation of the world coordinate system will affect the rotation and translation matrix for each camera.  Please do help me with an explanation or reference if possible. Do let me know if I have some inaccuracies in the above basics. </p>\n<p>Thanks!</p>",
  "messages": [
    {
      "id": "2786358",
      "postDate": "05/01/2024 09:25:38",
      "content": "<p>Hey! </p>\n<p>New to this comp, absolute noob question:</p>\n<p>So I understand that every camera center is estimated by rotation and translation of the ground truth. However, I do not know how the origin or the orientation of the world coordinate system looks like. In my understanding, the location and orientation of the world coordinate system will affect the rotation and translation matrix for each camera.  Please do help me with an explanation or reference if possible. Do let me know if I have some inaccuracies in the above basics. </p>\n<p>Thanks!</p>",
      "rawMarkdown": "Hey! \n\nNew to this comp, absolute noob question:\n\nSo I understand that every camera center is estimated by rotation and translation of the ground truth. However, I do not know how the origin or the orientation of the world coordinate system looks like. In my understanding, the location and orientation of the world coordinate system will affect the rotation and translation matrix for each camera.  Please do help me with an explanation or reference if possible. Do let me know if I have some inaccuracies in the above basics. \n\nThanks!",
      "votes": null
    },
    {
      "id": "2803537",
      "postDate": "05/09/2024 14:48:38",
      "content": "<p>Hi, from what I understand, the evaluation metric estimates a transformation that aligns predicted camera coordinates with the ground truth(by a RANSAC-like algorithm). So we just need the relative camera poses, no need for absolute world coordinates.</p>",
      "rawMarkdown": "Hi, from what I understand, the evaluation metric estimates a transformation that aligns predicted camera coordinates with the ground truth(by a RANSAC-like algorithm). So we just need the relative camera poses, no need for absolute world coordinates.",
      "votes": null
    },
    {
      "id": "2803884",
      "postDate": "05/09/2024 17:19:54",
      "content": "<p>That is correct.</p>",
      "rawMarkdown": "That is correct.",
      "votes": null
    },
    {
      "id": "2809176",
      "postDate": "05/12/2024 15:12:28",
      "content": "<p>Do you find the answer?</p>",
      "rawMarkdown": "Do you find the answer?",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 2803537,
      "author_name": "scarlet390625",
      "author_url": "",
      "post_date": "05/09/2024 14:48:38",
      "content": "<p>Hi, from what I understand, the evaluation metric estimates a transformation that aligns predicted camera coordinates with the ground truth(by a RANSAC-like algorithm). So we just need the relative camera poses, no need for absolute world coordinates.</p>",
      "votes": null,
      "replies": [
        {
          "id": 2803884,
          "author_name": "oldufo",
          "author_url": "",
          "post_date": "05/09/2024 17:19:54",
          "content": "<p>That is correct.</p>",
          "votes": null,
          "replies": []
        }
      ]
    },
    {
      "id": 2809176,
      "author_name": "jonathanthompsons",
      "author_url": "",
      "post_date": "05/12/2024 15:12:28",
      "content": "<p>Do you find the answer?</p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "2786358": "Hey! \n\nNew to this comp, absolute noob question:\n\nSo I understand that every camera center is estimated by rotation and translation of the ground truth. However, I do not know how the origin or the orientation of the world coordinate system looks like. In my understanding, the location and orientation of the world coordinate system will affect the rotation and translation matrix for each camera.  Please do help me with an explanation or reference if possible. Do let me know if I have some inaccuracies in the above basics. \n\nThanks!",
    "2803537": "Hi, from what I understand, the evaluation metric estimates a transformation that aligns predicted camera coordinates with the ground truth(by a RANSAC-like algorithm). So we just need the relative camera poses, no need for absolute world coordinates.",
    "2803884": "That is correct.",
    "2809176": "Do you find the answer?"
  },
  "source": "meta"
}