Title basically says it all. I understand how photos and videos can trade quality for file size, but files like games or large folders can be shrunk into a .rar or .zip file, transferred, and pulled back out with no loss to functionality. How does that work? If nothing’s being taken away how is space being saved?
In: Technology
There are many different ways and tricks!
All of them a very technical but I’ll give you my favorite (and super basic) concept that blew my mind.
You know you could send an entire image from position A to position B right? But that’s a lot of pixels, which are a lot of data to send!
So one trick you can do is “predict” specific pixels based on previous information. How exactly you do that doesn’t matter right now, but it’s a bit of math that looks at your last image and says “well the next image must kinda look like this…”.
How does it help you compress the image? Well you can place one of those predictors not only at position B but ALSO position A.
So now you predict the same image on both “ends”, how does it decrease the amount of information traveling?
Simple, on position A you predict the next image, let’s call it I_predict. You also KNOW what the next image really looks like I_real.
You know that at position B you will predict the exact same image I_predict.
So what you can do now is simply send the information that corrects I_predict in a way that it results in I_real (which you acquire from comparing them at Position A) and say:
“Listen, I know you will think I_predict is the next image, and it almost is! Just correct these few pixels and you will be on spot!”.
Thereby drastically reducing the amount of data transferred, since you didn’t have to send an entire image, but only instructions to correct it.
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