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maintaing same brightness throughout video

Posted: Thu Nov 29, 2018 4:46 am
by krishnakumar77777
Hi,
How can i keep the brightness of video same throughout the video where the openmv cam will be moved in all x,y and z direction seperately in outdoor?

Re: maintaing same brightness throughout video

Posted: Thu Nov 29, 2018 11:08 am
by iabdalkader
krishnakumar77777 wrote:
Thu Nov 29, 2018 4:46 am
Hi,
How can i keep the brightness of video same throughout the video where the openmv cam will be moved in all x,y and z direction seperately in outdoor?
Disable auto-functions ?

http://docs.openmv.io/search.html?q=set ... ea=default

Re: maintaing same brightness throughout video

Posted: Thu Nov 29, 2018 11:17 pm
by krishnakumar77777
By disabling all these,can i get the same amount of light even when the openmv moves?I explain my scenario. I want to detect lemon fruit in the plant in outdoor by making the scanning using movement of openmv cam on a slide. Can disabling helps me out?

Re: maintaing same brightness throughout video

Posted: Fri Nov 30, 2018 10:43 am
by iabdalkader
krishnakumar77777 wrote:
Thu Nov 29, 2018 11:17 pm
By disabling all these,can i get the same amount of light even when the openmv moves?I explain my scenario. I want to detect lemon fruit in the plant in outdoor by making the scanning using movement of openmv cam on a slide. Can disabling helps me out?
Yes, but you should let them run for a while to set some initial values, try this:

Code: Select all

sensor.skip_frames(time=1000)
sensor.set_auto_gain(False)
sensor.set_auto_exposure(False)

Re: maintaing same brightness throughout video

Posted: Sat Dec 08, 2018 3:38 am
by krishnakumar77777
what will the polarizer filter do?

Re: maintaing same brightness throughout video

Posted: Sat Dec 08, 2018 7:38 pm
by iabdalkader
krishnakumar77777 wrote:
Sat Dec 08, 2018 3:38 am
what will the polarizer filter do?
As I understand it, it attenuates a certain wavelength so you can use it in direct sunlight, it's like sun glasses. See the comparison photos in the product description:

https://openmv.io/collections/products/ ... ing-filter

I don't think that's what you need. It should be enough to disable the auto-functions like I mentioned.

Re: maintaing same brightness throughout video

Posted: Mon Dec 10, 2018 9:56 pm
by jisheng
I think you are talking about making each frame have the same light even if the light outdoors changes. do i understand correctly?

Re: maintaing same brightness throughout video

Posted: Mon Dec 17, 2018 5:17 am
by krishnakumar77777
yes jisheng. you got it correctly. can you help me?

Re: maintaing same brightness throughout video

Posted: Tue Dec 18, 2018 11:16 am
by kwagyeman
Um, to do this you'd want to change the sensor exposure value based on the value returned by get_stats(). So, see the sensor control scripts and adjust the exposure up or down depending on if you're above or below some lightness threshold.

Re: maintaing same brightness throughout video

Posted: Fri Dec 21, 2018 10:36 am
by krishnakumar77777
hi,
lightness threshold means?what i want to use from get-statitics function? L or A or B? median or mean or standard deviation? help please

Re: maintaing same brightness throughout video

Posted: Fri Dec 21, 2018 11:06 am
by kwagyeman
Hi, use the median of the L channel and adjust the the automatic exposure accordingly.

Re: maintaing same brightness throughout video

Posted: Fri Dec 21, 2018 8:04 pm
by krishnakumar77777
Hi,
I am also using the polarizing filter which i bought from you.

Re: maintaing same brightness throughout video

Posted: Mon Jan 07, 2019 10:53 pm
by krishnakumar77777
Hi,
i need to detect white colored object within 3-5cm under sunlight using an color sensor. Which sensor best fit for this?

Re: maintaing same brightness throughout video

Posted: Mon Jan 07, 2019 11:59 pm
by kwagyeman
Hi, the OV7725?