鐃緒申鐃獣わ申鐃緒申鐃緒申鐃緒申鐃緒申鐃祝￥申呂匹鐃緒申鐃緒申鐃�

404 Blog Not Found:Ajax - 鐃叔￥申鐃緒申鐃緒申 via PNG
鐃夙わ申鐃宿わ申鐃緒申鐃緒申鐃緒申鐃緒申的鐃緒申鐃緒申鐃暑。

Demo 0

鐃緒申鐃緒申鐃緒申鐃緒申鐃緒申鐃祝ワ申鐃藷コ￥申鐃緒申鐃緒申鐃塾ワ申鐃緒申鐃緒申鐃緒申鐃緒申鐃宿わ申鐃緒申鐃緒申鐃緒申任鐃緒申襦�







$('#demo0 input').click(function(){
    $('#demo0dst').text(showTextInPNG($('#demo0img').get(0)));
});






Perl鐃叔テワ申鐃緒申鐃夙わ申鐃緒申个鐃緒申鐃緒申鐃緒申鐃緒申鐃緒申鐃緒申匹楼焚鐃緒申里箸鐃緒申蝓�


#!/usr/bin/env perl
use strict;
use warnings;
use Imager;
use autodie;

my $img = Imager->new();
$img->read( file => shift ) or die $img->errstr;
$img->write( data => \my $pnm, type => 'pnm' ) or die $img->errstr;
my $hdr = do {
    $pnm =~ s/((?:[^\n]+\n){4})//;
    $1;
};
my @pnm = map { ord } split //, $pnm;
my $txt = '';
for my $i (0..+@pnm / 3){
    my $ord = (($pnm[3*$i]   & 0b00000111)<<5)
            + (($pnm[3*$i+1] & 0b00000011)<<3)
            +  ($pnm[3*$i+2] & 0b00000111);
    last if ! $ord;
    $txt .= chr $ord;
}
print $txt;



鐃宿わ申鐃緒申辰討鐃緒申?


鐃竣わ申鐃緒申法鐃�24bit鐃緒申鐃初ー鐃塾醐申鐃緒申鐃緒申鐃緒申16bit(RGB=565)鐃祝醐申鐃緒申鐃緒申鐃緒申鐃緒申如鐃緒申鐃緒申鐃緒申鐃�8bit鐃緒申鐃緒申鐃�1 byte鐃塾テワ申鐃緒申鐃夙わ申鐃緒申鐃緒申鐃緒申任鐃緒申襦ｏ申團鐃緒申鐃緒申鐃緒申鐃淑駕申鐃塾バワ申鐃夙随申鐃緒申任鐃春のテワ申鐃緒申鐃夙わ申鐃緒申鐃緒申鐃緒申襦ｏ申謄鐃緒申鐃緒申箸鐃緒申鐃緒申鐃緒申鐃緒申鐃緒申分鐃熟駕申鐃祝醐申鐃塾随申鐃緒申#000000鐃緒申鐃夙わ申鐃銃わ申癲�#070307鐃祝わ申鐃緒申鐃淑らず鐃緒申鐃緒申鐃銃わ申鐃縮わ申佑鐃緒申椶任呂曚箸鐃宿駈申鐃縮わ申鐃縦わ申鐃淑わ申鐃緒申



Demo 1








Get Image from URL:







Size:


0x0=0bytes



Text: 0





and









$('#demo0 input').click(function(){
    $('#demo0dst').text(showTextInPNG($('#demo0img').get(0)));
});

$('#demo1get').click(function(){
  $.get('http://api.dan.co.jp/datauri/' + $('#demo1url').val(), function(txt){
    $('#demo1img').attr('src', txt)
  })
});

$('#demo1img').load(function(){
  $('#demo1w').text(this.width);
  $('#demo1h').text(this.height);
  $('#demo1s').text(this.height*this.width);
});

$('#demo1txt').keyup(function(){
  var text = this.value,
      chars = text.length,
      bytes = Base64.utob(text).length;
  $('#demo1st').text([chars, 'chars,', bytes, 'bytes'].join(' '));
}).trigger('keyup');

$('#demo1embed').click(function(){
  $('#demo1timg').attr('src', 
    hideTextInPNG($('#demo1img').get(0), $('#demo1txt').val())
  );
});

$('#demo1extract').click(function(){
  $('#demo1dst').text(showTextInPNG($('#demo1timg').get(0)));
});



JavaScript鐃祝わ申鐃緒申鐃緒申




/*
 * You need base64.js.
 * cf: http://blog.livedoor.jp/dankogai/archives/51067688.html
*/

showTextInPNG = function(node) {
    var el  = document.createElement("canvas"),
        ctx = el.getContext("2d"),
        w   = el.width  = el.style.width  = node.width,
        h   = el.height = el.style.height = node.height;
    ctx.drawImage(node, 0, 0);
    var d = ctx.getImageData(0, 0, w, h).data,
        a = [];
    for(var i = 0, l = d.length; i < l; i += 4) {
        var c = ((d[i]   & 0x7) << 5)
              + ((d[i+1] & 0x3) << 3)
              +  (d[i+2] & 0x7);
        if (!c) break;
        a.push(String.fromCharCode(c));
    }
    return Base64.btou(a.join(''));
};

hideTextInPNG = function(node, txt) {
    var el  = document.createElement("canvas"),
        ctx = el.getContext("2d"),
        w   = el.width  = el.style.width  = node.width,
        h   = el.height = el.style.height = node.height,
        bin = Base64.utob(txt);
    ctx.drawImage(node, 0, 0);
    var imd = ctx.getImageData(0, 0, w, h),
        d = imd.data,
        a = [];
    for(var i = 0, l = d.length; i < l; i += 4) {
        var ord = bin.charCodeAt(i >> 2);
        d[i]   = (d[i]   & 0xf8) + ((ord & 0xf8) >> 5);
        d[i+1] = (d[i+1] & 0xfc) + ((ord & 0x18) >> 3);
        d[i+2] = (d[i+2] & 0xf8) +  (ord & 0x07);
    }
    ctx.putImageData(imd, 0, 0);
    return el.toDataURL('image/png');
};




See Also:



Dan the Steganographer