{
  "id": 48344,
  "title": "Does the metadata leak any info?...",
  "url": "/competitions/sp-society-camera-model-identification/discussion/48344",
  "author_name": "Andrés Miguel Torrubia Sáez",
  "post_date": "2018-01-26T13:16:08.574000",
  "votes": 4,
  "comment_count": 0,
  "views": 0,
  "content": "<p>Although the EXIF data had been stripped off the test TIF files, I was curious to see if any of the metadata revealed anything. Running <code>identify -verbose ...</code> on the test files still shows some fields. Among those, there's date of creation and modification:</p>\n\n<pre><code>$ identify -verbose test/img_ff225ec_manip.tif | grep date\n    date:create: 2018-01-19T13:13:26+01:00\n    date:modify: 2017-12-19T23:24:24+01:00\n</code></pre>\n\n<p>Of those, <code>date:modify</code> shows a decent range between images. I checked to see if there's some correlation between <code>date:modify</code> and camera type; the hypothesis being that these may have been processed sequentially.</p>\n\n<p>So I stacked together the predictions of my best sub and <code>date:modify</code> times, ordered by the later:</p>\n\n<pre><code>img_d026be5_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\nimg_e2c0574_unalt.tif  2017-12-19T23:25:52+01:00            Motorola-X\nimg_f4d822b_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\nimg_bcf904a_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\nimg_95b66da_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\nimg_ee058bd_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\nimg_b7c9084_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\nimg_67faf71_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\nimg_cbf8578_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\nimg_6580fad_unalt.tif  2017-12-19T23:25:52+01:00              HTC-1-M7\nimg_35ff702_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\nimg_fa9bc92_unalt.tif  2017-12-19T23:25:52+01:00      Motorola-Nexus-6\nimg_d5f1cdb_unalt.tif  2017-12-19T23:25:54+01:00           LG-Nexus-5x\nimg_a16aecd_unalt.tif  2017-12-19T23:25:54+01:00      Motorola-Nexus-6\nimg_b2e6733_unalt.tif  2017-12-19T23:25:54+01:00     Samsung-Galaxy-S4\nimg_8214951_unalt.tif  2017-12-19T23:25:54+01:00            Motorola-X\nimg_57a7a82_unalt.tif  2017-12-19T23:25:54+01:00            Motorola-X\nimg_e055b37_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\nimg_b4ea8ee_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\nimg_ced5c14_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\nimg_f1d0b0d_unalt.tif  2017-12-19T23:25:54+01:00      Motorola-Nexus-6\nimg_47229e1_unalt.tif  2017-12-19T23:25:54+01:00              HTC-1-M7\nimg_9fb1b20_unalt.tif  2017-12-19T23:25:54+01:00             iPhone-4s\nimg_d28252f_unalt.tif  2017-12-19T23:25:54+01:00             iPhone-4s\nimg_2b4e0b1_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\nimg_a8c9a98_unalt.tif  2017-12-19T23:25:54+01:00              HTC-1-M7\nimg_4e05d04_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\nimg_0211120_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\nimg_f1aca0c_unalt.tif  2017-12-19T23:25:56+01:00             iPhone-4s\nimg_9e07b25_unalt.tif  2017-12-19T23:25:56+01:00              iPhone-6\n</code></pre>\n\n<p>So it looks there's no correlation, except that the <code>unalt</code> was processed after <code>manip</code>.</p>",
  "messages": [
    {
      "id": 274368,
      "postDate": "2018-01-26T13:16:08.573Z",
      "content": "<p>Although the EXIF data had been stripped off the test TIF files, I was curious to see if any of the metadata revealed anything. Running <code>identify -verbose ...</code> on the test files still shows some fields. Among those, there's date of creation and modification:</p>\n\n<pre><code>$ identify -verbose test/img_ff225ec_manip.tif | grep date\n    date:create: 2018-01-19T13:13:26+01:00\n    date:modify: 2017-12-19T23:24:24+01:00\n</code></pre>\n\n<p>Of those, <code>date:modify</code> shows a decent range between images. I checked to see if there's some correlation between <code>date:modify</code> and camera type; the hypothesis being that these may have been processed sequentially.