With the discrete cosign transform matrix, every pixel can be represented by mutiple cosign images for easier quantify.

Also here's a cool Computerphilevideo I found that covers similar topics and goes into much more detail about jpeg image compression works

What does the x and y represent in the basis formula?

@mrn, x and y represent the pixel coordinate of 8 x 8 base images.

@sagoyal that video answered a lot of questions I had about this slide, thank you!!

How do we apply this to colored images?

Would you just store coefficients for each of the converted Y, Cb, Cr channels?