Michal Migurski's notebook, listening post, and soapbox. Subscribe to this blog. Check out the rest of my site as well.

Jun 30, 2008 12:57am

the map is here for you to use

Suddenly I care about OpenStreetMap, all over again.

OSM is a cognitive surplus project whose ultimate goal is a CC-licensed, crowd-sourced vector map of the world, competitive with Google, NavTeq, TeleAtlas and other geographic data providers. The project has been in motion for the past four years, with especially active support in Germany and the UK and a recent TIGER/Line infusion for the United States.

Why is OSM interesting? Having watched Oakland transition from the raw TIGER/Line data import to a more refined, watched-over state (compare the visual appearance of nearby Concord to West Oakland for a sense of the difference), I'm starting to think that the main advantage of OSM might be in the kinds of details overlooked by the larger mapping agencies, and in a certain unevenness of coverage indicating which places are cared-for. Over the past few weeks, I've spent a few hours drawing in parks near where I live:



The difference isn't exactly earth shaking, but it does begin to introduce a feeling of reality into the rendered image. Raw streets are probably accurate enough for basic driving purposes. Parks fill in details, and promise that what you're seeing bears some relationship to what you'll find if you were to actually visit.

Google Maps' coverage of West Oakland is still substantially wrong, especially outside the 880 loop in the Port Of Oakland territory. They've still got Army Base roads that no longer exist, and miss Middle Harbor Shoreline Park completely. Small potatoes until you think about the effort expended to convert port and military territory to more civic uses in a part of town known more for its asthma-aggravating emissions than its amenities.

The potential for detail represented by OSM extends down into territories more conventionally associated with local-type business listings. Tagging your input with "amenity: pub" causes a little amber pint glass to be rendered to the main map, betraying the beer preference of OSM's British founders and their aims for a richer mapping experience:

What's really going on here is that a particular historical wall is being chipped away. The understanding fostered by the Googles and NavTeqs of the world is that map data is an unchanging (or at least unchangeable) base layer, with transient information such as directions or grocery stores layered over it. What's interesting about OSM is the edit button, the thing where you get to apply your own local knowledge about your area for others to benefit from. This is where I think OSM is finding its niche as a credible alternative for those who need maps. For example, we decided to go with a Virtual Earth base layer for our Oakland Crimespotting project, to expedite its launch at a busy time. Almost a year later, we may suddenly find that OSM's data for Oakland has reached sufficient quality for use in a real application, one where we might (for example) choose to mark and render liquor stores, schools, or police stations right on the map layer for added crime data context. We don't need nationwide coverage, but we do need excellent local coverage and are probably willing to do the footwork to improve an area for our own immediate benefit.

The kind of custom rendering implied by what I'm describing is starting to become a sane possibility, with software like Mapnik making available high quality visual rendering of geographic information. Paul Smith of EveryBlock described its basic use in an ALA article a few months back, while we've been using the software to a point where we can confidently predict its blackbox behavior and really start to customize its output.

Annoyingly, OSM is still finding its technical footing. Despite an excellent API, changes made to the underlying data take a few days to appear in the officially rendered tile sets, and the editing tools are still a bit dorky for general consumption. This may not ultimately matter as far as the basic idea is concerned - momentum behind the project is sufficient for it to gain a foothold in certain key metropolitan areas, and supports specialist efforts like derived cycling or topographical maps. I can imagine other specialist needs like motocross, fishing, bed and breakfasts, etc. taking over the care and feeding of certain kinds of map data. It's easy to forget that familiar road maps were once a hobbyist endeavor as well.

I'm interested in a near future where the native advantage of commercial mapping agencies becomes a liability. Might there be a situation where it's no longer economically feasible for company representatives to drive every street when there might be equally-good input from crowds of motivated participants? At some point, the quality of the basic street grid becomes Good Enough, and the kinds of details noticed only by locals takes on greater importance.

