{"id":1044,"date":"2018-04-11T04:31:03","date_gmt":"2018-04-11T03:31:03","guid":{"rendered":"https:\/\/dmunkes.de\/WP\/?p=74"},"modified":"2018-04-19T22:11:41","modified_gmt":"2018-04-19T21:11:41","slug":"2dor3d","status":"publish","type":"post","link":"https:\/\/dmunkes.de\/WP\/2dor3d\/?lang=en","title":{"rendered":"When to use 2D or 3D Data for recognition"},"content":{"rendered":"

When to use 2D or 3D Data for recognition<\/h1><\/h1><\/div>
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Ing. Buero Dieter Munkes News   \u2022   June 2, 2016<\/p>\n<\/div>

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3D scan, laser welding<\/p>\n<\/div>

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2<\/span> optical technologies are actualy used for inspection or recognition. There is photo camera and the  3D measurement in different ways.<\/p>\n

First a few words about photo camera.<\/h3>\n

Today I use TPC\/IP camera for easy connectivity. USB3 would be ok to.On market you get fooded by cheap cameras.<\/p>\n

Let\u00b4s compare a little.<\/p>\n

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What are the differences:<\/p>\n

The industrial Version have:<\/p>\n

    \n
  • Bigger lenses = more light , less deeps of focus!<\/li>\n
  • Bigger amount of possible lenses<\/li>\n
  • Flash trigger output<\/li>\n
  • very short exposure times (32usek)<\/li>\n
  • Global shutter<\/li>\n
  • Monochrome Sensors to avoid Bayer interpolation.<\/li>\n<\/ul>\n

    The cheap ones have:<\/p>\n

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    • very small sensors and lenses = less light but deeps fokus is fine<\/li>\n
    • mostly fixed lens<\/li>\n
    • no flash<\/li>\n
    • rolling shutter and with this unusable on moving objects.<\/li>\n
    • normaly color sensor<\/li>\n<\/ul>\n

      Extracting the details from the picture you needed for your propose depends on ilumination.<\/p>\n

      This is the key to success. You can not compensate any wrong lightning by software.<\/p>\n

      Mostly I need to switch different lights in different positions to get a picture for every parameter i want to extract.<\/p>\n

      (You use both eyes and\/or move your head to do the same)<\/p>\n

       <\/p>\n

      Let\u00b4s go to 3D<\/h3>\n

       <\/p>\n

      I worked with different kind of sensors:<\/p>\n

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      • Time of flight of a scanned Laser (slow)<\/li>\n
      • Time of flight camera like sensor (low resolution)<\/li>\n
      • Reflected Laserline under constant angle. (medium fast)<\/li>\n
      • projected pattern (never tried this)<\/li>\n
      • Dual camera like our eyes (never tried this )<\/li>\n<\/ul>\n

        All of this methodes have different ranges and accuacy.<\/p>\n

        But common is they are all more expensive than an photo camera.<\/p>\n

        From view of software, in 3D data it is more easy when to find edges , objects.<\/p>\n

        There is no foreign light no reflections. (Laser systems)<\/p>\n

        But, no colors, nothing like photo flash.<\/p>\n

         <\/p>\n

        Now my selection of method.<\/p>\n

        2D camera<\/p>\n

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        • low budget<\/li>\n
        • low requirement<\/li>\n
        • fast<\/li>\n
        • recognition not measure<\/li>\n<\/ul>\n

           <\/p>\n

          3D sensor<\/p>\n

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          • control robotics handle 3d results<\/li>\n
          • measure deeps or size or distance<\/li>\n<\/ul>\n

            You can measure with 2D camera too but mostly need  telecentric components. This easily explode your budget.<\/p>\n

            Sometimes i need both when it comes to measure and color.<\/p>\n

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            <\/div><\/div><\/div><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"

            Two optical technologies are actualy used for inspection or recognition. The older is photo camera and the 3D measurement in different ways.<\/p>\n","protected":false},"author":1,"featured_media":1195,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[44,45,43,47,48,46],"class_list":["post-1044","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-latest-articles","tag-2d","tag-3d","tag-bildverarbeitung","tag-coordination","tag-inspection","tag-robot"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t