Resizing Images - Computerphile

Nearest Neighbour and BiLinear resize explained by Dr Mike Pound

This video was filmed and edited by Sean Riley.

[tiltedtesseract]

"So there's a 3x3 image. It's- y'know, 's- high quality."

[TehBurek]

Bilinear sampling/scaling is used for almost everything[1] in modern real-time 3D graphics (3D games, etc.) because there are dedicated hardware parts for that operation in every GPU, and as such it's dirt cheap to use. Some games in some situations use nearest neighbour, usually for style, like Minecraft (blocky textures stay blocky however close you are).

Back in the early-to-mid '90s it was usually nearest neighbour everywhere, because there was no GPU to help out, and CPU couldn't afford to waste cycles on interpolation math for every single screen pixel (one read, one write VS one read, three pairs of subtraction, addition and multiplication, and then write). Early 3D home consoles, like Playstation 1. did the same.

The first Unreal game had an interesting approach (in its software rendering mode) - to use dithering instead of interpolation. In that way, no intermediate (interpolated) colours needed to be calculated, but the exact same source colours (like for nearest neighbour) were "shuffled" around to create an ilusion of gradient.

So yeah, those were my 5 cents, maybe someone will find it interesting.

(1 - trilinear and anisotropic just build on top of the same basic idea)

[JohnMichaelson]

Explaining bilinear and bicubic with the side view was very illustrative and conceptually helpful, thank you!

[RobustEnigma]

Damn I get so excited when Dr. Mike Pound is in the thumbnail. XD

[hugomelchers]

"If you're a pixel-artist, doing... uh, you know... pixel-art..."

[SleeveBlade]

I just love this guy :). Brilliant at explaining these things. He makes a lot of stuff sound real easy, and in this case it really is, but on myself or by the usual professor it would definitely take longer to understand. Or maybe I just have a different kind of attention in class than while watching YouTube. And the graphics always are on point as well. Not too much info to distract, but right enough to consume the information easier.

[Capeau]

Its 'simple' things like these we take for granted but when looked at closer it makes you realize how absurdly fast an average computer is these days. Being able to do this at a massive scale many times per second.

[stevesynan]

Why couldn't I have had teachers with such clarity when I was going through school? On some of these videos I gain more perspective in 10 minutes than I did with entire lectures in class. Keep up the great work, this channel is awesome!

[Jan-fe]

Really like this guy, he explains it so well and it's a joy to watch him talk about this stuff!

[JeoshuaCollins]

I think of this kind of stuff every time I see a cop-drama where they have some low resolution image and then magically "blow it up" to get a license plate number or something else that was clearly not visible before. That's not how this works, television!

[hesgrant]

Mike is just phenomenal at explaining how things work. What a brilliant guy.

[schogaia]

Mike is my favorite Computerphile member, I just love his videos

[MrTxiz]

more with Mike please! As a student of computer science I can tell that he is way more interesting to listen to than many of my professors!

[daledude]

Gee wonder why this has shown up in my feed today 😂

[drak]

More Mike videos, please. This guy has so good explanations and the way of talking, just wow. Good.

[marcinsobianowski]

"3x3 image. It's you know, high quality" lmfao xD

[typedef_]

Since you mentioned zooming out, can you do a video on anti-aliasing ?

[emanwe]

"But that's for another video"
Gah! Again you tease us with a cliffhanger!

[malteeaser]

I love this channel. I know about computers, and it confirms things I thought or gives me the small and fun details that you may not learn in uni.

[jony]

The animation at 7:49 was a brilliant clarification of what he was trying to get at.