scale-greyscale ( byte-array loading-png -- byte-array' )

Vocabulary

images.png

Inputs

byte-array	an object
loading-png	an object

Outputs

byte-array'

an object

Definition

USING: accessors assocs combinators grouping kernel math
sequences ;

IN: images.png

: scale-greyscale ( byte-array loading-png -- byte-array' )
    bit-depth>> {
        { 8 [ ] }
        { 16 [ 2 group [ swap ] assoc-map B{ } concat-as ] }
        [ scale-factor [ * ] curry B{ } map-as ]
    } case ;