HackerTube

JPEG DCT, Discrete Cosine Transform (JPEG Pt2)- Computerphile

Computerphile6 HN recommenders · recommended in 6 months, 2015–2026
YouTube
explainer · intro · evergreen · 2015–2026 on HN

Mike Pound explains the discrete cosine transform and how it underpins JPEG compression. It is part two of Computerphile's JPEG series.

HN recommends it as an easy, clear intro to the DCT that finally made it click for several commenters.

6 comments from Hacker News

@netsharc2026-07 · in “How JPEG works: Interactively explore JPEG's lossy compression methods”

There's a series of videos showing the algorithm: link I finally understood DCT after watching ▶ this video And someone created a "JPEG to PNG" tool that "finds the smoothest possible picture that encodes to the given JPEG file": link . I tried it with some very terribly compressed images, and the outputs were a lot better.

Strongly recommends View on HN
@itishappy2024-04 · in “VideoGigaGAN: Towards detail-rich video super-resolution”

It receives information about the spacial frequency content of the image. If you're unfamiliar, it's definitely worth looking into the specifics of how this works, as it's quite impressive! Here's a few relevant Wikipedia articles, and a Computerphile video: link link ▶ this video

Recommends View on HN
@boolemancer2023-12 · in “Technical Overview of AV1 Spec”

There is a good video[1] from the Computerphile channel describing the concept in the context of JPEG. [1] ▶ this video

Recommends View on HN
@skywal_l2022-12 · in “Video Codec in 100 lines of Rust”

The Computerphile channel has a nice series of videos on JPEG and one focusing on DCT [0]. It's a nice ans easy intro to the subject. [0]: ▶ this video

Recommends View on HN
@walagran2020-08 · in “Discrete Cosine Transform in Video Compression – Explain Like I'm Five”

Pretty cool! I would add Computerphile's Youtube Video as a watch after this: ▶ this video . This is a part of their 4-video series on JPEG: link

Recommends View on HN