Jun 12, 2008 1:48am

blog all dog-eared pages: art and illusion

Almost three months have passed since my last book post, and I've been having terrible luck with non-fiction lately. A chance encounter with bkkeepr reminded me that E.H. Gombrich's Art And Illusion had been sitting on my recently-cleaned desk since April or so.

Gombrich is one of those towering academic figures whose Story Of Art dominates first year art history courses. This book is more specific, tracing the evolution of art and visual perception, arguing for a definition of style and representation that moves from primitive schemata to modern responses to light and geometry.

Page 78, on correctness and style:

To say of a drawing that it is a correct view of Tivoli does not mean, of course, that Tivoli is bounded by wiry lines. It means that those who understand the notation will derive no false information from the drawing - whether it gives the contour ina few lines or picks out "every blade of grass" as Richter's friends wanted to do. ... Styles, like languages, differ in the sequence of articulation and in the number of questions they allow the artist to ask; and so complex is the information that reaches us from the visible world that no picture will ever embody it all. That is not due to the subjectivity of vision but to its richness.

Page 106, on Egyptian art and eternity:

...what does seem likely is that picture cycles and hieroglyphs, representations and inscriptions, were more interchangeable in Egyptian eyes than they are for us. ... Mrs. Frankfort concludes that "the rendering of a typical timeless event means both a timeless presence and a source of joy for the dead." But if they are right who see the origin of these typical scenes in pictograph renderings of the round of the seasons, Mrs. Frankfort's analysis might carry even greater weight. For where would it be more meaningful to re-present the cycle of the year in typical symbolic images than on the walls of a tomb that is meant to impart eternity to its inmate? If he could thus "watch" the year come round and round again, the passage of time, the all-consumer, would be annihilated for him. The sculptor's skill would have anticipated and perpetuated the recurrent cycle of time, and the dead could thus watch it forever in that timeless cycle of which Mrs. Frankfort speaks. In this conception of representation, "making" and "recording" would merge. The images would represent what was and what will always be and would represent them together, so that time would come to a stop in the simultaneity of a changeless now.

Page 120, on the Greek invention of art:

There is a painting on one of the walls of a Pompeian house that reflects this motif. It is not a great work of art, and the same criticism applies to many other copies of Greek works found in Italy and elsewhere. But such criticism has tended to obscure the most astounding consequence of the Greek miracle: the fact that copies were ever made at all to be displayed in the houses and gardens of the educated. For this industry of making reproductions for sale implies a function of the image of which the pre-Greek world knew nothing. The image has been pried loose from the practical context for which it was conceived and is admired and enjoyed for its beauty and fame, that is, quite simply within the context of art. ... It may sound paradoxical to say that the Greeks invented art, but from this point of view, it is a mere sober statement of fact.

Page 132, on the Renaissance and schemata:

Leonardo was obviously dissatisfied with the current method of drawing trees. He knew a better way. "Remember," he taught, "that whenever a branch divides, the stem grows correspondingly thinner, so that, if you draw a circle round the crown of the tree, the sections of every twig must add up to the thickness of the trunk." I do not know if this law holds. I do not think it quite does. But as a hint on "how to draw trees," Leonardo's observation is invaluable. By teaching the assumed laws of growth he has given the artist a formula for constructing a tree - and so he can feel like the creator, "Lord and Master of all things," who knows the secrets of nature and can "make" trees as he hoped to "make" a bird that would fly. I believe what we call the Renaissance artists' preoccupation with structure has a very practical basis in their needs to know the schema of things. For in a way our very concept of "structure," the idea of some basic scaffolding or armature that determines the "essence" of things, reflects out need for a scheme with which to grasp the infinite variety of this world of change.

Pages 147-148, on active perception:

We hear a lot about training the eye or learning to see, but this phraseology can be misleading if it hides the fact that what we can learn is not to see but to discriminate. If seeing were a passive process, a registration of sense data by the retina as a photographic plate, it would indeed be absurd for us to need a wrong schema to arrive at a correct portrait. But every day brings new and startling confirmation form the psychology laboratories that this idea, or ideal, of passivity is quite unreal. "Perception," it has recently been said, "may be regarded as primary the modification of an anticipation." It is always an active process, conditioned by our expectations and adapted to situations. Instead of talking of seeing and knowing, we might do a little better to talk of seeing and noticing. We notice only when we look for something, and we look when our attention is aroused by some disequilibrium, a difference between our expectation and the incoming message.

