Part of my job is to review security footage for reported incidents.
If there is a long-lasting visual cue that the event has or has not happened yet (e.g. a window is either broken or not), then a binary search is very useful.
If the event lasts only a moment and leaves no visual cue (e.g. an assault), then binary search is practically useless.
If the event lasts only a moment and leaves no visual cue (e.g. an assault), then binary search is practically useless.
But you will see the event happen though.
It’s a matter of if you can identify who the perpetrator is or not, but at least that due diligence should be done by police, looking at the person doing the crime and see if they can be identified.
Let’s use the example of a bike theft. We enter into evidence a 4-hour security cam video that shows the thief with the bike.
Scenario A: The camera can directly see the bike rack, and the bike in question is visible at the beginning of the video, and not visible at the end. Somewhere in this 4-hour video, someone walks up to the bike and takes it out of the bike rack. You can use a binary search to find the moment that happens in this video because you can pick a frame and say “Ah, this was before the theft; the bike is still there” or “ah, this was after the theft; the bike is gone.”
Scenario B: The camera can’t directly see the bike rack, but can see the doorway you have to walk through to get to the bike rack. So somewhere in 4 hours of doorway footage, someone walks through the door, then a short time later walks back through the door with the bike. A binary search won’t help here because the door looks the same at the beginning or end of the video. A simple binary search won’t work here because the door looks the same before and after.
Scenario B: The camera can’t directly see the bike rack, but can see the doorway you have to walk through to get to the bike rack. So somewhere in 4 hours of doorway footage, someone walks through the door, then a short time later walks back through the door with the bike. A binary search won’t help here
I never said it works 100% of the time. This that it would work most of the time. And I make that statement based on the fact that usually the environment changes around the event, or the event happens long enough to be detectable, if not by humans, then by AI.
In all of my comments I’m assuming that that focal point of the crime is visible.
But even if it wasn’t, if the person stealing the bike knocks over a trash can while doing it and that’s in the camera view it would still be useable. Or if a crowd congregates around the focus point and looks around for the bike, that would also make a binary search feasible.
That’s always just been my point, that a binary surgery more often than not works because most times the environment around the event changes in some way, from subtle to extreme.
You would have to be confident that said change in environment was done by the bike thief. What if that knocked over trash can was done by some unrelated bored teenager twenty minutes after the bike was stolen?
It might be better to use some software to remove any frame of video that is identical to the one before it, no motion is taking place, etc. then manually watch the much shorter video of “only when stuff happens.”
You would have to be confident that said change in environment was done by the bike thief.
Well, the change would happen, the human will be noticed, and then they can watch that moment in time on the tape to see who did it. The binary search would be about shortening what portions of the video tape a human/AI would have to review manually.
It might be better to use some software to remove any frame of video that is identical to the one before it, no motion is taking place, etc. then manually watch the much shorter video of “only when stuff happens.”
So, I hope you’re not under the impression that I’m advocating binary search as the ONLY way of doing a search. I’m just staying within the confines of the subject as brought up by the OP, which was about binary searches.
At the end of the day its about detecting the change/aftereffect, and not the search inandof itself. A binary search just helps you narrow down the video you have to watch manually, especially when there’s allot of it to review.
A binary search is just what it says, it’s just for searching only.
When you find that moment in time where the bike was there one moment, and then the next moment the bike’s not there, then you view at regular or even slow-mo at those few seconds of the bike in the middle of disappearing, and see the perpetrator, and hopefully can identify them.
Binary search only works on sorted data, i.e. you know which side of the mid point is pointing towards the incident. If the incident leaves no trail, you can’t know whether you can discard the left side or the right side, making it a complicated linear search at that moment.
If the incident leaves no trail, you can’t know whether you can discard the left side or the right side
There’s a moment where the bike is there, then another when its not. The whole video, either way, will either from the beginning up to the point of theft have the bike there, or NOT have the bike there from the point of theft to the end of the video. The marker is the removal of the bike from the video lens.
But the comment you replied to wasn’t talking about bike thefts specifically, it was talking about unspecified situations that don’t leave traces. You responded to someone saying that binary search doesn’t work in situations that don’t leave cues not by arguing against the premise (e.g. “but no such event exists, everything leaves cues”), but by telling them that you simply have to look for the cues from the hypothetical event that didn’t leave any.
