'PHP programming the fastest to understand' lecture 7: PHP image verification code and thumbnails

Example 22 image validation core code

 
<?php 
//header("content-type:image/png"); 
$num ='1234'; 
$imagewidth=60; 
$imageheight=18; 

$numimage = imagecreate($imagewidth,$imageheight); 
imagecolorallocate($numimage,240,240,240); 
for($i=0;$i<strlen($num);$i++){ 
$x = mt_rand(1,8)+$imagewidth*$i/4; 
$y = mt_rand(1,$imageheight/4); 
$color=imagecolorallocate($numimage,mt_rand(0,150),mt_rand(0,150),mt_rand(0,150)); 
imagestring($numimage,5,$x,$y,$num[$i],$color); 
} 

for($i=0;$i<200;$i++){ 
$randcolor=imagecolorallocate($numimage,rand(200,255),rand(200,255),rand(200,255)); 
imagesetpixel($numimage,rand()%70,rand()%20,$randcolor); 
} 
imagepng($numimage); 
imagedestroy($numimage); 
?> 

This is an example of four captcha output, for Chinese characters, need the font file and imagettftext function, when you use the Internet search it. You're going to generate random Numbers, and there's the mt_rand function; You're also going to use session to hold this random number; If you want to convert to utf-8, you need the iconv function.

Example 23 thumbnail

 
<?php 
class SimpleImage { 
var $image; 
var $image_type; 
function load($filename) { 
$image_info = getimagesize($filename); 
$this->image_type = $image_info[2]; 
if( $this->image_type == IMAGETYPE_JPEG ) { 
$this->image = imagecreatefromjpeg($filename); 
} elseif( $this->image_type == IMAGETYPE_GIF ) { 
$this->image = imagecreatefromgif($filename); 
} elseif( $this->image_type == IMAGETYPE_PNG ) { 
$this->image = imagecreatefrompng($filename); 
} 
} 
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) { 
if( $image_type == IMAGETYPE_JPEG ) { 
imagejpeg($this->image,$filename,$compression); 
} elseif( $image_type == IMAGETYPE_GIF ) { 
imagegif($this->image,$filename); 
} elseif( $image_type == IMAGETYPE_PNG ) { 
imagepng($this->image,$filename); 
} 
if( $permissions != null) { 
chmod($filename,$permissions); 
} 
} 
function output($image_type=IMAGETYPE_JPEG) { 
if( $image_type == IMAGETYPE_JPEG ) { 
imagejpeg($this->image); 
} elseif( $image_type == IMAGETYPE_GIF ) { 
imagegif($this->image); 
} elseif( $image_type == IMAGETYPE_PNG ) { 
imagepng($this->image); 
} 
} 
function getWidth() { 
return imagesx($this->image); 
} 
function getHeight() { 
return imagesy($this->image); 
} 
function resizeToHeight($height) { 
$ratio = $height / $this->getHeight(); 
$width = $this->getWidth() * $ratio; 
$this->resize($width,$height); 
} 
function resizeToWidth($width) { 
$ratio = $width / $this->getWidth(); 
$height = $this->getheight() * $ratio; 
$this->resize($width,$height); 
} 
function scale($scale) { 
$width = $this->getWidth() * $scale/100; 
$height = $this->getheight() * $scale/100; 
$this->resize($width,$height); 
} 
function resize($width,$height) { 
$new_image = imagecreatetruecolor($width, $height); 
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight()); 
$this->image = $new_image; 
} 
} 

$newfile = UPLOAD_DIR."/icons/".md5($_SESSION['USER']->email).".jpg";//Upload files to save directory
$image = new SimpleImage(); 
$image->load($_FILES['icons']['tmp_name']);//Temporary file name for upload
$image->resizeToWidth(80); Set the width  
$image->save($newfile); 
?>