This document discusses the history and technical aspects of image compression technologies used for digital media. It traces the development from early lithography and photography in the 1800s through technologies like television, fax machines, and digital codecs. It examines key aspects of standards like H.261 used for video conferencing, including its hierarchical structure, use of color spaces like YCbCr, keyframes, and vector prediction. It raises issues around how these technologies encode images in ways that commodify and average information according to probabilistic and protocol-driven logics, reflecting the rise of database-centric economies.

1. >>> Problems of periodisation 2:
>>> screen geometries
A hundred and fifty years ago, two inventions revolutionised the image: lithography and photog-
raphy. Combined in contemporary photolitho presses , large-scale printing of photographs lead
us into a new set of mathematised techniques. Refined through fax, TV and digital transmission,
our imaging technologies are dominated by grids. Is the unacknowledged presence of tiny squares
just a random blip in a chaotic cosmos, or perhaps a structural characteristic of the society we
now inhabit: the database economy.
100-583 HISTROY AND PHILOSOPHY OF MEDIA 2010

2. Richard Parkes Bonington (1802-1828)
Tour du gros horloge, Évreux Lithograph, 331mm x 245mm
(detail of clockface above)

3. William Henry Fox Talbot, Latticed Window at
Lacock Abbey, 1835

4. Stephen H. Horgan, Steinway Hall, New York Daily Graphic,
December 2, 1873: first prited halftone photograph.

5. Bell Labs Wirephoto, first commercial transmission, New York 1935

6. The Quatermass Experiment, BBC TV, 1953, dir Rudolph Cartier, scr Nigel Kneale

7. Cathode Ray Tube
Trinitron Mask

8. LCD sub-pixel

15. H.261 Codec
STRUCTURE used to do the ‘in-betweening’, extrapolating from
‘a hierarchical structure with four primary layers. first and last frames the action needed to move
From top to bottom the layers are: Picture; Group of from one to the other. This information is encoded
Blocks, or slice, or video picture segment; Macrob- not as full-frame animation but as an instruction set,
lock; Block’ (ITU 2005:13 which requires far fewer lines of code. As the Flash
Video white paper notes, ‘A lower keyframe rate
COLOUR (such as one keyframe every six seconds) will result
YCbCr, which codes for luminance (Y) and two chro- in a softer or blurrier image but reduces the band-
ma channels (C), blue and red, on the principle that width demand’ (Macromedia 2004: 13).
the panchromatic Y channel captures the necessary
detail, while the absence of green (as used in almost VECTOR PREDICTION
all colour film, television and high-end storage media Vectors predict movement based on sequence from
like DVD and Blu-Ray) minimises redundancy be- an initial image. Encoding artefacts are increasingly
cause the green channel overlaps with both red and likely in hand-held sequences when the prediction
blue, especially in the yellow segment of the spec- system is more likely to predict wrongly or as the
trum. This is a variant of 8-bit colour graphics, which Flash Video white paper has it, ‘If your camera is not
allows a range of 256 colours steady, most of the image moves, causing a high per-
centage of pixels in the video to change from frame
KEYFRAMES to frame. A steady camera reduces the number of
uncompressed frames which are used as a reference pixels that change from frame to frame, giving you
for filling in compressed frames that come between better quality at higher compression rates (lower
them. In Flash vector animation, a similar process is data rates’ (Macromedia 2004: 11).

16. ISSUES
1. UNIT ENUMERATION = commodity equivalence, exchangability
2 AVERAGING = biopolitical management of probabilty
3. PREDICTIVE SCANNING = protocological control
=> DATABASE ECONOMY
Ivan Sutherland demonstrating Sketchpad, 1963

17. Methodological Principles
Consideration - of the actually existing situation in its unique complexity
Wonder - at the specific unexpected details, readiness to question previous habits and assumptions
Hope - for a ‘difference that makes a difference at some later time’ (Bateson);