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Fly6 Video Compression: Blur to Sharpen?

So I stuck a snippet of ordinary “transparent” (it’s actually translucent) adhesive tape across the top of the Cycliq Fly6 camera lens:

Cycliq Fly6 Camera - blur tape

Cycliq Fly6 Camera – blur tape

That smoothly blurs the top third of the frame:

Fly6 - Tape-blurred frame

Fly6 – Tape-blurred frame

The motivation for using translucent tape: it should maintain roughly the same brightness and color balance across the whole image. Opaque tape would burn out the remaining image as the camera desperately tries to maintain an average gray level.

Fast-forwarding VLC with the video stopped forces it to display the inter-frame compression blocks spanning several seconds of video:

Fly6 - Forced compression artifacts

Fly6 – Forced compression artifacts

The upper third of the frame has big, simple blocks that pegged the files at a uniform 475 MB per ten minute file, somewhat lower than the un-blurred 500 to 700 MB. So the compression definitely isn’t working nearly as hard.

I hoped that simplifying the uninteresting part of the image would leave more bits for license plates and other interesting details, which might be the case. New York has two main licence plate color schemes (the obsolete high-contrast blue-on-white and the current low-contrast blue-on-orange “Empire Gold”) and both the Fly6 and the Sony AS30V cameras do much better with white plates in full sun.

Some samples at full size:

Fly6 - License Plates

Fly6 – License Plates

Those were chosen based on:

  • Similar range / angle: just over the center line
  • Same-size crop box: 350 x 197
  • Sun vs. shade

I think those are somewhat sharper than the plates from un-blurred frames, but it’s not like the camera suddenly woke up smarter and started paying attention to the important stuff.

Time for more riding, minus the tape…

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  1. #1 by smellsofbikes on 2015-06-03 - 18:10

    I will be extremely interested in watching this little project develop. We now have two cameras in our lunchtime training group.

    • #2 by Ed on 2015-06-04 - 08:38

      At this point, I think you could modify driver behavior by taping a small cardboard box to your helmet… everybody recognizes the camera, albeit as a GoPro Hero.

  2. #3 by dithermaster on 2015-06-04 - 13:57

    The AS100 has a new sibling that does 4K

    Also, did you try all of the recording mode to see if some worked better? I’d think 720-60p might have less motion blur than 1080-30p but then again in sunlight they both might be short exposures.

    • #4 by Ed on 2015-06-04 - 15:40

      720-60p might have less motion blur than 1080-30p

      The AS30V can take 1280×720 @ 120 fps, but the resolution after compression just wasn’t there: lovely effect, just not for small details. Now that I’ve had time to study the situation, I’ll give it another try and see how it compares with the Fly6; having more exposures per second would be good.

      I did learn that image stabilization smears the frames beyond recovery. Stable, but useless.

  3. #5 by bonnev659 on 2015-06-09 - 08:43

    thank you for posting this. i live in western ny and looking at a fly 6 for rear cam. in the front i have a virb already…

    • #6 by Ed on 2015-06-09 - 10:33

      If somebody’s going to hassle you, they’ll be close enough to make the license plate readable.

      The Fly6 doesn’t seem to have any awful failings, although the whole MicroSD card interface seems remarkably fragile.

      Also, it looks enough like a really big tail light that I just leave it on the bike; it gets lost in the incredible clutter on the back of the Tour Easy’s seat. Might stand out more on the seat post of an upright bike, though.

      • #7 by bonnev659 on 2015-06-09 - 14:24

        good to know. I am waiting and seeing if I should buy 1 or wait. have a great day