Color Utilities

Version: 5.2.1

Color Utilities

(require (planet dsheap/color-utils:1:=2))

These are some convenience tools to transform images in the 2htdp/image library. The convenience consists of producing new colors by changing a single intensity by name, and a for-like comprehension for images.

(<-component band old) → (color)
band : symbol?
old : color?

Produces band portion of old’s color.

(+color component val col) → (color)
  component : symbol?
  val : number?
  col : color?

Produces color based on old, but using intensity val in band corresponding to component.

(green+color val col) → (color)
val : number?
col : color?

Produces color based on col, but with the green intensity to val.

Example:
> (green+color 10 (color 1 2 3 4))
(color 1 10 3 4)

(for/image ([id image-expr] ...)
body ...+)

Produce new image by binding id to each element of image-expr’s color-list in turn.