HI ! I want to add an APP segment in a jpg image with the Image::MetaData::JPEG module.

The following code add an APP2 segment inside the jpg, but it seems to be empty as it only add \0xffe200002 in the file, which means: an APP2 segment (\0xffe2) of length 2 (\0x0002) (the marker plus the length's length = 2, basically an empty segment).

perl run.pl test.jpg 

use strict; use warnings;
use Image::MetaData::JPEG;
use Image::MetaData::JPEG::Record;
use Image::MetaData::JPEG::data::Tables
    qw(:JPEGgrammar :Endianness :RecordTypes);

use Data::Dumper;

#read the image filname from the command line arguments
my $file = new Image::MetaData::JPEG($ARGV[0]);

#add MP header information in the APP2 segment in the image
my $buffer;
my $segref = new Image::MetaData::JPEG::Segment('APP2', $buffer, 'NOPA
+RSE');

my $head = "MPF0";
my $recref = $segref->store_record('MP_HEADER', $LONG, \$head, 1);
print Dumper $segref;

$file->insert_segments($segref);

#save 
$file->save('tmp1.jpg');

[download]

Output 

$VAR1 = bless( {
                 'dataref' => \'',
                 'endianness' => undef,
                 'error' => undef,
                 'records' => [
                                bless( {
                                         'values' => [
                                                       1297106480
                                                     ],
                                         'extra' => undef,
                                         'key' => 'MP_HEADER',
                                         'type' => 4
                                       }, 'Image::MetaData::JPEG::Reco
+rd' )
                              ],
                 'name' => 'APP2'
               }, 'Image::MetaData::JPEG::Segment' );

[download]

How can I add a segement in a JPG with this module, how to use the insert_segments function properly ? especially the $buffer variable. thanks !

In reply to Add a segment in a JPG image with Image::MetaData::JPEG by neoldschool

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