Jp2 batch converter

Description

The jp2 files used by the Secondlife client, are actually j2k files. These can be encoded by image_to_j2k from openjpeg. The script identifies the image-resolution, and converts the image to a valid SL-resolution/aspect ratio. Subsequently it checks for jpg-files, and converts them to valid openjpeg input files if necessary. Valid openjpeg files are then converted to j2k fileformat, by image_to_j2k. At last the j2k file is renamed to jp2, and can be used as an secondlife texture. Use genassets.pl to generate an asset-set out of these files.

Code

#!/usr/bin/perl -s -U
# jp2batch.pl
# OpenSim jp2 texture preparation script
# Converts jpg/jpeg/bmp/tga files to valid jp2(jk2) files for SL
# Author: Phrearch
# Credits: Tedd1

$dirs=0;
$files=0;

sub ScanDirectory{
  my ($workdir) = @_;
  local (@names);
  $dirs++;
opendir(DIR, $workdir) or die "Unable to open $workdir:$!\n";
@names = readdir(DIR) or die "Unable to read $workdir:$!\n";
closedir(DIR);
	foreach my $tmpName (@names){
	my $name = $workdir."/".$tmpName;
		#\. or \.. in directory
		if ($tmpName =~ /^\.\.?$/){
		next;
		}	
		#directory
		if (-d $name){
		print "Entering directory $name\n";
		&ScanDirectory($name);
		next;
		}	
		#jpg or jpeg
		if ($name =~ /^(.*)\.(jpe?g|bmp|tga|tif|raw)$/){
		$rawname = $1;
		$ext = lc($2);
		$files++;
		print "\nProcessing $name...";
		&Convert($rawname,$ext);
		}
	}
 }
 
sub Convert{
my ($rawname, $ext) = @_;
my @imageid = split(/ /,`identify $rawname.$ext`); 
my @imageXY = split('x',@imageid[2]);
my $imageX = pop(@imageXY);
my $imageY = pop(@imageXY);
my $optX;
my $optY;
my $ar;
my $optar;


	#landscape or square, search for optimal X
	if ($imageX >= $imageY){
	$ar = sprintf("%.4f",$imageY / $imageX);
	$optar =  &supportedAR($ar);
	$optX = &supportedXY($imageX);
	$optY = $optX * $optar;
		#both aspectratio and resolution are correct
		unless(($imageX==$optRes) && ($ar==$optar)) {
		print "\nResizing ($imageX\xx$imageY => $optY\xx$optX)...";
		system(`convert -resize ${optX}x${optY}! $rawname.$ext $rawname.$ext &>/dev/null`);
		print "Done";
		}
	}
 
	#portrait, search for optimal Y
	else {
	$ar = sprintf("%.4f",$imageX / $imageY);
	$optar =  &supportedAR($ar);
	$optY = &supportedXY($imageY);
	$optX = $optY * $optar;
		#Needs conversion
		unless(($imageY==$optRes) && ($ar==$optar)) {
		print "\nResizing ($imageX\xx$imageY => $optX\xx$optY)...";
		system("convert -resize ${optX}x${opt}Y! $rawname.$ext $rawname.$ext &>/dev/null");
		print "Done";
		}
 	}
	if (($ext eq "jpg") || ($ext eq "jpeg")){
	print "\nConverting jpg to valid openjpeg format...";
	system("convert -format tga $rawname.$ext $rawname.tga &>/dev/null");
	system("rm $rawname.$ext &>/dev/null");
	print "Done";
	$ext="tga";
	}
print "\nCreating jp2 file...";
system("image_to_j2k -i $rawname.$ext -o $rawname.j2k -r 20,10,1 &>/dev/null");
system("mv $rawname.j2k $rawname.jp2 &>/dev/null");
system("rm $rawname.$ext &>/dev/null");
print "Done\n";
}

sub supportedAR{
my ($ar) = @_;
my @arReference=(1.0,0.5,0.25,0.125,0.0625);
my $arOptimal;
my $arDivTemp=1.0;
my $arDiv;
	#Get optimal aspect ratio
	foreach (@arReference){
	$arDiv=abs($ar-$_);
		if($arDiv < $arDivTemp) {
		$arDivTemp=$arDiv;
		$arOptimal=$_;
		}
	}
return $arOptimal;
}  

sub supportedXY{
my ($res) = @_;
my @resReference=(64.0,128.0,256.0,512.0,1024.0,2048.0);
my $resOptimal;
my $resDivTemp=4096.0;
my $resDiv;
	#Get optimal axis resolution
	foreach (@resReference){
 	$resDiv=abs($res-$_);
		if($resDiv < $resDivTemp) {
		$resDivTemp=$resDiv;
		$resOptimal=$_;
		}
	}
return $resOptimal;
} 

&ScanDirectory(".");
print "\nDirectories scanned:$dirs\nFiles processed:$files\n" ;

Usage

• Install OpenJPEG svn (if you have trouble compiling, you could try the binaries on their site)

svn co http://www.openjpeg.org/svn/trunk
cd trunk
mkdir bin
cd bin
cmake .. -DBUILD_EXAMPLES:BOOL=ON
make
make install

• Make sure that the binaries image_to_j2k and j2k_to_image can be executed from anywhere

• Put the code in a file named jp2batch.pl, and copy it to the root-directory where your jpg-wannabe-textures are. Call the script:

perl jp2batch.pl