PHP Hacks

Chapter 4. Graphics

Hacks 27–33: Introduction

It’s easy to think of PHP as nothing more than a scripting language for HTML. But PHP is far more than that, with support for databases, graphing, image manipulation, and a lot more. This chapter details hacks for building beautiful graphics with bitmaps, vector graphics, and even Dynamic HTML (DHTML). You’ll even see how you can take photos from your iPhoto library and export them into HTML—all with that “HTML scripting language,” PHP.

Create Thumbnail Images

Use the GD graphics API in PHP to create thumbnails of your images.

This simple hack takes a set of JPEG images in a directory named pics and creates thumbnails of them in a directory named thumbs. It also creates a file in the same directory as the script called index.html, which contains all of the thumbnails, as well as links to the original images.

The Code

Save the code in Example 4-1 as mkthumbs.php.

Example 4-1. A script for handling thumbnail creation

 <?php $dir = opendir( "pics" ); $pics = array(); while( $fname = readdir( $dir ) ) { if ( preg_match( "/[.]jpg$/", $fname ) ) $pics []= $fname; } closedir( $dir ); foreach( $pics as $fname ) { $im = imagecreatefromjpeg( "pics/$fname" ); $ox = imagesx( $im ); $oy = imagesy( $im ); $nx = 100; $ny = floor( $oy * ( 100 / $ox ) ); $nm = imagecreatetruecolor( $nx, $ny ); imagecopyresampled( $nm, $im, 0, 0, 0, 0, $nx, $ny, $ox, $oy ); print "Creating thumb for $fname\n"; imagejpeg( $nm, "thumbs/$fname" ); } print "Creating index.html\n"; ...