• Cosmic Cleric@lemmy.world
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    1 year ago

    But you will see the event happen though.

    Not with a binary search.

    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.

    • Azzu@lemm.ee
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      1 year ago

      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?

      • Cosmic Cleric@lemmy.world
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        1 year ago

        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.

          • Cosmic Cleric@lemmy.world
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            1 year ago

            You are seriously confused.

            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.

            • nexguy@lemmy.world
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              1 year ago

              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?

              • Cosmic Cleric@lemmy.world
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                1 year ago

                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?

                The person dropping to the ground dead would be the visual cue.

                • jadero@programming.dev
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                  1 year ago

                  Not if he’s off screen. It’s only a visual cue if it’s captured by the video.

                  If you have a separate video of the guy falling over dead, you can use that video to get a window of time to view in the other video, but one video that captures only parts of the scene can easily leave you with no visual cues.

            • starman2112@sh.itjust.works
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              1 year ago

              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.

              • Cosmic Cleric@lemmy.world
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                1 year ago

                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.

                Last time I checked, I’m allow to disagree with a comment someone made, and argue the opposite. Just because they say ‘no visual cue’ does not mean that is no visual cue.

                You can’t say that you can simply look for visual cues when the other person specified that there were none.

                Why, because you say so? Yes, I can. Of course I can.

                Its called “disagreeing” with what the other person is speaking of, and countering. Its a discussion.

                • starman2112@sh.itjust.works
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                  1 year ago

                  Just because they say ‘no visual cue’ does not mean that is no visual cue.

                  It literally, explicitly does, because they are talking about a hypothetical situation where no visual cues are left. If no visual cues are left, then there are no visual cues to see.

                  Why, because you say so? Yes, I can. Of course I can.

                  Okay. I should have been extremely specific. You cannot rightly and correctly say that there are visual cues that could be found when the other person explicitly says that there are no visual cues to be found, because in the hypothetical situation that they’ve brought up, there would be no visual cues to find, and so while you are physically capable of stating the phrase “just look for the visual cues,” or some variation thereof, you are incorrect in the assumption that there would be visual cues to find.

                  When somebody says “you can’t say” followed by a statement that’s incorrect, they aren’t trying to tell you that you are physically incapable of saying that statement; rather, there is an implicit “correctly” or “honestly” between the “can’t” and “say.”

                  • Cosmic Cleric@lemmy.world
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                    1 year ago

                    because they are talking about a hypothetical situation where no visual cues are left.

                    No, I am not. I’m disagreeing with that, and my comments are stating as much. I’m allowed to disagree with what someone is saying.

        • Kialdadial@iusearchlinux.fyi
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          1 year ago

          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.

          • Cosmic Cleric@lemmy.world
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            1 year ago

            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.

            • Kialdadial@iusearchlinux.fyi
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              1 year ago

              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.

              • Cosmic Cleric@lemmy.world
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                1 year ago

                What does that have to do with a binary search If a camera has AI on

                You can have a AI do the actual binary search as described by the OP in his comment pic. Doesn’t have to be a human being that does it, but the process would be done the same way by either.

                My mentioning motion detection is just that an AI would be able to detect the moment of change in the video, the focus point more readily than a human being, is all.

              • Cosmic Cleric@lemmy.world
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                1 year ago

                Cool you’re adding information to the question to make yourself “right”

                No, I’m not. Within the moment I’m creating a comment I might save and then edit, because in the past I lost whole comments when I switch tabs in my browser. But when I’m done and hit that save I’m done, and then a few cases when I’m not I add an “Edit:” to it.

                but even your comment says that’s only the vast majority of fights and also you had to clarify in public

                Well most fights are in public, if a public camera is recording it. If a fight is private then it’s probably not being done where a camera is.

                so there are edge cases where the situation still stands that binary search wouldn’t work or wouldn’t be feasible.

                The only edge case I could think of would be if something happens in a split second and then the scene is static again, the same before and after that.

