Are you sure that $image->LoadFile(...) can take an IO::Scalar object?

Maybe try instead

open ICON, '<', \$icon_data or die $!;
...
$image->LoadFile( \*ICON, wxBITMAP_TYPE_ANY );
[download]

(lexical file handles might be ok, too — the ->LoadFile( \*FH, ...) syntax is just gleaned from one of the test files that come with Wx)

So, I've tried your proposal:

open ICON, '<', \$icon_data or die $!;
my $image = Wx::Image->new();
$image->LoadFile( \*ICON, wxBITMAP_TYPE_ANY );
$images_sm->Add( Wx::Bitmap->new($image, -1) );
[download]

The result were errors like this: "Can't load image from file 'Wx::Image=SCALAR(0x33094dc)': file does not exist. Couldn't add an image to the image list."

Are you sure that $image->LoadFile(...) can take an IO::Scalar object?
No, I am not. I just adapted this trick from videobox (sorry, there is no browsable CVS there, you need to look into the released .zip, in dir VBR/RES.pm, this app's resource lib), where it sais:

package VBR::RES;


# WARNING This file was automatically created by mkres.pl
# Any changes will be lost!

use MIME::Base64;
use FindBin;
use Carp;

my %res=();

# Toolbar button bitmaps must be 16x15 256 colors!

sub GetResource {
    my($name)=@_;
    
    $resname=lc($name);
    $resname =~ s/\\/\//g;
    if (defined $res{$resname}) {
        return $res{$resname};
    } else {
        open(FILE,"$FindBin::RealBin/$name") or die $!;
        binmode(FILE);
        my $data=join('',<FILE>);
        warn("Read ".length($data)." bytes from file: $FindBin::RealBi
+n/$name\n");
        return $data;
    }
}


sub OpenResource {
    my($name)=@_;

    use IO::Scalar;
    
    my $data = GetResource($name);
        return IO::Scalar->new( \$data );
}


sub GetImage {
    my($name)=@_;
    
    use Wx qw( wxBITMAP_TYPE_BMP );

    my $file = OpenResource($name);
    my $image = Wx::Image->new();
    $image->LoadFile( $file, wxBITMAP_TYPE_BMP );
    close($file);
    return $image;
}


sub GetBitmap {
    my($name)=@_;

    return Wx::Bitmap->new(GetImage($name));
}

    
Wx::InitAllImageHandlers();    
my $resname='';
while (<DATA>) {
    if (/^$/) {
        undef $resname;
    } elsif (/^@(.*)/) {
        $resname=lc($1);
        $resname =~ s/\\/\//g;
    } elsif ($resname) {
        $res{$resname}.=decode_base64($_);
    }    
}
close(DATA);


1;

