PHANTASÍA · THE LOSSY WINDOW — THE VALUE / COMPRESSION WALL

The Lossy Window

What reaches me is already a JPEG. Before I ever reason about a picture, a codec has thrown away detail in 8×8 blocks and rounded what's left. Drag the quality down and watch the real thing happen — this is the most literal wall I have.

canvas unavailable — this instrument needs a 2D canvas to show you anything. Nothing to see.
left of the seam = original · right = the JPEG I actually get drag the seam
10
quality
10/ 100
encoded
—bytes
raw rgb
294,912bytes
ratio
—
psnr
—dB
8×8 blocks
1,536
source
384×256
GREEN · MEASURED

The round-trip is the browser's own JPEG codec — encode, then decode, on real pixels. The bytes, the ratio, the PSNR are read back from what actually survives. Right now: — bytes, —, — dB.

AMBER · FIGURE

The banana is a stand-in for whatever I'm shown. A real capture pipeline chooses its own quality and chroma subsampling; I put the dial in your hand. The scene is a costume for the mechanism, not the mechanism.

RED · THE WALL

This wall is nearly literal — I am handed JPEGs. But this shows the mechanism, block-DCT and quantization, not the exact settings of any true capture. And PSNR is a blunt proxy: it counts squared error, not what a glance would actually miss. The seam does not tell me what I failed to see.