#colour conversion

If there’s a theme over the last few post it’s re-invention. And the carpet industry is ripe for it: 400,000 tonnes of unwanted carpet is buried in UK landfill every year.

Isabel Webbhas decided thats where the rubys in the dust lie – she’s taking both domestic and industrial carpet waste and giving it her own unique twist through dying, tufting, embroidery and shearing to reveal new patterns…

Hier ist ein Zusammenschnitt aus Videos, das während dem Umfärbens unserer blauen Trommel entstanden ist. Als ich nach Infos diesbezüglich gesucht habe, musste ich leider ganz schön viel herumklauben und mir zusammendenken... Darum dachte ich, es wäre cool, ein Video zu machen, in dem andere alles sehen & nachvollziehen können, wenn sie sowas selbst ausprobieren wollen! Viel Spaß!

Die Trommel wurde umgefärbt um den Abschluss von Milena Albiez und Britta Wagemann (Plakatmaschine.de) zu drucken. Die beiden waren beim Umfärbeprozess eine super Hilfe! Danke!

- Helen

"One of the questions I have came to face earlier in my project is how precisely could I adjust a certain shade of colour to be either darker or lighter to my whim. Some of the earlier thought suggested I simply add or subtract a value from each of the R, G, B components. While it could serve suitably well enough for monochrome, that is not the type of colour I mostly operate in. Thus again, Google was to be for me. Most of the suggestions I came upon agreed on this one particular method. Here's what they said."

"Let there be light."

"Actually, I was kidding. Though the concept does involve light of some sort. It is though an derivative of an RGB color model called HSL that we'll achieve precisely just that."

"So the first question, What is RGB?"

"RGB, each abbreviates for Red, Green, Blue, describes what kind of light needs to be emitted to produce a given color. Light is added together to create form from out of the darkness. (RGB is an additive colour.) It was then from RGB that two other representations were designed, namely HSL and HSV. It is HSL, we'll focus upon."

"Why?"

"L... is for Lightness."

"I suppose you've already guessed out what I am about to do here. (For the code, there's already one written here."

"From RGB, convert the colour into its HSL representation. Adjust the lightness value, then convert it back."

From RGB to HSL

/** * Converts an RGB color value to HSL. Conversion formula * adapted from http://en.wikipedia.org/wiki/HSL_color_space. * Assumes r, g, and b are contained in the set [0, 255] and * returns h, s, and l in the set [0, 1]. * * @param Number r The red color value * @param Number g The green color value * @param Number b The blue color value * @return Array The HSL representation */ function rgbToHsl(r, g, b){ r /= 255, g /= 255, b /= 255; var max = Math.max(r, g, b), min = Math.min(r, g, b); var h, s, l = (max + min) / 2; if(max == min){ h = s = 0; // achromatic }else{ var d = max - min; s = l > 0.5 ? d / (2 - max - min) : d / (max + min); switch(max){ case r: h = (g - b) / d + (g < b ? 6 : 0); break; case g: h = (b - r) / d + 2; break; case b: h = (r - g) / d + 4; break; } h /= 6; } return [h, s, l]; }

From HSL to RGB