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I work on image processing using images from webcams. It's connected via USB and I get "live" images by:

Dynamic[Refresh[CurrentImage[], UpdateInterval->5]]

but the UpdateInterval option doesn't affect the frequency of image updating. How to make Dynamic get images from webcams with a specific time interval? There is ImageCapture function with a FrameRate option and it works fine, but functionality of ImageCapturelooks excessive for me (I only need an image).

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  • $\begingroup$ Related conversation in site's chat. $\endgroup$
    – Silvia
    Commented Nov 28, 2019 at 17:21
  • $\begingroup$ This appears to happen because CurrentImage has its own internal Refresh to allow for Dynamic[CurrentImage[]] shorthand. The discussion in chat linked above has a workable solution that I have now used in production (ie, an art exhibition) $\endgroup$
    – Carl Lange
    Commented Nov 28, 2019 at 18:14

2 Answers 2

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The easiest way to solve this is by setting the framerate on the device.

dev = First@FindDevices["Camera"]

DeviceConfigure[dev, "FrameRate" -> 1/5]

Dynamic[CurrentImage[]]
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Just came across the same problem in my code. Here is a workaround:

capt[dt_] := Block[{},
  Pause[dt];
  CurrentImage[]
  ]


Dynamic[capt[.1]]

Unfortunately, the drawback is that for large sleep times (>0.5seconds) it really slows down the Mathematica notebook (I think it's a side effect of Pause)

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