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To have a good (near invisible) junction between two triangular zones means succeeding, with different lines boldness and angles, to cover the paper with the same proportions of colors. If it is visually good, it means that the drawing instrument is well calibrated, and that all the calculus were correct.
In my next drawing D65 n°6 I will have a lot of junctions like this one, the challenge will be to make them all as good as this one! :)
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TO EXPLORE WHAT YOU CAN SEE BELOW !!
below: the original picture used for the test, an image taken in Japan.
I spent the last few days, entire days, learning how to use the C++ programming language, first attending one hour particular lesson at home, then via internet (in particular by posting my problems on the great website stackoverflow.com) and finally today I succeeded creating a first version of what I wanted: a simple error-diffusion bitmap algorithm that I will now improve and reuse in my wallpaper project (or “Light Transformer v.3″, see v.2 here: Light Transformer 2)
That’s great, I’m happy – and tired – now :)
A grey color sample in mixed additive/subtractive color synthesis
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You might have heard of the “additive” and “subtractive” color syntheses at school or anywhere else before.
When I was an art student, the difference between the two syntheses of color was explained to me in terms of difference between “material colors” and “colored lights.” The two canonical examples were the computer screen’s RGB and the offset CMYK color systems.
I have never been satisfied by these explanations and examples. My fist-ever counter-argument was simple: a screen and an object under a light source both emit light in the direction of my eye, so why make a difference between two types of objects that both emit light?
How I abandoned subtractive colors
Since then, I have been trying to create a (material-) color process that would be as easy and as precise as the union of an image editor and of a computer’s screen, but on paper (see my series D65 studies, 2011-2013.)
In 2009, I decided to abandon the use of any transparent colored material (inks, watercolors, etc.) because there was for me no precise way to control the amount of material that I would put on the paper: if you put more ink it makes a thick layer when it dries, which appears darker than a thin layer.
Also, transparent inks produce quite unpredictable colors when you superimpose them…
Color averages (additive color) on paper
To control additive color synthesis is a much simpler process: imagine yourself with a piece of white paper and a opaque black paint, if you can cover almost exactly 1/2 of the paper with small black dots, black lines, a checkerboard or anything that diffuses evenly enough the black on the paper, the resulting color of this object – optically – will be in-between black and white, namely a grey optically made of 1/2 of these white and black materials.
Such a mixture has a simple meaning, but how would you find a 1:1 mixture of black and white if you were mixing paints? What would 1:1 mean? Without a model of human vision, nothing.
Magnified view of the 1st picture : it’s hard to see but there are 8 colors
Combining addition and subtraction
The advantage of using opaque colors was the easiness of creating an additive color process on paper (making color averages.) However, if we possess a tool that can pour on paper transparent colors evenly, we can include the transparency of the colors in the process. A true mixed process is then created, with 3 primaries on white, we get 8 colors already.
Of course, this is not any different than the traditional quadri offset process!
If we already measured the colors resulting when superimposing the primaries, we can predict the appearance of such color-mixtures with basic equations, where 3 variables x, y, z, refer to the amounts of the 3 primaries (tartrazine yellow, quinacridone magenta, phtalocyanine cyan)
However, it seems quite unstable for now and much harder to calibrate than my previous additive process.
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The problem was: the plotter makes dots from left to right, line by line, then goes to next line, etc.
It was a problem because one could see these lines and their limits/visual artefacts, when the pen’s paint flow slightly rises up or slows down.
How to solve that? I just programmed the drawing such as every point is made in a random order, and then: magic! everything disappears (see the video).