{
  "fetched_at": "2026-10-24T12:19:36Z",
  "source_url": "https://www.kaggle.com/competitions/coins/data",
  "pages": [
    {
      "name": "data-description",
      "content": "The dataset directory consists of 1,100 images of rotated coins in .png format with a transparent background layer.\n\nEach image is of a coin rotated a specific amount.\n\nThe Lincoln head images have the format, \"####_lincoln.png\", where \"####\" corresponds to the index of the image.  The index of the image defines the order of angles in the .txt file that will be submitted.   The Lincoln Memorial tail images have the format, \"####_memorial.png\".",
      "isPublished": false,
      "hasIsPublished": false,
      "postTitle": "",
      "hasPostTitle": false,
      "mimeType": "",
      "hasMimeType": false
    },
    {
      "name": "Description",
      "content": "# Introduction\n\nGiven images of rotated one-cent coins of varying (1) shininess/color, (2) years/mintmarks, and (3) levels of wear, as shown below, your objective is to detect the angle of rotation of each coin from the upright position.\n\nThere are two classes of coins: (1) the US Lincoln head one cent and (2) the US Lincoln memorial (tail) one cent.  It is expected that your algorithm can detect the rotation on both classes.\n\n![Labeled Rotated Lincoln Heads](https://i.imgur.com/3ktjY8C.png)\n\n![Labeled Rotated Memorial](https://i.imgur.com/sl6io3h.png)\n\n# Dataset\n\nThe dataset consists of 568 images of rotated Lincoln heads and 532 images of Lincoln memorials.  All images are in color and have size 750 px by 750 px.  Each image is pre-cropped to only contain the circular coin; however, you may want to crop further to remove the coin edge.\n\n![Rotated Dataset](https://i.imgur.com/6QFt3pM.png)",
      "isPublished": false,
      "hasIsPublished": false,
      "postTitle": "",
      "hasPostTitle": false,
      "mimeType": "",
      "hasMimeType": false
    },
    {
      "name": "Evaluation",
      "content": "The evaluation metric for this competition is the absolute value of the difference between the submitted detected angle and the ground truth angle (fixed for 0-360 wrapping), summed over all the coins.  The lower this aggregated deviation is, the better.\n\n![Clockwise Angle](https://i.imgur.com/dZTUNsm.png)\n\nThe angle should be in degrees rotated clockwise from upright position, as shown above.\n\n## Submission Format\n\nThe submission should be a .csv file where the first column is the name of the png file that is being assessed and the second column is the detected angle of rotation.\n\nThe first line must be a header as follows:\n> Id,Predicted\n\n![Sample CSV](https://i.imgur.com/1ChQRsR.png)",
      "isPublished": false,
      "hasIsPublished": false,
      "postTitle": "",
      "hasPostTitle": false,
      "mimeType": "",
      "hasMimeType": false
    },
    {
      "name": "rules",
      "content": " - Don't cheat!\n - Apply yourself!\n - Have fun!",
      "isPublished": false,
      "hasIsPublished": false,
      "postTitle": "",
      "hasPostTitle": false,
      "mimeType": "",
      "hasMimeType": false
    }
  ]
}