Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked
 
PerlMonks  

Re: working with png data

by marioroy (Vicar)
on Sep 10, 2019 at 13:42 UTC ( #11105966=note: print w/replies, xml ) Need Help??


in reply to working with png data

Greetings,

Running parallel is possible for both examples. The latter makes use of relay (for orderly) and gather capabilities in MCE.

First Example

use strict; use warnings; use GD::Simple; use MCE::Map; my $png = GD::Image->newFromPng('test.png'); my ($width,$height) = $png->getBounds; MCE::Map->init( max_workers => 4 ); my @sw = mce_map { my ($y,$str) = ($_,''); for my $x (0..$width - 1) { $str .= getPixel($x,$y); } $str; } 0..$height - 1; MCE::Map->finish(); # print $_, "\n" for @sw; sub getPixel { my ($index) = $png->getPixel($_[0],$_[1]); my ($r,$g,$b) = $png->rgb($index); my $p = ($b > 128 || $r > 128) ? 0 : 1; return $p; }

Second Example

use strict; use warnings; use GD::Simple; use MCE; my $png = GD::Image->newFromPng('test.png'); my ($bx,$by) = $png->getBounds; my @col; # foreground colors for (0..$png->colorsTotal) { my ($r,$g,$b) = $png->rgb($_); push (@col,$_) unless ($b>128 || $r>128); } my $pdata = ''; MCE->new( max_workers => 4, chunk_size => 1, input_data => \@col, init_relay => 1, # loads MCE::Relay gather => sub { # this runs inside the parent $pdata |= $_[0]; }, user_func => sub { # run parallel my $val = ~$png->wbmp($_); # send the val to the parent process # relay makes it run serially and orderly MCE::relay { MCE->gather($val); }; } )->run(); our $zlen = int(($bx + 7) / 8); # number of Bytes per line my $pos = 6; my $y = 0; # position after Header of WBMP my @sw; while ($pos < length($pdata)) { $sw[$y] = ''; for (1..$zlen) { # convert binary data into string $sw[$y] .= sprintf("%08b",ord(substr($pdata,$pos++,1))); } # print $sw[$y], "\n"; $y++; }

The examples run well. Output matches the OP's non-parallel demonstrations.

Regards, Mario

Replies are listed 'Best First'.
Re^2: working with png data
by Anonymous Monk on Sep 10, 2019 at 19:52 UTC
    Thanks. Thats also a cool idea ......

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://11105966]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others musing on the Monastery: (6)
As of 2019-11-13 17:27 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Strict and warnings: which comes first?



    Results (74 votes). Check out past polls.

    Notices?