{
  "id": 414847,
  "title": "LAF - What are they?",
  "url": "/competitions/image-matching-challenge-2023/discussion/414847",
  "author_name": "",
  "post_date": "2023-06-03T15:21:12.859682300Z",
  "votes": 5,
  "comment_count": 4,
  "views": 0,
  "content": "<p>What exactly are LAFs and where can i find about them.<br>\nThis might be a redundant discussion but i was out of options. I tried exploring, but all i found was papers on LAF and no basic explanation.</p>\n<p>It would be nice if someone helped me out.<br>\nEdit: follow up question of mine is, in Kornia its shape is specified as 2,3. Is there any explanation for it?</p>",
  "messages": [
    {
      "id": "2286606",
      "postDate": "06/03/2023 15:21:12",
      "content": "<p>What exactly are LAFs and where can i find about them.<br>\nThis might be a redundant discussion but i was out of options. I tried exploring, but all i found was papers on LAF and no basic explanation.</p>\n<p>It would be nice if someone helped me out.<br>\nEdit: follow up question of mine is, in Kornia its shape is specified as 2,3. Is there any explanation for it?</p>",
      "rawMarkdown": "What exactly are LAFs and where can i find about them.\nThis might be a redundant discussion but i was out of options. I tried exploring, but all i found was papers on LAF and no basic explanation.\n\nIt would be nice if someone helped me out.\nEdit: follow up question of mine is, in Kornia its shape is specified as 2,3. Is there any explanation for it?",
      "votes": null
    },
    {
      "id": "2286612",
      "postDate": "06/03/2023 15:25:36",
      "content": "<p>This are local affine frames - local features with center, scale, orientation and affine (ellipse) shape.<br>\nCheck slides here <a href=\"https://cvpr22-affine-tutorial.com/program.html\" target=\"_blank\">https://cvpr22-affine-tutorial.com/program.html</a></p>",
      "rawMarkdown": "This are local affine frames - local features with center, scale, orientation and affine (ellipse) shape.\nCheck slides here https://cvpr22-affine-tutorial.com/program.html",
      "votes": null
    },
    {
      "id": "2287067",
      "postDate": "06/04/2023 05:27:25",
      "content": "<p>thanks a lot, can you also guide me to why is its shape is 2,3</p>",
      "rawMarkdown": "thanks a lot, can you also guide me to why is its shape is 2,3",
      "votes": null
    },
    {
      "id": "2288959",
      "postDate": "06/05/2023 20:02:51",
      "content": "<p>Because you have 6 parameters: [A; (x, y)]<br>\nA is [2x2] matrix, which encodes shape, orientation and scale.</p>\n<p>Check here:</p>\n<p><a href=\"https://cw.fel.cvut.cz/wiki/courses/mpv/labs/2_correspondence_problem/\" target=\"_blank\">https://cw.fel.cvut.cz/wiki/courses/mpv/labs/2_correspondence_problem/</a><br>\nspecifically <code>Geometric normalization</code> part.</p>",
      "rawMarkdown": "Because you have 6 parameters: [A; (x, y)]\nA is [2x2] matrix, which encodes shape, orientation and scale.\n\nCheck here:\n\nhttps://cw.fel.cvut.cz/wiki/courses/mpv/labs/2_correspondence_problem/\nspecifically `Geometric normalization` part.",
      "votes": null
    },
    {
      "id": "2288961",
      "postDate": "06/05/2023 20:09:53",
      "content": "<p>Thanks a lot</p>",
      "rawMarkdown": "Thanks a lot",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 2286612,
      "author_name": "oldufo",
      "author_url": "",
      "post_date": "06/03/2023 15:25:36",
      "content": "<p>This are local affine frames - local features with center, scale, orientation and affine (ellipse) shape.<br>\nCheck slides here <a href=\"https://cvpr22-affine-tutorial.com/program.html\" target=\"_blank\">https://cvpr22-affine-tutorial.com/program.html</a></p>",
      "votes": null,
      "replies": [
        {
          "id": 2287067,
          "author_name": "bhavesjain",
          "author_url": "",
          "post_date": "06/04/2023 05:27:25",
          "content": "<p>thanks a lot, can you also guide me to why is its shape is 2,3</p>",
          "votes": null,
          "replies": [
            {
              "id": 2288959,
              "author_name": "oldufo",
              "author_url": "",
              "post_date": "06/05/2023 20:02:51",
              "content": "<p>Because you have 6 parameters: [A; (x, y)]<br>\nA is [2x2] matrix, which encodes shape, orientation and scale.</p>\n<p>Check here:</p>\n<p><a href=\"https://cw.fel.cvut.cz/wiki/courses/mpv/labs/2_correspondence_problem/\" target=\"_blank\">https://cw.fel.cvut.cz/wiki/courses/mpv/labs/2_correspondence_problem/</a><br>\nspecifically <code>Geometric normalization</code> part.</p>",
              "votes": null,
              "replies": [
                {
                  "id": 2288961,
                  "author_name": "bhavesjain",
                  "author_url": "",
                  "post_date": "06/05/2023 20:09:53",
                  "content": "<p>Thanks a lot</p>",
                  "votes": null,
                  "replies": []
                }
              ]
            }
          ]
        }
      ]
    }
  ],
  "raw_markdown_by_id": {
    "2286606": "What exactly are LAFs and where can i find about them.\nThis might be a redundant discussion but i was out of options. I tried exploring, but all i found was papers on LAF and no basic explanation.\n\nIt would be nice if someone helped me out.\nEdit: follow up question of mine is, in Kornia its shape is specified as 2,3. Is there any explanation for it?",
    "2286612": "This are local affine frames - local features with center, scale, orientation and affine (ellipse) shape.\nCheck slides here https://cvpr22-affine-tutorial.com/program.html",
    "2287067": "thanks a lot, can you also guide me to why is its shape is 2,3",
    "2288959": "Because you have 6 parameters: [A; (x, y)]\nA is [2x2] matrix, which encodes shape, orientation and scale.\n\nCheck here:\n\nhttps://cw.fel.cvut.cz/wiki/courses/mpv/labs/2_correspondence_problem/\nspecifically `Geometric normalization` part.",
    "2288961": "Thanks a lot"
  },
  "source": "meta"
}