</p>\n\n<p>So I stacked together the predictions of my best sub and <code>date:modify</code> times, ordered by the later:</p>\n\n<pre><code>img_d026be5_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\nimg_e2c0574_unalt.tif  2017-12-19T23:25:52+01:00            Motorola-X\nimg_f4d822b_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\nimg_bcf904a_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\nimg_95b66da_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\nimg_ee058bd_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\nimg_b7c9084_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\nimg_67faf71_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\nimg_cbf8578_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\nimg_6580fad_unalt.tif  2017-12-19T23:25:52+01:00              HTC-1-M7\nimg_35ff702_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\nimg_fa9bc92_unalt.tif  2017-12-19T23:25:52+01:00      Motorola-Nexus-6\nimg_d5f1cdb_unalt.tif  2017-12-19T23:25:54+01:00           LG-Nexus-5x\nimg_a16aecd_unalt.tif  2017-12-19T23:25:54+01:00      Motorola-Nexus-6\nimg_b2e6733_unalt.tif  2017-12-19T23:25:54+01:00     Samsung-Galaxy-S4\nimg_8214951_unalt.tif  2017-12-19T23:25:54+01:00            Motorola-X\nimg_57a7a82_unalt.tif  2017-12-19T23:25:54+01:00            Motorola-X\nimg_e055b37_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\nimg_b4ea8ee_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\nimg_ced5c14_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\nimg_f1d0b0d_unalt.tif  2017-12-19T23:25:54+01:00      Motorola-Nexus-6\nimg_47229e1_unalt.tif  2017-12-19T23:25:54+01:00              HTC-1-M7\nimg_9fb1b20_unalt.tif  2017-12-19T23:25:54+01:00             iPhone-4s\nimg_d28252f_unalt.tif  2017-12-19T23:25:54+01:00             iPhone-4s\nimg_2b4e0b1_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\nimg_a8c9a98_unalt.tif  2017-12-19T23:25:54+01:00              HTC-1-M7\nimg_4e05d04_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\nimg_0211120_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\nimg_f1aca0c_unalt.tif  2017-12-19T23:25:56+01:00             iPhone-4s\nimg_9e07b25_unalt.tif  2017-12-19T23:25:56+01:00              iPhone-6\n</code></pre>\n\n<p>So it looks there's no correlation, except that the <code>unalt</code> was processed after <code>manip</code>.</p>",
      "rawMarkdown": "Although the EXIF data had been stripped off the test TIF files, I was curious to see if any of the metadata revealed anything. Running `identify -verbose ... ` on the test files still shows some fields. Among those, there's date of creation and modification:\n\n    $ identify -verbose test/img_ff225ec_manip.tif | grep date\n        date:create: 2018-01-19T13:13:26+01:00\n        date:modify: 2017-12-19T23:24:24+01:00\n\nOf those, `date:modify` shows a decent range between images. I checked to see if there's some correlation between `date:modify` and camera type; the hypothesis being that these may have been processed sequentially.\n\nSo I stacked together the predictions of my best sub and `date:modify` times, ordered by the later:\n\n    img_d026be5_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\n    img_e2c0574_unalt.tif  2017-12-19T23:25:52+01:00            Motorola-X\n    img_f4d822b_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\n    img_bcf904a_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\n    img_95b66da_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\n    img_ee058bd_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\n    img_b7c9084_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\n    img_67faf71_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\n    img_cbf8578_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\n    img_6580fad_unalt.tif  2017-12-19T23:25:52+01:00              HTC-1-M7\n    img_35ff702_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\n    img_fa9bc92_unalt.tif  2017-12-19T23:25:52+01:00      Motorola-Nexus-6\n    img_d5f1cdb_unalt.tif  2017-12-19T23:25:54+01:00           LG-Nexus-5x\n    img_a16aecd_unalt.tif  2017-12-19T23:25:54+01:00      Motorola-Nexus-6\n    img_b2e6733_unalt.tif  2017-12-19T23:25:54+01:00     Samsung-Galaxy-S4\n    img_8214951_unalt.tif  2017-12-19T23:25:54+01:00            Motorola-X\n    img_57a7a82_unalt.tif  