Adjust Camera in Hyperion - Color - Help required

  • Dear Friends,

    I try to setup Hyperion with my Pi Cam, but I have issues calibrating. I took a picture to show the problem on a white screen.

    Due to capturing the screen image via camera and the viewing angle the camera detects a certain "gradient" where it should be white.

    I mean I can related why this happens but I dont know if I can compensate it.


    Is there any option in hyperion how to correct for this or any other suggestions? Is the Camera the problem?


    Any help would be appreciated.

  • I had similar issues and found that trying to fine tune a webcam for Hyperion was difficult.


    Try here to see how to change the camera settings via v4l2 - you will have options to set exposure, brightness, saturation and such. Some items have to be disabled to enable others.


    The main issue I had was trying to remove the camera flicker. The lower the exposure compensation the better the colour match, but this increased flicker.

  • There is already been topics about adding a real camera as capturing device to Hyperion.NG


    the main problem is the refresh rate of the camera and tv don't match, the flickering that you see is a result of that.

    See it like this, its blinking the eyes at excact the same moment that the image will fade, thats impossible.

    the flickering is the black and colourfull images of the camera which is taking (screenshots) from your live image of tv.

    Your tv s also displaying images with a refreshrate...


    when reducing exposure on camera thats only make the intervals shorter ( say.. squinting the eyes) so less light will come into the image but because of that shorter interval thus the "screenshot" has more flickering in the image.

    so, no with Hyperion.NG i doubt it you will get good results, and the camera has to be exact straight before the tv to work.


    note; the (web)camera in fact is just a photo camera which makes a lot of images in one sec ( like 25Frames/sec) because your tv is capable of for instance 4K or 1080p with 50/60 Hertz those two will never synchronize.

    its possible but then you need software with algoryhtm that filters this out/ synchronizes.

    software that had done this is Ambivision with special multidegrees camera.

  • I had decent results with the camera position which was sat on top of my rear-right surround speaker. The distance was about 3.2 metres from a 65" TV. I used the trapezoid settings but also cropped the image in by 120 pixels all around so that the capture window had as much of the screen in as possible. Size decimation was 1 for better resolution of the capture, but low resolution setting (320 x 240 I think).


    This seems to work well, I just struggle with highlights being blown out by the camera so the capture is more white than a colour.


    So if I could get a webcam that has a capture rate of 50 or 60 Hz to match the screen that would work?

  • Lets see what I can do if I can find a decent camera


    I also experimented with it, it sure would be much easyer to go the "cameraroute" and evade all kind of HDMI problems that you can have with directly live feed.


    the only thing is the Raspi is not that strong to run a OS, run hyperion, steer the lights. and render the image thats coming in.

    all that processes using a lot of recource from your PI, even the newest one PI4 2GB >> which don't run Hyperion good.

    if that would be the case that would be awesome

  • I'm also wondering if I could re-purpose an old smartphone as the webcam.

    that is also a good idea, maybe you can use the UCB-C connection for that to transport the video. USB-C is also for transport of data upto 6 GB/sec.




    if you really want to go this route, look for our diehard member AmbiMod , he's really going down under in things and makes all kind of manuals to install all kind of software and make hardware work on Hyperion and the Raspi.

    https://ambimod.jimdofree.com/2017/07/07/tuto-faire-du-hue-hue-like-avec-une-caméra-un-raspberry-et-hypérion/



    hence, he is french and a little crazy so use the translating ;)

  • Sorry to hijack, quick question:

    How do I set up the camera areas like you did?

    I am using a USB camera and I only see the option to crop pixels from the sides, no option to adjust it like you did in the picture.

    Sorry, do you mean adapting the leds to the TV boundaries that are not perfectly horizontal/vertical ?


    Please find my screenshot in german attached. It's in LED Hardware in expanded section. You can specify the locations of all 4 corners. Honestly I did search a while myself to find it :D

  • piperion did you manage the calibrating process? If so, how did you do? v4l2-ctrl script at startup?

    Nope it seems that the picam it self is not so great. Tested with droidcam from my phone brought a better color result however, had a noticable delay. For my PS I now use a 20 € hdmi splitter/grabbed from china, works like charm. However I need to use netflix etc on the PS rather than the smart TV. It delivers 1080p grabber and loops 2160p 60hz through... Good enough...

  • Yes, i tested with an old webcam on a movie night, seem better than pi camera for that too. Didn't notice the delay.


    I used chinese splitter/grabber and worked like a charm too, but with time splitter and/or grabber randomly stop.


    Now i have an HDR TV + PS5 and i think i will build my setup with the webcam (wich need some calibrating too) instead of degrading the TV signal.


    Thank you

  • Talking about the color picture using an old oneplus as a webcam yieldsna good result. I use the grabber with my PS5 too. However if you have a webcam that works as good as my oneplus image-wise then this should be your go to solution. Since it is universal and not dependent on the output device/resolution and enables >60hz frame rates (to not slow down the ps5/TV rate)

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