How to Compress Images with Waves

June 28, 2018 Lucy Zhang & Sid Shanker

What is lossy compression?

Insight from Digital Signal Processing

We know we can decompose a complex wave into simple ones

But, are images waves?

A single row of pixels (white is 255, black is 0):

We can see that some components matter more than others here:

How do we break this signal into components?

Discrete Cosine Transform!

Key Idea: Transform "pixel values" into cosine coefficients

Once you have this representation, the data is ordered by importance

Performing the compression:

Full Pipeline:

Encode

Compress

Decode