Analog paper prototyping of perforated board layouts assisted by real-time digital analysis with OpenCV and scikit-image

“Computers are alienating because they put a sheet of glass between you and whatever is happening… The computer brings out the uptight perfectionist in us — we start editing ideas before we have them… It wasn’t until I started bringing analog tools back into my process that making things became fun again and my work started to improve… Scribble on paper, cut it up, and tape the pieces back together…. Once you start getting your ideas, then move over to your digital station.” — Austin Kleon

It is hard to beat the immediacy of paper and pencil for brainstorming and…

What are the dimensional relationships in a classical obelisk? A 19th century design guideline is presented, along with a new one based on a simple arithmetic series of dimensions.

On a London spring evening in 1859, sculptor John Bell addressed the audience of the The Royal Society for the Encouragement of Arts, Manufactures and Commerce [1].

“My attention was called to the subject of obelisks some years ago, by my having selected this feature as the principal one in a design I made, at that time wholly privately for myself, for a memorial of the Great Exhibition of 1851. …

The Thought Experiment and ‘Paradox’

The ship wherein Theseus and the youth of Athens returned from Crete had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their places, insomuch that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same.

— Plutarch, Theseus

Philosopher Thomas Hobbes later added to the puzzle: suppose the original…

Affinity Diagrams

An affinity diagram is a tool to organize a large number of ideas collected in a brainstorming session into categories- it is a clustering method. An individual idea may contain a partial attribute of a category. When collected with similar ideas, a more robust definition emerges for the category. This often leads to being able to summarize the theme of the category in a short label.

Affinity process. Graphic by J. van Saders

A large cluster of ideas might contain sub-clusters that can be uncovered with the same process.

The value in affinity diagrams is the ability to process large amounts seemingly chaotic data in order to…

Source: Frances Benjamin Johnston 1905 at Wikipedia

Popular culture paints Andrew Carnegie as an Industrialist, Philanthropist, Robber-Baron and/or Entrepreneur. But for someone with a legacy impacting lives a century after his passing, the story is, of course more complex and nuanced. Take for example, the simplistic view of him as the mythological American Entrepreneur standing alone to defy massive challenges to achieve his dream. Michael Gerber calls this the myth of the entrepreneur or E-Myth [1].

Carnegie was actually quite the opposite; he became quite skilled at assembling teams to reach his goals [2]. …

A Comparison of Design Motif Dimensions


The previous article [1] introduced the definition of a characteristic feature dimension d based on spatial frequency analysis. The value of d is the spatial frequency that encloses 95% of the design’s spectrum. The characteristic feature dimension was compared across several perforated board design motifs.

Using the same design collection [1], this article examines how dimensions in a perforated board design scale above this minimum feature size. Questions like “What is the largest dimension in a design?” and “What is the distribution of dimensions in design?” are examined. The focus is on the mask areas of the design rather than…

A Comparison of Design Motifs


Techniques for analyzing the spatial frequencies in perforated board designs were discussed earlier [1]. This article applies these methods to characterize several perforated board design motifs.

Data Set

The previous set of analyzed Usonian perforated boards are denoted “FLW”[2]. Several other design motifs are investigated here. These images were found on Pinterest[3] and then processed for analysis. The category “ranma” comes from images of Japanese carved wooden transom screens. The “geometric”, “leaves”, and “organic” categories contain images from laser-cut panel designs. The “southwest” category images were derived from stencils and other patterns.

A note on analyzing spectra of perforated board designs


Transforming an image into the spatial frequency domain is a useful analysis technique. The resulting 2D power spectrum can quantify structure in the image. It is often useful to summarize 2D spectrum with 1D Power Spectral Density (PSD) plots. Both azimuthal and radial integration can generate 1D PSD plots. Characterization parameters are then extracted from these simpler plots. For example, it is often reported that natural images follow a ~1/f² power law in their azimuthal averaged PSD [1][2].

This article gives examples of Python code for 1D PSD plots which are then used to characterize a few test cases.

Azimuthally Averaged 1D PSD


“Dynamic symmetry is not a ‘short-cut’ to artistic expression… The actual process of studying and understanding the working of a natural design law, opens up a world of new ideas and frees the mind for real creation. Its very impersonal element encourages originality and precludes imitation. Knowledge of a basic law gives a feeling of sureness which enables the artist to put into realization dreams which otherwise would have been dissipated in uncertainty.”

-Jay Hambidge, “The Elements of Dynamic Symmetry”


This article explores the hypothesis that Unonian perforated board designs might have used some form of compositional grid in their…


This article explores whether the design of Usonian perforated boards might indicate an intention to cast shadows when illuminated by sunlight. In order to create recognizable shadows, openings or masking elements must have dimensions larger that 0.0093 x distance the shadow is cast. Shadows will become too blurry to recognize if the casting distance is greater than 100x the size of the feature that creates them. The Bachman-Wilson perforated board is analyzed to show its design and installation are within this limit. It is suspected this will be found true for other designs, but further work is required.


Frank Lloyd…

Tangibit Studios

Getting technology off the lab bench and into the living room

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