PHP class implementation code for processing images_PHP tutorial

/**
* author:yagas
* email:yagas60@21cn.com
*/
class Image
{
/**Class protected variables*/
protected $th_width = 100;
protected $th_height = 50;
protected $quality = 85; //Picture quality
protected $transparent = 50; //Watermark transparency
protected $background = "255,255,255"; //Background color
/**
* Generate thumbnail file
* @param $src original image file
* @param $dst target file
*/
public function thumb($src, $dst=null, $output=true)
{
$thumb = array($this->th_width, $this->th_height);
$this->scale($src, $thumb, $dst, $output);
}
/**
* Scale the image by percentage
* @param string $src original image file
* @param string $dst input target file
* @param float/array $zoom scaling ratio, Bloom by percentage for floating point type, and scale by specified size for array type
* @param boolean $output Whether to generate file output
*/
public function scale($src, $dst=null, $zoom=1, $output=true)
{
if(!file_exists($src)) die('File not exists.');
if(!$zoom) die('the zoom undefine.');
$src_im = $this->IM($src);
$old_width = imagesx($src_im);
if( is_float($zoom)) {
//Zoom by percentage
$new_width = $old_width * $zoom;
}
elseif(is_array($zoom)) {
//Clear The zoom size
$new_width = $zoom[0];
}
//Whether the zoom height is defined
if(!isset($zoom[1])) {
/ /Scaling
$resize_im = $this->imageresize($src_im, $new_width);
}
else {
//Non-scaling
$resize_im = $this ->imageresize($src_im, $new_width, $zoom[1]);
}
if(!$output) {
header("Content-type: image/jpeg");
imagejpeg($resize_im, null, $this->quality);
}
else {
$new_file = empty($dst)? $src:$dst;
imagejpeg($resize_im , $new_file, $this->quality);
}
imagedestroy($im);
imagedestroy($nIm);
}
/**
* Crop the image
* @param $src original file
* @param $dst target file
* @param $output whether to generate the target file
*/
public function capture($src, $dst=null, $output=true) {
if(!file_exists($src)) die('File not exists.');
$width = $this ->th_width;
$height = $this->th_height;
$src_im = $this->IM($src);
$old_width = imagesx($src_im);
$old_height = imagesy($src_im);
$capture = imagecreatetruecolor($width, $height);
$rgb = explode(",", $this->background);
$white = imagecolorallocate($capture, $rgb[0], $rgb[1], $rgb[2]);
imagefill($capture, 0, 0, $white);
//When the image is larger than the thumbnail Zoom when
if($old_width > $width && $old_height>$height) {
$resize_im = $this->imageresize($src_im, $width);
//The image ratio is not appropriate When normalizing, recalculate the proportion for cropping
if(imagesy($resize_im) < $height) {
$proportion = $old_height/$this->th_height;
$resize_im = $this- >imageresize($src_im, $old_width/$proportion);
}
$posx = 0;
$posy = 0;
}
else {
//The image is smaller than Center the image when thumbnailing
$posx = ($width-$old_width)/2;
$posy = ($height-$old_height)/2;
$resize_im = $src_im;
}
imagecopy($capture, $resize_im, $posx, $posy, 0, 0, imagesx($resize_im), imagesy($resize_im));
if(!$output) {
header ("Content-type: image/jpeg");
imagejpeg($capture, null, $this->quality);
}
else {
$new_file = empty($dst) ? $src:$dst;
imagejpeg($capture, $new_file, $this->quality);
}
imagedestroy($src_im);
@imagedestroy($resize_im);
imagedestroy($capture);
}
/**
* Write watermark image
* @param $src The image that needs to be watermarked
* @param $mark Watermark image
* @param $transparent Watermark transparency
*/
public function mark($src, $mark, $dst='', $output=true)
{
$mark_info = getimagesize($mark);
$src_info = getimagesize($src);
list($mw,$mh) = $mark_info;
list($sw,$sh ) = $src_info;
$px = $sw - $mw;
$py = $sh - $mh;
$im = $this->IM($src);
$ mim = $this->IM($mark);
imagecopymerge($im, $mim, $px, $py, 0, 0, $mw, $mh, $this->transparent);
if($output){
$new_file = empty($dst)? $src:$dst;
imagejpeg($im, $new_file, $this->quality);
}
else
{
header('Content-type: image/jpeg');
imagejpeg($im);
}
imagedestroy($im);
imagedestroy($ mim);
}
/**
* Obtain different GD objects through files
*/
protected function IM($file)
{
if(!file_exists($file)) die('File not exists.');
$info = getimagesize($file);
switch($info['mime'])
{
case 'image/gif':
$mim = imagecreatefromgif($file);
break;
case 'image/png':
$mim = imagecreatefrompng($file);
imagealphablending($mim, false);
imagesavealpha($mim, true);
break;
case 'image/jpeg':
$mim = imagecreatefromjpeg($file);
break;
default:
die('File format errors.');
}
return $mim;
}
/**
* Processing of scaling the image
* @param resource $src_im image GD object
* @param integer $width width of the image
* @param integer $height height of the image, if not set Height, the image will be scaled proportionally
* @return resuorce $im returns a GD object
*/
protected function imageresize($src_im, $width, $height=null) {
$old_width = imagesx($src_im);
$old_height = imagesy($src_im);
$proportion = $old_width/$old_height;
$new_width = $width;
$new_height = is_null($height)? round($new_width / $proportion):$height;
//创建新的图象并填充默认的背景色
$im = imagecreatetruecolor($new_width, $new_height);
$rgb = explode(",", $this->background);
$white = imagecolorallocate($im, $rgb[0], $rgb[1], $rgb[2]);
imagefill($im, 0, 0, $white);
//对图片进行缩放
imagecopyresized($im, $src_im, 0, 0, 0, 0, $new_width, $new_height, $old_width, $old_height);
return $im;
}
/**
* Class variable assignment
*/
public function __set($key, $value)
{
$this->$key = $value;
}
/**
* Get class variable value
*/
public function __get($key)
{
return $this->$key;
}
}
?>