{
  "id": 454227,
  "title": "img file pixel value",
  "url": "/competitions/blood-vessel-segmentation/discussion/454227",
  "author_name": "",
  "post_date": "2023-11-09T13:24:44.051320100Z",
  "votes": 2,
  "comment_count": 3,
  "views": 0,
  "content": "<p>I just print img file array, and I can find pixel value is more than 255, even 20000. <br>\nWhat is maximum value pixel can take?<br>\nAnd why it is over 255?</p>",
  "messages": [
    {
      "id": "2518653",
      "postDate": "11/09/2023 13:24:44",
      "content": "<p>I just print img file array, and I can find pixel value is more than 255, even 20000. <br>\nWhat is maximum value pixel can take?<br>\nAnd why it is over 255?</p>",
      "rawMarkdown": "I just print img file array, and I can find pixel value is more than 255, even 20000. \nWhat is maximum value pixel can take?\nAnd why it is over 255?",
      "votes": null
    },
    {
      "id": "2519372",
      "postDate": "11/10/2023 00:43:07",
      "content": "<p>The images are 16 bit grayscale. They can hold around 65,000 values.</p>\n<p>255 is the maximum value for 8 bit .. which is the maximum number of grayscale values that normal video adaptors can display.</p>\n<p>You can't visualize all the variations in these images without a special video card and monitor, which is why they're always normalized down for display.</p>",
      "rawMarkdown": "The images are 16 bit grayscale. They can hold around 65,000 values.\n\n255 is the maximum value for 8 bit .. which is the maximum number of grayscale values that normal video adaptors can display.\n\nYou can't visualize all the variations in these images without a special video card and monitor, which is why they're always normalized down for display.",
      "votes": null
    },
    {
      "id": "2520326",
      "postDate": "11/10/2023 18:40:36",
      "content": "<p>Even if all of them are displayed, I wonder how many shades of gray we can perceive. </p>",
      "rawMarkdown": "Even if all of them are displayed, I wonder how many shades of gray we can perceive.",
      "votes": null
    },
    {
      "id": "2520559",
      "postDate": "11/10/2023 23:57:18",
      "content": "<p>I don't think humans can perceive much more than 8 bits of gray. </p>",
      "rawMarkdown": "I don't think humans can perceive much more than 8 bits of gray.",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 2519372,
      "author_name": "davidbroberts",
      "author_url": "",
      "post_date": "11/10/2023 00:43:07",
      "content": "<p>The images are 16 bit grayscale. They can hold around 65,000 values.</p>\n<p>255 is the maximum value for 8 bit .. which is the maximum number of grayscale values that normal video adaptors can display.</p>\n<p>You can't visualize all the variations in these images without a special video card and monitor, which is why they're always normalized down for display.</p>",
      "votes": null,
      "replies": [
        {
          "id": 2520326,
          "author_name": "gunesevitan",
          "author_url": "",
          "post_date": "11/10/2023 18:40:36",
          "content": "<p>Even if all of them are displayed, I wonder how many shades of gray we can perceive. </p>",
          "votes": null,
          "replies": [
            {
              "id": 2520559,
              "author_name": "davidbroberts",
              "author_url": "",
              "post_date": "11/10/2023 23:57:18",
              "content": "<p>I don't think humans can perceive much more than 8 bits of gray. </p>",
              "votes": null,
              "replies": []
            }
          ]
        }
      ]
    }
  ],
  "raw_markdown_by_id": {
    "2518653": "I just print img file array, and I can find pixel value is more than 255, even 20000. \nWhat is maximum value pixel can take?\nAnd why it is over 255?",
    "2519372": "The images are 16 bit grayscale. They can hold around 65,000 values.\n\n255 is the maximum value for 8 bit .. which is the maximum number of grayscale values that normal video adaptors can display.\n\nYou can't visualize all the variations in these images without a special video card and monitor, which is why they're always normalized down for display.",
    "2520326": "Even if all of them are displayed, I wonder how many shades of gray we can perceive.",
    "2520559": "I don't think humans can perceive much more than 8 bits of gray."
  },
  "source": "meta"
}