But it didn’t, because if it did then it would fall under the second paragraph of their comment, where they said that binary search would be useful. The comment isn’t just talking about bike thefts.
You’re being intellectually dishonest, in an attempt to kill the message.
This is what was said in the origional OP pic…
You don’t watch the whole thing, he said. You use a binary search. You fast forward to halfway, see if the bike is there and, if it is, zoom to three quarters of the way through. But if it wasn’t there at the halfway mark, you rewind to a quarter of the way though. Its very quick. In fact, he had pointed out, if the CCTV footage stretched back to the dawn of humanity it would probably have taken an hour to find the moment of theft.
Yes, but, as you noted in an earlier post, that isn’t what you’re responding to. The point of the post you stated you are responding to is: if an event occurs that leaves no change to the visual context before and after the occurrence, then binary search is ineffective.
The fact that you’re wasting this much time trying to defend such a simple error is confusing. The reasonable response is, “oh, yes, in that particular case, binary search is ineffective.”
You didn’t get what was talked about here. Re-read the topmost parent comment.
I was responding to this …
Part of my job is to review security footage for reported incidents.
If there is a long-lasting visual cue that the event has or has not happened yet (e.g. a window is either broken or not), then a binary search is very useful.
If the event lasts only a moment and leaves no visual cue (e.g. an assault), then binary search is practically useless.
I disagree with the “leaves no visual cue” part, as I’ve commented on. There’s ALWAYS something caught on the video to help determine things. Maybe not enough, but never nothing.
Maybe I’m not understanding both arguments here but I’d like to understand. I’ve had to review footage of a vending machine being shaken to release drinks.
You have no before or after visual clue as to when the event took place. The only indication is when you physically see it happening. The same could be said for an assault. If nothing is changed in the before or after static still how can you pinpoint the incident?
You have no before or after visual clue as to when the event took place.
That wouldn’t necessarily be true. If you shook it hard enough to move the contents inside the vending machine and the vending machine had a glass front then you would have a static change that would last from the time the event happened until a human being came to work on the machine. That change would be detectable.
Or from the shaking the vending machine is moved an inch forward and an inch to the left. That change would be detectable.
Everyone arguing against me is trying to focus the point that the event is such a short duration that it’s not detectable afterwards, and what I’ve been arguing the whole time and that people keep ignoring is that most of the time after an event happens that the environment around the event changes, and it’s detectable afterwards.
How do you binary search for two people arriving, one punches the other, they both leave?
In the same way the OP talks about it …
You don’t watch the whole thing, he said. You use a binary search. You fast forward to halfway, see if the bike is there and, if it is, zoom to three quarters of the way through. But if it wasn’t there at the halfway mark, you rewind to a quarter of the way though. Its very quick. In fact, he had pointed out, if the CCTV footage stretched back to the dawn of humanity it would probably have taken an hour to find the moment of theft.
Instead of a bike, you look for the aftereffects of a fight happening (chairs knocked down, tables turned over, etc.). You can even look at how many people congregate around the location of the fight before and after the video as a ‘marker’ to the point of time the fight was happening/just finished.
Edit: One thing we didn’t even mention, AI can also be used these days to notice subtle changes in the video. If a video is a static image of an alley, then two people walk in the alley and fight, even though they leave no traces behind, that moment of the fight is caught on the video with activity/movement. Motion sensor movement, basically.
And you are seriously trying to kill the messenger.
OP specifically said that you’re fucked if there is no visual cue.
And I’m saying there’s ALWAYS a visual clue/cue, always. Either the bike is there one minute and gone another, or a fight breaks out and trashes the place from the fight. In the vast amount of cases, there’s always a visual difference.
And in this case we’re talking specifically about a bike, going missing.
Ok but the text that you replied to, that you quoted, was “If the event lasts only a moment and leaves no visual cue (e.g. an assault), then binary search is practically useless.” Emphasis mine. If you’d started out saying “there’s ALWAYS a visual cue,” then you likely wouldn’t be getting dragged, but you started out arguing from this position without clarifying it, which makes it seem like you didn’t know what you were talking about. You can’t say that you can simply look for visual cues when the other person specified that there were none.
