The Semantics of Line Drawings III, Appointing a Representative

[ The Semantics of Line Drawings II, Information Deformation Theory | The Semantics of Line Drawings IV, Douglas Hofstadter's Metaphor for Translation ]

Here's a not very good picture taken from my bedroom window:

You can see that the walls of the houses are brick, and just about see the individual bricks. Suppose that you wanted to draw this in black and white. Drawing all the lines between the bricks would make the drawing look "busy", as would shading each brick to indicate its tonal value. So if you want to indicate that there are bricks in the wall, what do you do? One possibility is to apply a transformation that I call "appointing a representative".

You draw just a few patches of bricks, leaving the viewer's brain to fill in the rest. These patches are representatives for the rest of the bricks.

This transformation can be thought of as a two-step process. In the first step, draw all the bricks. Unfortunately, this overemphasises them relative to the rest of the drawing. So in the second, reduce the "brick level" until they are no more prominent than in the photo.

The Semantics of Line Drawings II, Information Deformation Theory

[ The Semantics of Line Drawings I | The Semantics of Line Drawings III, Appointing a Representative ]

An interesting aspect of the semantics of line drawings is what one might call Information Deformation Theory. Here's an example.

I was drawing people's hands from across Cornmarket Street, a wide shopping street in the centre of Oxford. From one side of Cornmarket, you can see the general shape of the hands of people on the other side, and the positions of some of the fingers if the light is favourable. My natural tendency is to try to draw all the fingers, with lines indicating the boundary of each. But this looks very wrong. Why?

It looks wrong, I think, for the same reason that I mentioned in one of the slides for my Thales talk: "Texture lines are often omitted". The slide showed a drawing from Christopher Hart's book How to Draw Cartoon Baby Animals. When drawing the face, Hart advises, draw ruffles of fur on the cheeks, but leave a large neutral space under the chin. This allows the eye to "rest" and stops the animal from looking too furry.

Similarly, cartoonists often draw only a few isolated patches of bricks in walls, as in this clip-art Great Wall of China:

Drawing the spaces between bricks or blocks as black lines overemphasises them relative to the original scene. And in my drawings of hands, drawing all the boundaries between fingers, even with a fineliner pen, would overemphasise them.

In other words, the medium — such as pen and ink — biases the information represented with it, and the artist must compensate by warping or deforming the drawing in some way. That's what I propose to write about in the next few posts.