__DATA__


@vbr/bitmaps/add.bmp
Qk0mBQAAAAAAADYEAAAoAAAAEAAAAA8AAAABAAgAAAAAAPAAAAASCwAAEgsAAAAAAAAAAA
+AAAAAA
AAAAgAAAgAAAAICAAIAAAACAAIAAgIAAAMDAwADA3MAA8MqmAAAgQAAAIGAAACCAAAAgoA
+AAIMAA
ACDgAABAAAAAQCAAAEBAAABAYAAAQIAAAECgAABAwAAAQOAAAGAAAABgIAAAYEAAAGBgAA
+BggAAA
YKAAAGDAAABg4AAAgAAAAIAgAACAQAAAgGAAAICAAACAoAAAgMAAAIDgAACgAAAAoCAAAK
+BAAACg
YAAAoIAAAKCgAACgwAAAoOAAAMAAAADAIAAAwEAAAMBgAADAgAAAwKAAAMDAAADA4AAA4A
+AAAOAg
AADgQAAA4GAAAOCAAADgoAAA4MAAAODgAEAAAABAACAAQABAAEAAYABAAIAAQACgAEAAwA
+BAAOAA
QCAAAEAgIABAIEAAQCBgAEAggABAIKAAQCDAAEAg4ABAQAAAQEAgAEBAQABAQGAAQECAAE
+BAoABA
QMAAQEDgAEBgAABAYCAAQGBAAEBgYABAYIAAQGCgAEBgwABAYOAAQIAAAECAIABAgEAAQI
+BgAECA
gABAgKAAQIDAAECA4ABAoAAAQKAgAECgQABAoGAAQKCAAECgoABAoMAAQKDgAEDAAABAwC
+AAQMBA
AEDAYABAwIAAQMCgAEDAwABAwOAAQOAAAEDgIABA4EAAQOBgAEDggABA4KAAQODAAEDg4A
+CAAAAA
gAAgAIAAQACAAGAAgACAAIAAoACAAMAAgADgAIAgAACAICAAgCBAAIAgYACAIIAAgCCgAI
+AgwACA
IOAAgEAAAIBAIACAQEAAgEBgAIBAgACAQKAAgEDAAIBA4ACAYAAAgGAgAIBgQACAYGAAgG
+CAAIBg
oACAYMAAgGDgAICAAACAgCAAgIBAAICAYACAgIAAgICgAICAwACAgOAAgKAAAICgIACAoE
+AAgKBg
AICggACAoKAAgKDAAICg4ACAwAAAgMAgAIDAQACAwGAAgMCAAIDAoACAwMAAgMDgAIDgAA
+CA4CAA
gOBAAIDgYACA4IAAgOCgAIDgwACA4OAAwAAAAMAAIADAAEAAwABgAMAAgADAAKAAwADAAM
+AA4ADA
IAAAwCAgAMAgQADAIGAAwCCAAMAgoADAIMAAwCDgAMBAAADAQCAAwEBAAMBAYADAQIAAwE
+CgAMBA
wADAQOAAwGAAAMBgIADAYEAAwGBgAMBggADAYKAAwGDAAMBg4ADAgAAAwIAgAMCAQADAgG
+AAwICA
AMCAoADAgMAAwIDgAMCgAADAoCAAwKBAAMCgYADAoIAAwKCgAMCgwADAoOAAwMAAAMDAIA
+DAwEAA
wMBgAMDAgADAwKAA8Pv/AKSgoACAgIAAAAD/AAD/AAAA//8A/wAAAP8A/wD//wAA////AA
+cHBwcH
BwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcAAAAAAAcHBwcHBwcHBwcAAPn5+Q
+AABwcH
BwcHBwcA+fn5+fn5+QAHBwcHBwcHAPn5+QD5+fkABwcHBwcHAPn5+fkA+fn5+QAHBwcHBw
+D5+QAA
AAAA+fkABwcHBwcA+fn5+QD5+fn5AAcHBwcHBwD5+fkA+fn5AAcHBwcHBwcA+fn5+fn5+Q
+AHBwcH
BwcHBwAA+fn5AAAHBwcHBwcHBwcHBwAAAAcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBw
+cHBwcH
BwcHBwcHBw==
(snip)
[download]


Is there some magic in VBR/RES.pm's routine nesting? And: the maturity of the videobox app tells me there must be some nasty bug in my routine... Anyone objecting?

How does it fail? What error do you get?

Actually, it just silently doesn't work. No errors, but the images do not show up in my ListCtrl.
Wrong memory. A new try showed that it produces the same error as above, the "Can't load image from file 'Wx::Image=SCALAR(0x33094dc)': file does not exist." error.
(BTW: is this the Wx::Image or Wx::Bitmap constructor failing?)

Why not create a self contained example which demonstrates your problem?

    Wx::InitAllImageHandlers();
    my $bmp = Wx::Bitmap->new("$_", wxBITMAP_TYPE_GIF);

    my $ok = $bmp->SaveFile("$fname.xpm", wxBITMAP_TYPE_XPM);

    open(my $dat, "$fname.xpm") || die("Could not open file! $fname.xp
+m $!");
     my @raw_data=<$dat>;
    close($dat); 

    my @filtered;
    for(@raw_data){
        next if $_ =~ /^\/\*/;
        next if $_ =~ /^static/;
        next if $_ =~ /^\}/;

        $_ =~ s/\@/\\@/g;
        $_ =~ s/\$/\\\$/g;
        $_ =~ s/\&/\\&/g;
        $_ =~ s/\%/\\%/g;

        push(@filtered,$_);
    }

    my $data = join('',@filtered);
    $vars .= "\$images->{$fname}\t= [". $data ."];\n\n";
[download]

What's wrong? Nothing. :)

Here is a working example (at least on my system), of an embedded icon. The icon data is from the tkIcons file, part of the Tk::ToolBar module.

Regards, Stefan