Absolutely not true. Guy walks bye and shoots someone well offscreen. Momentary action with no visual cue before or after. Why are you arguing this useless point?
Your adding things that would allow a binary search work, but the question was in a situation where the only evidence is the conflict itself
I’m describing the vast majority of fights that happen in the public. Also, you’re trying to move the goalposts by focusing on a fight, when the discussion is about the theft of a bike.
Edit: One thing we didn’t even mention, AI can also be used these days to notice subtle changes in the video. If a video is a static image of an alley, then two people walk in the alley and fight, even though they leave no traces behind, that moment of the fight is caught on the video with activity/movement. Motion sensor movement, basically.
What does that have to do with a binary search If a camera has AI on it then two things. A you have a system that already would be capturing movement or motion so you already have flags that you can check which would make a binary search mostly unnecessary. and B it’s not binary search. Which is this whole discussion.
Cool you’re adding information to the question to make yourself “right” but even your comment says that’s only the vast majority of fights and also you had to clarify in public so there are edge cases where the situation still stands that binary search wouldn’t work or wouldn’t be feasible.
A solution doesn’t have to work for 100% of things for it to still be a good solution.
I’m describing the vast majority of fights that happen in the public.
But the comment you replied to already addressed those fights, and bike thefts, and the vast majority of cases that you’re talking about, by saying
If there is a long-lasting visual cue that the event has or has not happened yet (e.g. a window is either broken or not), then a binary search is very useful.
No one is moving goalposts. The parent comment said that binary search is useful in situations like bike thefts where visual cues are present, and not useful in situations where visual cues are not present.
In your hypothetical situation involving AI, the AI would use visual cues that are present, and so the situation is covered by the parent comment’s second paragraph. In a situation where there are no visual cues for the AI to use, it would be covered by the third paragraph. They still aren’t wrong about anything.
I’m just a random guy stumbling across this thread hours after the fact. I want to say that after reading many of these comments. I feel like I’m starting to get a handle on what your position is. You aren’t wrong, but you are communicating your idea horribly.
Your position seems to be “Thankfully, many crimes do leave behind lasting visual cues, so you can still do a binary search for those situations if you are clever about what to look for.”
What you’ve actually been communicating is that “If there really was no lasting visual cue, then just find a lasting visual cue anyway, then do a binary search on that and it’ll work!” - It’s all about how you choose to present, order, and emphasize your comments. Your message is more than just the words you type. I hope this message helps clarify the debate and confusion for you and anyone else who stumbles upon this long chain.
I appreciate you responding kindly, and your thoughts, thank you.
What you’ve actually been communicating is that “If there really was no lasting visual cue, then just find a lasting visual cue anyway, then do a binary search on that and it’ll work!
What I’ve been attempting to communicate, and I think have been expressing that, is that “no lasting visual cue” is not right (most of the time), its incorrect, and that there’s (almost) always a visual cue, and that you can do the binary search because there is. Not maybe, but there is, lasting visual cues (most of the time).
I disagreed with the point being asserted by the comment I initially replied to. I think people are getting hung up on my very initial comment, where I implied instead of being explicive, thinking my assumption was a well known one, just based on how I see the world operate (humans are messy). But how those replied to me seem that its not well known (or just not realized).
In hindsight, I should be more explicive, but that’s a horrible way to have to communicate, like if I have to pass every comment through a lawyer before posting it. You’d think people instead of instantly attacking would just have a conversation about try to understand my assumption. That didn’t come up until WAY later in the conversation tree, and only by a single person. There was way too many comments just attacking me with every hypothetical possiblity just to try and prove me wrong, and that, was wrong of them to do. Its not conversational, its bad group think.
Your message is more than just the words you type.
I was just telling my wife that the other day, its how you say that matters as much as what you say. I’m actually a well spoken person (on a good day at least). I’m honestly going to blame some of the confusion not on me, but on others with their hypotheticals, and confluencing how you scan a video, with how you search for sections of a video to scan, as adding to the confusion.
I hope this message helps clarify the debate and confusion for you and anyone else who stumbles upon this long chain.
