Arfunkel: Functions for Art

Creative Coding Amsterdam18 February 2016

Eelco den Heijer

Introduction

•Arfunkel : Art Functions

•Functions on Images

•Generative Art

•Building Blocks

•Not a Tool: Framework

Me

•Programmer (mainly Java), Creative Coder

•Many projects on Creative Coding

• PhD on Evolutionary Art (2013,CS,VU)

• Studio Heist

•Also like Music Technology (electronic music, generative music, coding…)

Functions on Images

create

filter

blend

split

terminate

Functions on Functions

•or: Higher Order Functions

• Repeat/ loop (e.g. kaleidoscope)

• If/then/else

• Etc.

blending pixels• each pixel consists of 3 components: R,G,B• RGB is a colour space or colour model• Colour space = way to organize or order colors• Well-known colour spaces: RGB, HSV/HSB, HSL,

CMYK, YIC, CIEXYZ, CIELUV,CIELAB etc.

Blending: how?• Blend 2 images:

• Iterate over all pixels (x,y):

• Pixel p1 from image 1, Pixel p2 from image 2:

• Take RGB from both pixels

• Convert to HSV (or any other colour space)

• apply function fi to each channel i (e.g. average, min, max, left, right, etc) : vi=fi(ci1,ci2); see next slide for more details

• Convert back to RGB

Example• Colour space = HSV

• Components c1,c2,c3=Hue, Saturation, Value

• functions: f1,f2,f3=min, max, avg

• New pixel:

• huenew=min(hue1,hue2)

• satnew=max(sat1,sat2)

• valnew=avg(val1,val2)

• Convert from hsv back to RGB

Recolouring• Changing the colours in an image

• Used for image repair, fixing lighting issues, or artistic purposes

• Several algorithms possible, often with source image and target image

• Channel shift algorithm

• Convert RGB to HSV (or any other colour space)

• Take value of each channel, shift predefined value

• Ensure you do not cross boundary values

RGB

HSV

CIELAB

Mirroring • Simple horizontal, vertical mirror

• Sort of Kaleidoscope effect

Misc

•Several standard, ‘bread and butter’ filters;

• Solarize

• Blur

• Posterize

• Image Segmentation

Workflow ex. 1

Get Image

Get Image

Blend Recolour Solarize

Workflow ex. 2

Get Image

Get Image

Blend

Recolour

MirrorLeft/Right

Recolour

Conclusions & Future work• First Scala, now Java 8

• Heavy use of ‘lambdas’

• Pretty flexible, still prototype

• More weird recolouring (colour transfer)

• Higher order functions

• Colouring (grayscale to colour)

• Grammar; Little Language (my own Processing)

• REPL: Read-Eval-Print Loop

Questions? @eelcodenheijer

Tumblr: eelcodenheijereelcodenheijer@gmail.com