2017-12-19T23:25:54+01:00            Motorola-X\n    img_e055b37_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\n    img_b4ea8ee_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\n    img_ced5c14_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\n    img_f1d0b0d_unalt.tif  2017-12-19T23:25:54+01:00      Motorola-Nexus-6\n    img_47229e1_unalt.tif  2017-12-19T23:25:54+01:00              HTC-1-M7\n    img_9fb1b20_unalt.tif  2017-12-19T23:25:54+01:00             iPhone-4s\n    img_d28252f_unalt.tif  2017-12-19T23:25:54+01:00             iPhone-4s\n    img_2b4e0b1_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\n    img_a8c9a98_unalt.tif  2017-12-19T23:25:54+01:00              HTC-1-M7\n    img_4e05d04_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\n    img_0211120_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\n    img_f1aca0c_unalt.tif  2017-12-19T23:25:56+01:00             iPhone-4s\n    img_9e07b25_unalt.tif  2017-12-19T23:25:56+01:00              iPhone-6\n\nSo it looks there's no correlation, except that the `unalt` was processed after `manip`.",
      "votes": 4
    }
  ],
  "comments": [],
  "raw_markdown_by_id": {
    "274368": "Although the EXIF data had been stripped off the test TIF files, I was curious to see if any of the metadata revealed anything. Running `identify -verbose ... ` on the test files still shows some fields. Among those, there's date of creation and modification:\n\n    $ identify -verbose test/img_ff225ec_manip.tif | grep date\n        date:create: 2018-01-19T13:13:26+01:00\n        date:modify: 2017-12-19T23:24:24+01:00\n\nOf those, `date:modify` shows a decent range between images. I checked to see if there's some correlation between `date:modify` and camera type; the hypothesis being that these may have been processed sequentially.\n\nSo I stacked together the predictions of my best sub and `date:modify` times, ordered by the later:\n\n    img_d026be5_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\n    img_e2c0574_unalt.tif  2017-12-19T23:25:52+01:00            Motorola-X\n    img_f4d822b_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\n    img_bcf904a_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\n    img_95b66da_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\n    img_ee058bd_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\n    img_b7c9084_unalt.tif  2017-12-19T23:25:52+01:00           LG-Nexus-5x\n    img_67faf71_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\n    img_cbf8578_unalt.tif  2017-12-19T23:25:52+01:00              iPhone-6\n    img_6580fad_unalt.tif  2017-12-19T23:25:52+01:00              HTC-1-M7\n    img_35ff702_unalt.tif  2017-12-19T23:25:52+01:00     Samsung-Galaxy-S4\n    img_fa9bc92_unalt.tif  2017-12-19T23:25:52+01:00      Motorola-Nexus-6\n    img_d5f1cdb_unalt.tif  2017-12-19T23:25:54+01:00           LG-Nexus-5x\n    img_a16aecd_unalt.tif  2017-12-19T23:25:54+01:00      Motorola-Nexus-6\n    img_b2e6733_unalt.tif  2017-12-19T23:25:54+01:00     Samsung-Galaxy-S4\n    img_8214951_unalt.tif  2017-12-19T23:25:54+01:00            Motorola-X\n    img_57a7a82_unalt.tif  2017-12-19T23:25:54+01:00            Motorola-X\n    img_e055b37_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\n    img_b4ea8ee_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\n    img_ced5c14_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\n    img_f1d0b0d_unalt.tif  2017-12-19T23:25:54+01:00      Motorola-Nexus-6\n    img_47229e1_unalt.tif  2017-12-19T23:25:54+01:00              HTC-1-M7\n    img_9fb1b20_unalt.tif  2017-12-19T23:25:54+01:00             iPhone-4s\n    img_d28252f_unalt.tif  2017-12-19T23:25:54+01:00             iPhone-4s\n    img_2b4e0b1_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\n    img_a8c9a98_unalt.tif  2017-12-19T23:25:54+01:00              HTC-1-M7\n    img_4e05d04_unalt.tif  2017-12-19T23:25:54+01:00   Motorola-Droid-Maxx\n    img_0211120_unalt.tif  2017-12-19T23:25:54+01:00  Samsung-Galaxy-Note3\n    img_f1aca0c_unalt.tif  2017-12-19T23:25:56+01:00             iPhone-4s\n    img_9e07b25_unalt.tif  2017-12-19T23:25:56+01:00              iPhone-6\n\nSo it looks there's no correlation, except that the `unalt` was processed after `manip`."
  }
}