Page 162, on seeing things from a distance:

"The Athenians intending to consecrate an excellent image of Minerva upon a high pillar, set Phidias and Alcamenes to work, meaning to chuse the better of the two. Alcamenes being nothing at all skilled in Geometry and in the Optickes made the goddesse wonderfull faire to the eye of them that saw her hard by. Phidias on the contrary ... did consider that the whole shape of his image should change according to the height of the appointed place, and therefore made her lips wide open, her nose somewhat out of order, and all the rest accordingly ... when these two images were afterwards brought to light and compared, Phidias was in great danger to have been stoned by the whole multitude, untill the statues were at length set on high. For Alcamenes his sweet and diligent strokes beeing drowned, and Phidias his disfigured and distorted hardnesse being vanished by the height of the place, made Alcamenes to be laughed at, and Phidias to bee much more esteemed."

Pages 174-175, on economy:

But no tradition of art had a deeper understanding of what I have called the "screen" than the art of the Far East. Chinese art theory discusses the power of expressing through absence of brush and ink. "Figures, even though painted without eyes, must seem to look; without ears, must seem to listen. ... There are things which ten hundred brushstrokes cannot depict but which can be captured by a few simple strokes if they are right. That is truly giving expression to the invisible." The maxim into which these observations were condensed might serve as a motto of this chapter: "i tao pi pu tao - idea present, brush may be spared performance."

Pages 247-248, on primitivism:

Because of this gravitation toward the schematic or "conceptual," we have a right to speak of "primitive" modes of representation, modes, that is, which assert themselves unless they are deliberately counteracted.
It is easy to show that these modes have their permanent and roughly predictable features which distinguish them from Constable's approach. I have asked a child of eleven to copy a reproduction of Constable's Wivenhoe Park. As expected, the child translated the picture into a simpler language of pictorial symbols. The copy is really a tidy enumeration of the principal items of the picture, particularly those which would interest a child - the cows, the trees, the swans on the lake, the fence, the house behind the lake. What has been missed, or much underrated, are the modifications which these classes of things undergo when seen from different angles or in different light. The house, therefore, is much larger than in Constable's picture, and the swans are gigantic. The boats and bridges are seen from above in that "conceptual" maplike mode which brings out the characteristic features.

Page 268, towards a reductive definition of art history:

...it is not hard to show that the vocabulary which Constable used for the portrayal of these East Anglian scenes comes from Gainsborough. ... But if this is true, are we not led into what philosophers call an infinite regress, the explanation of one thing in terms of an earlier which again needs the same type of explanation? If Constable saw the English landscape in terms of Gainsborough's paintings, what about Gainsborough himself? We can answer this. Gainsborough saw the lowland scenery of East Anglia in terms of Dutch paintings which he arduously studied and copied. We have his drawing after Ruisdael, and we know that it was this vocabulary which he applied to the rendering of his own idyllic woodland scenes. And where did the Dutch get their vocabulary? The answer to this type of question is precisely what is known as the "history or art." All paintings, as Wolfflin said, owe more to other paintings than they owe to direct observation.

Page 279, on learning:

In all these cases there is the same need to proceed by experiment, and for the same reason: the filing system of our minds works so differently from the measurements of science. Things objectively unlike can strike us as very similar, and things objectively rather similar can strike us as hopelessly unlike. There is no way of finding out except by trial and error, in other words, through painting. I believe that the student of these inventions will generally find a double rhythm which is familiar from the history of technical progress but which has never yet been described in detail in the history of art - I mean the rhythm of lumbering advance and subsequent simplification. Most technical inventions carry with them a number of superstitions, unnecessary detours which are gradually eliminated through short cuts and a refinement of means.
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