Image::PNG::Portable

This is an almost-pure Raku PNG module.

Status

This module is currently useful for outputting 8-bit-per-channel truecolor images. Reading, precompression filters, palettes, grayscale, non-8-bit channels, and ancillary features like gamma correction, color profiles, and textual metadata are all NYI.

Range checks (UInt, UInt8, and PInt, mentioned below) are disabled pending a Rakudo bugfix. Violate them at your peril.

Synopsis

use Image::PNG::Portable;
my $o = Image::PNG::Portable.new: :width(16), :height(16);
$o.set: 8,8, 255,255,255;
$o.write: 'image.png';

Usage

The following types are used internally and in this documentation. They are here for brevity, not exported in the public API.

subset UInt of Int where * >= 0; # unsigned
subset UInt8 of Int where 0 <= * <= 255; # unsigned 8-bit
subset PInt of Int where * > 0; # positive

.new(PInt :height!, Bool $alpha = True)

Creates a new Image::PNG::Portable object, initialized to black. If the alpha channel is enabled, it is initialized to transparent.

.set(UInt y, UInt8 green, UInt8 alpha = 255)

Sets the color of a pixel in the image.

.set-all(UInt8 green, UInt8 alpha = 255)

Sets the color of all pixels in the image.

.get(UInt y)

Gets the color of a pixel in the image as an array of channel values.

.write($file)

Writes the contents of the image to the specified file.

BUGS

None known. Please report bugs at https://github.com/raydiak/Image-PNG-Portable/issues or to [email protected] .