If you were born between the 80s and the 90s, you’d probably remember the time before DVDs and good old VHS.
Given the standard of VHS video quality back then, pretty much of every video from the past was blurry; from movies, security camera footage and even conspiracy theory ‘evidence’. With the production of VHS ceasing last year, let’s go back to the future.
Back in 2017, around Valentine’s Day, a North Korean named Kim Jong-nam, believed to be the half-brother of North Korean dictator Kim Jong-un, was assassinated at KLIA2.
Less than a week later, Japanese broadcaster Fuji TV released a grainy CCTV footage showing a woman covering the victim’s face with something from behind before she hurriedly left the scene. Within a short timeframe, the perpetrator was identified and then detained with much praise to the local authorities.
So why are we still seeing blurry CCTV footage if they’re so much better than smartphone cameras, you ask?
This is because of image/video cropping on low resolution video.
Yes, that cropping. Just like what you do on Instagram.
So, when you crop a certain footage from a low resolution video, what you will get is a very noisy picture like this:
Also, there are other factors that affect a CCTV footage, such as compression when the recording is fed into a DVR set to be stored.
So, in case you TL;DR, CCTV footages are not bad quality in nature, it only happens when you want to crop a certain area out of the footage.
Oh, and in case you're wondering: noise is a type of visual distortion produced either by low light, pixel density, exposure and sensor size. Blur, on the other hand, happens when the sample video is recorded in low FPS and still image is captured from a frozen image frame.