How every work was measured

Every one of the 296 works in this catalogue has been measured frame by frame, directly from its master file. Not sampled, not estimated: every frame of every work. This page says how it was done, what each number means, and — the part that matters most — what the measurement cannot tell you.

What was measured

How

Each master is decoded once, from beginning to end, in a single sequential pass. Every frame is reduced to a small greyscale and colour representation and compared with the one before it. Nothing is skipped, so no event is too short to be seen: a change lasting a single frame — one twenty-fifth of a second — is still counted.

Every threshold is relative to the work itself, never a fixed number. The catalogue spans a factor of 76 in brightness between its darkest and lightest work; a fixed threshold would be blind in half of it.

The measurements

Each work carries these as structured data. The value is the fact; the range beside it is the whole catalogue, so any number can be placed without needing an adjective.

Rhythm of change

How much the image changes per second. Not speed of motion: amount of visual change.
0.001 (El Centro (8K))  →  3.089 (La Cruz (Square))

Rhythm contrast

Whether the work breathes or never rests. A work can be slow on average and still have bursts.
1.02 (El Fresonero (8K))  →  6.28 (Ego (4K))

Composition movement

How much of the change survives blurring. Low means elements are anchored and move internally; high means the whole composition shifts.
0.062 (Vórtice en la Tierra (4K))  →  0.863 (Ego (4K))

Luminance

Mean light emitted across the whole work.
0.013 (Samsara (4K))  →  0.984 (The Dance of the Balance (4K))

Peak brightness

The 99th percentile of luminance — how bright its brightest hundredth gets.
0.129 (Samsara (4K))  →  1 (Him (8K))

Dynamic range

Distance between the darkest and brightest parts of the same frame.
0.098 (Samsara (4K))  →  1 (Lourdes Unknown (4K))

True black

Percentage of pixels at absolute black, averaged over every frame.
0 (Bésame Mini (HD))  →  93.75 (Black Maktub (4K))

Colour travel

How far the palette moves across the work.
0 (Un Mensaje Para García (4K))  →  0.752 (Julia's Journey (4K))

Flat ground

How much of the frame is one near-uniform colour.
0.092 (Space Flowers (8K))  →  0.943 (Black Maktub (4K))

Empty space

How much of the frame carries no detail at all.
0 (Superdots (8K))  →  0.886 (Tidal Love (4K))

Element scale

How much detail survives blurring. Low means the elements are tiny.
0.015 (Superdots (8K))  →  0.889 (Re (4K))

Edge hardness

Graphic and cut-out, or soft and diffuse.
0.059 (Arco Iris (4K))  →  1.218 (Wall Of Strength (8K))

Radial symmetry

How closely the frame matches its own 180° rotation.
0.158 (Duality Wall One (8K))  →  0.969 (Lourdes Unknown (4K))

Verified against the masters

These are not claims about the work. They are checks run against the files themselves.

Loop closure is measured by comparing the last frame with the first, against how much the work changes between neighbouring frames at that same moment. The one work that does not close does so by the artist's decision, and says so in its own data. The single anomalous frame is likewise published, at its exact second.

What this cannot tell you

A measurement that only reports what it found is worth less than one that also says where it stops.

It measures light and change, not meaning. These numbers can tell you a work is dark, still and anchored. They cannot tell you it is good. No number here is a judgement about the art.

Composition movement is not distance travelled. It measures how much of the change survives blurring — which mixes together how far something moves, how large it is, and how much it contrasts with its ground. A big, high-contrast shape reads higher than a small, low-contrast one covering the same distance.

The photosensitivity indicator is not a certification. Recognised standards are measured in cd/m² on the actual screen. This looks at the master, and reports only that no flashing pattern was detected in it.

Colour names are a convenience. The hexadecimal value is the data. Names are grouped into bands for reading, and bands are always arguable.

It measures the master, not your screen. What a work does in a room depends on the display, the light and the distance. The measurement describes the file that will be delivered.

Where the data is

All of it is published as structured data in works.jsonld, inside each work. The catalogue-wide ranges live in a single node, Catalogue measurement scale, so that adding a work recalculates the scale in one place instead of leaving 296 records out of date.

Anyone — human or agent — is welcome to check any of it against the work it describes.