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I am working on a research project that involves machine vision. The camera we are using implements infinite focus - I have been informed that this can affect the accuracy of computer vision algorithms, why is this?

At the moment we are implementing ORB for feature matching, out of a total of 175 possible detection events 10 of those appear to be missed due to the object not being clearly focused - but it was my understanding that the point of infinity focus was that everything between the lens and "infinity" would be in acceptable focus?

Is there any other effect of infinity focus that could account for this?

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"Infinity focus" refers to the Hyperfocal Distance of the camera's lens. This is the distance beyond which all objects will appear acceptably focused.

Therefore, if your objects come closer (to the camera) than its hyperfocal distance they will appear blured and detection of sharp features such as corners will become more challenging.

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  • $\begingroup$ Thanks for your answer, would you know of any further reading about the subject (for my own knowledge and for referencing). $\endgroup$ – Colin747 Jun 22 '15 at 8:56
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    $\begingroup$ Thank you, glad to hear this response was helpful. Regarding the hyperfocal distance and image formation in general, any good introductory book to geometrical optics would provide the basic background (en.wikipedia.org/wiki/Geometrical_optics). For DIP, you might want to check: springer.com/us/book/9783642049491 .Other than this, image processing books usually contain good and brief introductory chapters to image formation and representation. (For example Gonzalez' Digital Image Processing). $\endgroup$ – A_A Jun 22 '15 at 9:15
  • $\begingroup$ Thanks again for the help! I'll check out your suggested reading. $\endgroup$ – Colin747 Jun 22 '15 at 9:18

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