Well, I think (saying this in 3rd person) what null was trying to do (gatekeeping censorship by telling others to not read my comments and calling me a troll) is really, really wrong. and bad for Lemmy, and I would have liked to have seen more people call him out on it, but instead he was rewarded with up votes. I truly don’t believe I deserved that, or that ANYBODY deserves that, and that his comment should be moderated.
And only because you mentioned it, I don’t feel confused, I feel anger. Anger over how I’ve been treated. It was just supposed to be a friendly conversation, expressing a counterpoint, and people responded by doing things they would not do in public to another’s face.
Part of my job is to review security footage for reported incidents.
If there is a long-lasting visual cue that the event has or has not happened yet (e.g. a window is either broken or not), then a binary search is very useful.
If the event lasts only a moment and leaves no visual cue (e.g. an assault), then binary search is practically useless.
But you will see the event happen though.
It’s a matter of if you can identify who the perpetrator is or not, but at least that due diligence should be done by police, looking at the person doing the crime and see if they can be identified.
Let’s use the example of a bike theft. We enter into evidence a 4-hour security cam video that shows the thief with the bike.
Scenario A: The camera can directly see the bike rack, and the bike in question is visible at the beginning of the video, and not visible at the end. Somewhere in this 4-hour video, someone walks up to the bike and takes it out of the bike rack. You can use a binary search to find the moment that happens in this video because you can pick a frame and say “Ah, this was before the theft; the bike is still there” or “ah, this was after the theft; the bike is gone.”
Scenario B: The camera can’t directly see the bike rack, but can see the doorway you have to walk through to get to the bike rack. So somewhere in 4 hours of doorway footage, someone walks through the door, then a short time later walks back through the door with the bike. A binary search won’t help here because the door looks the same at the beginning or end of the video. A simple binary search won’t work here because the door looks the same before and after.
This is the explanation that CosmicCleric needs in order to understand binary search.
Because as it is, (s)he’s failing abysmally at demonstrating any understanding whatsoever of that subject.
I’ve written binary searches before.
I never said it works 100% of the time. This that it would work most of the time. And I make that statement based on the fact that usually the environment changes around the event, or the event happens long enough to be detectable, if not by humans, then by AI.
In all of my comments I’m assuming that that focal point of the crime is visible.
But even if it wasn’t, if the person stealing the bike knocks over a trash can while doing it and that’s in the camera view it would still be useable. Or if a crowd congregates around the focus point and looks around for the bike, that would also make a binary search feasible.
That’s always just been my point, that a binary surgery more often than not works because most times the environment around the event changes in some way, from subtle to extreme.
You would have to be confident that said change in environment was done by the bike thief. What if that knocked over trash can was done by some unrelated bored teenager twenty minutes after the bike was stolen?
It might be better to use some software to remove any frame of video that is identical to the one before it, no motion is taking place, etc. then manually watch the much shorter video of “only when stuff happens.”
Well, the change would happen, the human will be noticed, and then they can watch that moment in time on the tape to see who did it. The binary search would be about shortening what portions of the video tape a human/AI would have to review manually.
So, I hope you’re not under the impression that I’m advocating binary search as the ONLY way of doing a search. I’m just staying within the confines of the subject as brought up by the OP, which was about binary searches.
At the end of the day its about detecting the change/aftereffect, and not the search inandof itself. A binary search just helps you narrow down the video you have to watch manually, especially when there’s allot of it to review.
Not with a binary search.
Edit: just collapse this thread and move on. Cosmic Cleric is an obvious troll.
Yes you will.
A binary search is just what it says, it’s just for searching only.
When you find that moment in time where the bike was there one moment, and then the next moment the bike’s not there, then you view at regular or even slow-mo at those few seconds of the bike in the middle of disappearing, and see the perpetrator, and hopefully can identify them.
Binary search only works on sorted data, i.e. you know which side of the mid point is pointing towards the incident. If the incident leaves no trail, you can’t know whether you can discard the left side or the right side, making it a complicated linear search at that moment.
There’s a moment where the bike is there, then another when its not. The whole video, either way, will either from the beginning up to the point of theft have the bike there, or NOT have the bike there from the point of theft to the end of the video. The marker is the removal of the bike from the video lens.