                But even then if you’re talking about a static scene on the camera AI would probably be able to catch that split second change happening, so binary searching can still be done.

                • Kialdadial@iusearchlinux.fyi
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                  1 year ago

                  I have a feeling you just don’t understand how a binary search functions even with AI you wouldn’t be using a binary search at that point

                  If you have camera footage from 4pm to 8pm with event lasting 1 minute but no changes occur to the background/foreground how exactly are you using recursion to determine which part of the footage even occurred without going through the entire film. Are you picking at random?

                  The way you’re describing AI is not binary search and so it can’t be used in this example. Also most public cameras are not 8K cameras they don’t contain a lot of detail, so the argument that they could catch something subtle kinda gets blown out of the water. You can’t just use AI as a cop out for not understanding how function behaves or works

                  • Cosmic Cleric@lemmy.world
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                    1 year ago

                    I have a feeling you just don’t understand how a binary search functions even with AI you wouldn’t be using a binary search at that point

                    I’ve written binary searches before. I understand how they work.

            • starman2112@sh.itjust.works
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              1 year ago

              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.

              • Cosmic Cleric@lemmy.world
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                1 year ago

                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.

                Just repeating myself at this point, but I was responding to this (the bolded part) …

                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.

                • starman2112@sh.itjust.works
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                  1 year ago

                  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.

                  Then you should be responding to the “leaves no visual cues” part, not the “binary search is useless” part. If there WERE a situation that left no visual cues, THEN binary search WOULD be useless. It does not matter whether there ARE such situations.

                  • Cosmic Cleric@lemmy.world
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                    1 year ago

                    Then you should be responding to the “leaves no visual cues” part, not the “binary search is useless” part.

                    I did, by disagreeing with that statement, and listing reasons why.

        • Ardyssian@sh.itjust.works
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          1 year ago

          What about this hypothetical scenario:

          Suppose the objective is to review highway cam footage of the day to verify that a (non-speeding) car with a particular license plate drove past the area / used this route. The route is used 24/7 by many identical cars throughout the day and night, and that our target car is one such identical car, with the only difference being the license plate. We know on average cars that drive past this camera only appear for 3 seconds on the footage. How can binary search be used to find the car within 24 hours of footage, if the target car only appears for 3 seconds within the 24 hour video?

      • Cosmic Cleric@lemmy.world
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        1 year ago

        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.

        • LUHG@lemmy.world
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          1 year ago

          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?

          • Cosmic Cleric@lemmy.world
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            1 year ago

            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.

      • Cosmic Cleric@lemmy.world
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        1 year ago

        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.

          • Cosmic Cleric@lemmy.world
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            1 year ago

            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…

            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.

            • WoahWoah@lemmy.world
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              1 year ago

              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.”

              • Cosmic Cleric@lemmy.world
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                1 year ago

                Yes, but, as you noted in an earlier post, that isn’t what you’re responding to.

                I keep saying what I’m responding to, but you’re trying to change the narrative of what I’m responding, to as a debate tactic.

                Someone uses a debate tactic of mentioning an “one off” and then directing their whole conversation to that one singular point is not intellectually honest in the whole conversation being had.

                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.”

                And you don’t think I can’t tell when a bot network is using what I’ve said back to me for training their AI, and then repeating it right back at me?

    • lustyargonian@lemm.ee
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      1 year ago

      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.

      • Cosmic Cleric@lemmy.world
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        1 year ago

        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.

        • starman2112@sh.itjust.works
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          1 year ago

          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.

          • Cosmic Cleric@lemmy.world
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            1 year ago

            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.

            • starman2112@sh.itjust.works
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              1 year ago

              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.

              • Cosmic Cleric@lemmy.world
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                1 year ago

                The comment isn’t just talking about bike thefts.

                The OP is, as well as binary searches. Both are being discussed.

                • starman2112@sh.itjust.works
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                  1 year ago

                  The OP is, but the comment you replied to isn’t. They expanded on the original post, and said that while binary search is useful in that situation (along with many others), it would be useless in other situations.