Taxi changes direction at traffic lights

PC2017

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Night time vids were at 60fps, auto shutter and auto exposure locked to mid-frame. I'll try daytime cycling plate snapping next, but I can't imagine it'd be worse than my Crosstour 4k, which did a good job of capturing daylit number plates - if it is, I'll simply turn off Hypersmooth and go manual/Protune.
Hold it down a min... Are you "snapping" a number plate as a "taken" picture, ie when you spot an idiot you press the photo button? To get a number plate I would retrieve a "still" in post, at 60 fps a freeze frame would produce a good image albeit only tested from daylight footage.

I have image stabilisation I have not heard of hypersmooth etc.
 

PC2017

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and Youtube has squeezed all life out of the quality,
I always aim for 22mb bit rate when exporting for YT. Sometimes, whether or not it still does, but YT does upload the vid as low quality then a few days later it improves, there is a reason for it, I did question that myself once but I can not remember why.
 

guerney

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Hold it down a min... Are you "snapping" a number plate as a "taken" picture, ie when you spot an idiot you press the photo button? To get a number plate I would retrieve a "still" in post, at 60 fps a freeze frame would produce a good image albeit only tested from daylight footage.
I'm grabbing frames from video shot at night.
 
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PC2017

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PC2017

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I'm grabbing frames from video shot at night.
It could be the helmet cam angle then or like you say settings or night recording
 

guerney

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I always aim for 22mb bit rate when exporting for YT. Sometimes, whether or not it still does, but YT does upload the vid as low quality then a few days later it improves, there is a reason for it, I did question that myself once but I can not remember why.
It's network processing, at busy times it takes longer to process to HD and propagate to Youtube steaming server nodes. Some people have recommended 40mb/s data rate, which is mental (albeit for 4k) to ensure that Youtube's compression process doesn't kill as much quality.
 
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guerney

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I got creative with mine, I will pop a pic up in the near future...
I saw some chap on Youtube mount his on a gimbal gaffa taped to his motorbike handlebars. Very fragile things, gimbals, but that would improve night footage without Hypersmooth... and daytime shot footage with Hypersmooth plus gimbal looks freaking awesome, in terms of smoothness - almost as good as Steadicams.
 

guerney

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It could be the helmet cam angle then or like you say settings or night recording
Night footage always looks awful on action cameras, the current ones, unless scenes are brightly lit. I don't care about noise levels, or making a pretty picture - I just want consistent, clearly captured night numberplates. Will keep fiddling with settings...
 
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guerney

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I've set ISO to this cameras's maximum: 6400 and shutter to 1/480th of a second - that should kill most motion blur, but will the images be too noisy to spot numberplates? I'll find out soon-ish, on my next night ride...
 
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matthewslack

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I always intend to shout out the number plate for the audio to catch, but it usually comes out as what the **** **** **** **** **** **** was that?
 
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guerney

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Testing this morning was interrupted by these happenings:


As I spectulated on these forums some months ago, control over shutter speed may well be key to capturing clearer views of vehicle number plates at night (something my cheapo Crosstour 4K lacks) - there is much less motion blur, but oodles more noiose because of such high ISO... but I'm pleased to report that ISO 1600 and shutter at 1/240th of a second, is more often than not, capturing large sections of, or whole number plates - these screengrabs from video don't look cinematic, but that's not what want from a cycling-flight-recorder-in-case-of-horrible-accidents.

When passing fast and close:

50037


When passing by fast (from a brief period of shooting @ISO 800):

50035


Also a fast pass (ISO 1600 again and hereafter)

50038


It appears I can even get some plate info from approaching vehicles, if they're close enough to the beams of my headlights:

50039


I'm not managing to capture 100% of passing numberplates, I'll do a proper calculation at some point, but it's much more often than not.

Well, there you have it - if you own a GoPro Hero 7 Black or similar action camera with full manual control of the same era or newer, it's quite likely that you too can capture number plates while cycling about at night.
 

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PC2017

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gimbal looks freaking awesome
Ikr - first time I saw a cheapo cam(£20) from China I thought wow that's amazing stabilisation until I saw his shadow and a stick like attachment with the cam on, turned out he was using a £300 gimble to test it pml

shout out the number plate
I know I preach diffuse a situation if at all possible, but I often catch myself shouting moron and various other expletives before I calm down, it's instinctive.