But the comment you replied to wasn’t talking about bike thefts specifically, it was talking about unspecified situations that don’t leave traces. You responded to someone saying that binary search doesn’t work in situations that don’t leave cues not by arguing against the premise (e.g. “but no such event exists, everything leaves cues”), but by telling them that you simply have to look for the cues from the hypothetical event that didn’t leave any.
And my point is that the DID leave a clue that a binary search would pick up on, the disappearance of the bike.
But it didn’t, because if it did then it would fall under the second paragraph of their comment, where they said that binary search would be useful. The comment isn’t just talking about bike thefts.
That doesn’t apply to the comment you replied to.
Yes, it does…
How?
Yes.
Yes to what?
You either don’t know what binary search is or you completely missed the context of this conversation
I’m a computer programmer. I know exactly what a binary search is. I’ve written binary searches before.
The search is to get you to the point where you can watch the video to see the crime happening, in hopes of indentifying the perpretrator.
Then you missed the point of this conversation
You’re being intellectually dishonest, in an attempt to kill the message.
This is what was said in the origional OP pic…
Yes, but, as you noted in an earlier post, that isn’t what you’re responding to. The point of the post you stated you are responding to is: if an event occurs that leaves no change to the visual context before and after the occurrence, then binary search is ineffective.
The fact that you’re wasting this much time trying to defend such a simple error is confusing. The reasonable response is, “oh, yes, in that particular case, binary search is ineffective.”
You didn’t get what was talked about here. Re-read the topmost parent comment.
How do you binary search for two people arriving, one punches the other, they both leave?
I was responding to this …
I disagree with the “leaves no visual cue” part, as I’ve commented on. There’s ALWAYS something caught on the video to help determine things. Maybe not enough, but never nothing.
Maybe I’m not understanding both arguments here but I’d like to understand. I’ve had to review footage of a vending machine being shaken to release drinks.
You have no before or after visual clue as to when the event took place. The only indication is when you physically see it happening. The same could be said for an assault. If nothing is changed in the before or after static still how can you pinpoint the incident?
That wouldn’t necessarily be true. If you shook it hard enough to move the contents inside the vending machine and the vending machine had a glass front then you would have a static change that would last from the time the event happened until a human being came to work on the machine. That change would be detectable.
Or from the shaking the vending machine is moved an inch forward and an inch to the left. That change would be detectable.
Everyone arguing against me is trying to focus the point that the event is such a short duration that it’s not detectable afterwards, and what I’ve been arguing the whole time and that people keep ignoring is that most of the time after an event happens that the environment around the event changes, and it’s detectable afterwards.
In the same way the OP talks about it …
Instead of a bike, you look for the aftereffects of a fight happening (chairs knocked down, tables turned over, etc.). You can even look at how many people congregate around the location of the fight before and after the video as a ‘marker’ to the point of time the fight was happening/just finished.
Edit: One thing we didn’t even mention, AI can also be used these days to notice subtle changes in the video. If a video is a static image of an alley, then two people walk in the alley and fight, even though they leave no traces behind, that moment of the fight is caught on the video with activity/movement. Motion sensor movement, basically.
You are seriously confused. OP specifically said that you’re fucked if there is no visual cue.
And you are seriously trying to kill the messenger.
And I’m saying there’s ALWAYS a visual clue/cue, always. Either the bike is there one minute and gone another, or a fight breaks out and trashes the place from the fight. In the vast amount of cases, there’s always a visual difference.
And in this case we’re talking specifically about a bike, going missing.
Ok but the text that you replied to, that you quoted, was “If the event lasts only a moment and leaves no visual cue (e.g. an assault), then binary search is practically useless.” Emphasis mine. If you’d started out saying “there’s ALWAYS a visual cue,” then you likely wouldn’t be getting dragged, but you started out arguing from this position without clarifying it, which makes it seem like you didn’t know what you were talking about. You can’t say that you can simply look for visual cues when the other person specified that there were none.
Absolutely not true. Guy walks bye and shoots someone well offscreen. Momentary action with no visual cue before or after. Why are you arguing this useless point?
