Class 36: Algorithmic Art

Held: Friday, 4 April 2003

Summary: Today we consider a number of ways to use algorithms to generate or modify art.

Related Pages:

• EBoard.
• Online Class Images.
• circles.scm, the code we wrote yesterday (with some variations).
• art.scm, some useful code for today's lab.
• Lab on Algorithmic Art.

Assignments

• Read Output in Scheme.
• Read Input in Scheme.

Notes:

• We may have admitted students visiting today.
• I know that there are a number of questions on exam 2. We'll go over them for awhile.
• We can hold today's class in one of two ways: We can do a normal lab session or we can use the startegy we used on Wednesday.

Overview:

• About Images.
• Algorithmically generating and modifying images.
• Lab.

About Images

• Each image that the Gimp creates is effectively just a two-dimensional grid of color values.
• Hence, we can do interesting things using those color values.
  • We can generate those color values using some formula.
  • We can modify those color values using some formula.
  • We can move those color values around.
• I call the use of algorithms to accomplish those and similar purposes algorithmic art.
• I've built a number of procedures to help with those purposes
• The procedure (gsfu-create-image width height func) creates a new image of the specified width and height by applying func at every position.
  • func takes x and y as parameters and returns a color value (list of red, green, blue)
• The procedure (gsfu-load-image filename) loads an image.
  • It returns a list of image-id and layer-id.
  • You can find someone's face to use by going to the online course images.
• The procedure (gsfu-map-image image layer func) creates a new image by applying func at ever position.
  • func should be a function from color to color.
• The procedure (gsfu-map-coordinates image layer func) creates a new image by applying func at every position. (Do you notice a trend here?)
  • func takes many too many parameters for me to mention here.

Lab

• Do the lab.
• Be prepared to reflect.