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touch tap detection slow if I touch the same position

asked 2018-07-21 10:33:18 -0600

yongseokok gravatar image

Hi!

I tried to use setMouseCallback() to detect touch operation on the touch screen by using C++. It works fine to detect touch with position information. But when I tried to touch the same position, It seems slowing touch detection event very much. If I touch the different position, it responds quickly. Is there any any to avoid this situation ?

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just curious, what kind of device / os would that be ?

berak gravatar imageberak ( 2018-07-21 10:36:50 -0600 )edit

I am using windows 10 desktop with visual studio 2017.

yongseokok gravatar imageyongseokok ( 2018-07-22 20:46:01 -0600 )edit

i am using opencv for my project not only for image processing but also for GUI with touch screen. There are cases to increase or decrease values on GUI button icon which means tap on same area on the touch screen repeatedly. To check the situation, I use mouse to click the same position repeatedly and move a slightly different position repeatedly on the button icon. When I click slightly different position but in the icon area, it works fine(no delay). But if I click the same position repeatedly, there are remarkable delay to respond.

yongseokok gravatar imageyongseokok ( 2018-07-22 20:53:50 -0600 )edit

In my honoust opinion, if you want to detect touch, you do not need OpenCV, unless you want to film someone and see where they are tapping on another screen? Your decision I am using opencv for my project not only for image processing but also for GUI with touch screen is simply wrong. The simple GUI elements in OpenCV are for debugging, not for building robust interfaces.

StevenPuttemans gravatar imageStevenPuttemans ( 2018-07-23 07:25:33 -0600 )edit

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answered 2018-07-24 20:24:19 -0600

yongseokok gravatar image

I understand what you mentioning. I may use another approach to solve the issue. But in any case, I recommend somebody could watch and fix it when there is change because it is implemented to be used by somebody. If this function is not reliable, it should be noted that the function is not reliable and only for debugging on it's documents. Thanks for your comment.

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setMouseCallback() is for getting an accurate mouse clicked location. There is not a single delay here when using an external mouse, which makes me believe that part of the issue is still at the end of the touch screen capture process, and not in OpenCV.

StevenPuttemans gravatar imageStevenPuttemans ( 2018-07-25 02:32:12 -0600 )edit

Thanks for your update. I will be more happy than any people if mouse function is perfect (yes it's perfect). I will re-check my process but if you have any time, please try to press mouse L button at the same position 3 to 4 times per second for few seconds and watch whether there are any missed detection. I don't want to make waste your time and efforts If you think there is no issue like what I mentioned. So, if you are so sure , I will close this case. I would like to give my thanks to all the members for the opencv projects and your efforts to comments on my issue. Best Regards, YS

yongseokok gravatar imageyongseokok ( 2018-07-26 23:11:39 -0600 )edit

check the OpenCV annotation tool, which I wrote, I can hit the same place over and over again, and if I debug it gets catched every single time.

StevenPuttemans gravatar imageStevenPuttemans ( 2018-07-27 02:37:44 -0600 )edit

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Asked: 2018-07-21 10:33:18 -0600

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Last updated: Jul 24 '18