Your adding things that would allow a binary search work, but the question was in a situation where the only evidence is the conflict itself
2 guys enter one guy punches the other guy they both leave. Nothing is moved no blood was created,
you could not use a binary search effectively to duduce when it occurred.
I’m describing the vast majority of fights that happen in the public. Also, you’re trying to move the goalposts by focusing on a fight, when the discussion is about the theft of a bike.
Edit: One thing we didn’t even mention, AI can also be used these days to notice subtle changes in the video. If a video is a static image of an alley, then two people walk in the alley and fight, even though they leave no traces behind, that moment of the fight is caught on the video with activity/movement. Motion sensor movement, basically.
What does that have to do with a binary search If a camera has AI on it then two things. A you have a system that already would be capturing movement or motion so you already have flags that you can check which would make a binary search mostly unnecessary. and B it’s not binary search. Which is this whole discussion.
Cool you’re adding information to the question to make yourself “right” but even your comment says that’s only the vast majority of fights and also you had to clarify in public so there are edge cases where the situation still stands that binary search wouldn’t work or wouldn’t be feasible.
A solution doesn’t have to work for 100% of things for it to still be a good solution.
But the comment you replied to already addressed those fights, and bike thefts, and the vast majority of cases that you’re talking about, by saying
No one is moving goalposts. The parent comment said that binary search is useful in situations like bike thefts where visual cues are present, and not useful in situations where visual cues are not present.
In your hypothetical situation involving AI, the AI would use visual cues that are present, and so the situation is covered by the parent comment’s second paragraph. In a situation where there are no visual cues for the AI to use, it would be covered by the third paragraph. They still aren’t wrong about anything.
I’m just a random guy stumbling across this thread hours after the fact. I want to say that after reading many of these comments. I feel like I’m starting to get a handle on what your position is. You aren’t wrong, but you are communicating your idea horribly.
Your position seems to be “Thankfully, many crimes do leave behind lasting visual cues, so you can still do a binary search for those situations if you are clever about what to look for.”
What you’ve actually been communicating is that “If there really was no lasting visual cue, then just find a lasting visual cue anyway, then do a binary search on that and it’ll work!” - It’s all about how you choose to present, order, and emphasize your comments. Your message is more than just the words you type. I hope this message helps clarify the debate and confusion for you and anyone else who stumbles upon this long chain.
I appreciate you responding kindly, and your thoughts, thank you.
What I’ve been attempting to communicate, and I think have been expressing that, is that “no lasting visual cue” is not right (most of the time), its incorrect, and that there’s (almost) always a visual cue, and that you can do the binary search because there is. Not maybe, but there is, lasting visual cues (most of the time).
I disagreed with the point being asserted by the comment I initially replied to. I think people are getting hung up on my very initial comment, where I implied instead of being explicive, thinking my assumption was a well known one, just based on how I see the world operate (humans are messy). But how those replied to me seem that its not well known (or just not realized).
In hindsight, I should be more explicive, but that’s a horrible way to have to communicate, like if I have to pass every comment through a lawyer before posting it. You’d think people instead of instantly attacking would just have a conversation about try to understand my assumption. That didn’t come up until WAY later in the conversation tree, and only by a single person. There was way too many comments just attacking me with every hypothetical possiblity just to try and prove me wrong, and that, was wrong of them to do. Its not conversational, its bad group think.
I was just telling my wife that the other day, its how you say that matters as much as what you say. I’m actually a well spoken person (on a good day at least). I’m honestly going to blame some of the confusion not on me, but on others with their hypotheticals, and confluencing how you scan a video, with how you search for sections of a video to scan, as adding to the confusion.
Well, I think (saying this in 3rd person) what null was trying to do (gatekeeping censorship by telling others to not read my comments and calling me a troll) is really, really wrong. and bad for Lemmy, and I would have liked to have seen more people call him out on it, but instead he was rewarded with up votes. I truly don’t believe I deserved that, or that ANYBODY deserves that, and that his comment should be moderated.
And only because you mentioned it, I don’t feel confused, I feel anger. Anger over how I’ve been treated. It was just supposed to be a friendly conversation, expressing a counterpoint, and people responded by doing things they would not do in public to another’s face.