I'm learning <em>png</em> <em>IDAT</em> chunks now. I tried writing my own code to read them, and it works fine if there is only 1 <em>IDAT</em> chunk, but fails when there are more "<em>IDAT</em> 78 DA" chunks. My question is that: What should I modify in my code and how?
Thanks for all the replies. :)
<?php
$in_filename = "stego15.<em>png</em>";
$raw_data = file_get_contents($in_filename);
$idat_chunks = explode('<em>IDAT</em>', substr($raw_data, 0, -4));
foreach ($idat_chunks as $idat_number=>$idat_chunk) {
if ($idat_number==0) {
continue;
}
$chunk = substr($idat_chunk, 2, -4);
$decompressed = gzinflate($chunk);
list($width, $height) = getimagesize($in_filename);
$data = str_split(bin2hex($decompressed), $width*6+2);
$grouped_data = array();
foreach ($data as $row=>$d) {
$grouped_data[$row] = str_split(substr($d, 2), 6);
}
echo '<h1>'.$idat_number.'. chunk</h1>';
var_dump($grouped_data);
}
?>
这几天逛CSDN论坛，发现在一些前端模块发的问题大都是因为var、let和const搞不清楚导致的，今天我来浅析下，希望对看到这篇博客的童鞋有所帮助~
What we know is that…（英语作文万能开头） :在JavaScript<em>中</em>有三种声明变量的方式：var、let、const。
目录1.var2. let3. const
1.var
（1）var定义的变量在之后可以修改，如果不初始...
Feature matching is at the base of many computer vision problems, such as object recognition or structure from motion. Current methods rely on costly descriptors for detection and matching. In this paper, we propose a very fast binary descriptor based on BRIEF, called ORB,
相关下载链接：[url=//download.csdn.net/download/aven79/6459901?utm_source=bbsseo]//download.csdn.net/download/aven79/6459901?utm_source=bbsseo[/url]
