reverse-interlace-adam7 ( 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 arrays grouping io.encodings.binary
io.streams.byte-array kernel math sequences ;

IN: images.png

:: reverse-interlace-adam7
    ( byte-array loading-png -- byte-array )
    byte-array binary <byte-reader>
    :> ba loading-png height>> :> height loading-png width>>
    :> width loading-png bit-depth>> :> bit-depth loading-png
    png-components-per-pixel :> #bytes! width height * f <array>
    width <groups> :> image bit-depth 16 =
    [ #bytes 2 * #bytes! ] when 0 :> row! 0 :> col! 0 :> pass!
    [ pass 7 < ] [
        ba loading-png pass read-adam7-subimage #bytes <groups>
        pass starting-row nth row! pass starting-col nth col! [
            [ row col f f ] dip image visit
            col pass col-increment nth + col! col width >= [
                pass starting-col nth
                col! row pass row-increment nth + row!
            ] when
        ] each pass 1 + pass!
    ] while image concat B{ } concat-as ;