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computational_photography_talk [2010-10-27 16:55] – created davegriffiths | computational_photography_talk [2010-11-12 08:10] – davegriffiths | ||
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- | ==odd things that people do with cameras== | + | 11 November presentation at Aalto University on computer |
- | or | + | |
- | ==machine vision== | + | |
- | or | + | |
- | ==understanding images with a computer== | + | |
- | as a computational photographer, | + | Link to presentation: |
- | * everything you do with digital photography derives from this field, eg | + | Videos: |
- | - digital filtering (from ccd de-bayer algorithms upwards) | + | |
- | - auto focus/ | + | |
- | - face finding/ | + | |
- | * a lot of the future will come from this field | + | * particle filter: [[http:// |
- | - object | + | * eigenface animation: [[http:// |
- | | + | * expression |
- | | + | * 3d morphable face model: [[http:// |
- | (will talk of some of this later) | + | * slam augmented reality: [[http:// |
- | | + | Code: |
- | - lots going on | + | |
- | - much to be discovered | + | |
- | - lots of _hard_ problems to be solved | + | |
- | but not hard to get fun things happening yourself | + | Links: |
- | * as an artist you can cherry pick the easy/fun bits or use good quality prewritten libraries | + | * opencv: [[http:// |
+ | * artoolkit: [[http:// | ||
+ | * nasa vision workbench: [[http:// | ||
- | what computer vision is not: | ||
- | * anything to do with neuroscience (a lot of people think it is) | ||
- | * it's all statistics! | ||
- | |||
- | ==example 1 : separate moving and still things in a sequence of images== | ||
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- | * frame differencing | ||
- | * finding overall direction of movement | ||
- | |||
- | * this actually works, is robust to lighting changes, camera wobble etc | ||
- | * results in useable data | ||
- | * (all eyetoy games use this technique) | ||
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- | why it works - temporal memory is short and well defined | ||
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- | ==example 2 : seperate background from person in scene== | ||
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- | * subtract current image from reference image without persion | ||
- | * works! (for a few minutes) | ||
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- | lighting changes, camera auto settings, passing cars... all conspire against us. | ||
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- | doesn' | ||
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- | _very hard problem_ seen much time and money sunk into solving this without result | ||
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- | ==example 3 : faces== | ||
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- | faces are great for computational photographers because: | ||
- | * most images have a few in them | ||
- | * we all have one | ||
- | * we are particually attuned to understanding them | ||
- | * a lot of research has been done on this, a lot we can build on as artists | ||
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- | actually several problems | ||
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- | - recognising what is a face in an image (face finding) | ||
- | - recognising who is who in an image (face recognition) | ||
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- | * face finding: haar cascades, wavelets, example images | ||
- | * face recognition: | ||
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- | ==eigenfaces== | ||
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- | * extracting information on age, gender, ethnicity, expression from a face image | ||
- | * modifying this information - changing a faces age, gender .... | ||
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- | scary examples | ||
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- | ==augmented reality== | ||
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- | * marker pose estimation | ||
- | * rendering 3D objects in the real world | ||
- | * yeah yeah but you need a marker... | ||
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- | ==SLAM: simultaneous location and mapping== | ||
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- | * gradually building a model of the scene from a camera in realtime | ||
- | * example video | ||
- | * no markers needed | ||
- | * lots of cool things will come from this in future | ||
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- | ==3D cameras== | ||
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- | * RGB + depth per pixel | ||
- | * microsoft project natal | ||
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- | solves a lot of problems, creates some interesting new ones | ||
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- | how? | ||
- | * stereo cameras | ||
- | * structured light | ||
- | * wavefront analysis | ||
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- | ==where do I get some of this stuff?== | ||
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- | * opencv | ||
- | * artoolkit | ||
- | * nasa image processing library | ||
- | * lots of research code is out there and waiting for artistic (mis)use! | ||
- | * they may actually help you in between publishing papers | ||
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- | tips | ||
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- | * think like a photographer - how can I set the scene to suit what I am trying to do, lights, camera position etc etc are as important as finding the right algorithm. |