Bitmap/Read a PPM file: Difference between revisions
→{{header|Perl 6}}: Add perl 6 example
m (Adjust color element names.) |
Thundergnat (talk | contribs) (→{{header|Perl 6}}: Add perl 6 example) |
||
Line 1,005:
exit 0;</lang>
=={{header|Perl 6}}==
{{works with|Rakudo|2017.09}}
Uses pieces from [[Bitmap#Perl_6| Bitmap]], [[Bitmap/Write_a_PPM_file#Perl_6| Write a PPM file]] and [[Grayscale_image#Perl_6| Grayscale image]] tasks. Included here to make a complete, runnable program.
<lang perl6>class Pixel { has UInt ($.R, $.G, $.B) }
class Bitmap {
has UInt ($.width, $.height);
has Pixel @.data;
}
role PGM {
has @.GS;
method P5 returns Blob {
"P5\n{self.width} {self.height}\n255\n".encode('ascii')
~ Blob.new: self.GS
}
}
sub load-ppm ( $ppm ) {
my $fh = $ppm.IO.open( :enc('ISO-8859-1') );
my $type = $fh.get;
my ($width, $height) = $fh.get.split: ' ';
my $depth = $fh.get;
Bitmap.new( width => $width.Int, height => $height.Int,
data => ( $fh.slurp.ords.rotor(3).map:
{ Pixel.new(R => $_[0], G => $_[1], B => $_[2]) } )
)
}
sub grayscale ( Bitmap $bmp ) {
$bmp.GS = map { (.R*0.2126 + .G*0.7152 + .B*0.0722).round(1) min 255 }, $bmp.data;
}
my $filename = './camelia.ppm';
my Bitmap $b = load-ppm( $filename ) but PGM;
grayscale($b);
'./camelia-gs.pgm'.IO.open(:bin, :w).write: $b.P5;</lang>
See [https://github.com/thundergnat/rc/blob/master/img/camelia.png camelia], and [https://github.com/thundergnat/rc/blob/master/img/camelia-gs.png camelia-gs] images. (converted to .png as .ppm format is not widely supported).
=={{header|Phix}}==
| |||