I'm not getting 100% of plates,
Vast improvement - I will try & test mine soon
 
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sjpt

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High shutter speed plus using multiple sequential images seems way to get best results.
I don't know what software might help with that; most of the difficult part is probably done in any mpeg encoder.

When our group was working on image processing in the late '70s the police had one particular image (from standard film camera) where they really wanted to get the plate number. We couldn't manage it; maybe someone did in the end and they prosecuted a very surprised truck driver?
 
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guerney

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I will try & test mine soon
If you can get control over ISO and shutter speed, I think your camera is likely capable of doing the same - they just didn't built control over shutter speed into my cheapo Crosstour 4k, I'm pretty sure it could have done this too. Kudos to GoPro for including full manual control over settings, instead of making a camera which pleases just surfer dudes and bras showing off - but there's auto mode for that, which works great in daylight.
 
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guerney

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High shutter speed plus using multiple sequential images seems way to get best results.
I haven't tried taking fast sequential photos (my SD card can't handle it anyway, too slow, but it's fast enough for 4k video, weirdly) - these are still captures from video files. VLC (it's free) has a frame capture button, hit to capture the offending plate while playing back later on. Press "E" to advance one frame at a time, right arrow to skip forwards a bit, left arrow to skip back, "+" to speed up playback, "-" to slow it down... it's the best player out there, and the only one I use.


When our group was working on image processing in the late '70s the police had one particular image (from standard film camera) where they really wanted to get the plate number. We couldn't manage it; maybe someone did in the end and they prosecuted a very surprised truck driver?
Film is far superior, depending on the application and film type of course. Oodles more hidden info. The cops also have some very effective deblurring software, which - if they can be bothered to follow up - could be used to get the plate of the vehicle which killed you cycling. Every cyclist should carry a camera. It's saddening how many news reports of killed cylists contain the words "Police are appealing for witnesses".
 
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sjpt

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Capturing the frames from the movie is straightforward as you say. FFMPEG will probably be more convenient for capturing a batch. (VLC , like many other programs, may well be using ffmpeg underneath?) The difficultly comes with processing the batch. If you could interpret the video direct if might already have encoded the motion vectors.

I used to use VLC, but for various reasons (which I forget) found Media Player Classic (https://mpc-hc.org/) better. I got that as part of Klite codecs; which I installed using Ninite (https://ninite.com/). If you haven't tried Ninite for suggesting and installing software give it a whirl. It's always the first thing I go to with a new PC.
 

guerney

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Capturing the frames from the movie is straightforward as you say. FFMPEG will probably be more convenient for capturing a batch. (VLC , like many other programs, may well be using ffmpeg underneath?) The difficultly comes with processing the batch. If you could interpret the video direct if might already have encoded the motion vectors.
Most (some free) video editing programs will extract a region of the timeline to export all frames, but I'd rather just deal with one or two frames I capture during playback (I'd roughly know where the offending plate was during the recording of a journey), instead of having to deal with hundreds or thousands... although if you wanted to browse through that many, Fastone Image Browser (free) is well worth a look.

I used to use VLC, but for various reasons (which I forget) found Media Player Classic (https://mpc-hc.org/) better. I got that as part of Klite codecs; which I installed using Ninite (https://ninite.com/). If you haven't tried Ninite for suggesting and installing software give it a whirl. It's always the first thing I go to with a new PC.
I used to use that, but on older machines VLC has many options which will keep those machines making themselves useful, if you e experience skippy playback.
 

guerney

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When our group was working on image processing
That's very interesting! Noted in case I have an image processing question (at some point) and may send you a PM, which you of course will be free to ignore, if such a PM ever arrives.
 

sjpt

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I'd rather just deal with one or two frames I capture during playback ... instead of having to deal with
I was thinking of maybe half a dozen to a dozen frames, to help reduce the noise and motion blur.

I might revisit VLC and Fastone some time, things may well have changed since I last used either of them.
 

guerney

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I was thinking of maybe half a dozen to a dozen frames, to help reduce the noise and motion blur.
I don't care too much about noise - the noise/graniness at ISO 1600 isn't gigantic and globular alphanumeral view impeding like ISO 6400 is... that's utterly unusable for dark scenes. At ISO 1600, it's going to be noisy on such a small sensor at such fast shutter speed regardless, and VLC is decoding HVEC, which at GoPro's high bitrate isn't going to be responsible for the noise - I doubt if things will be any clearer.
 
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