A thumbnail generation class implemented by php that supports imagemagick and gd libraries
- 2021-07-21 07:52:57
- OfStack
This paper describes the thumbnail generation class implemented by php, which supports imagemagick and gd libraries, and its usage examples, which are of great practical value. Share it for your reference. The details are as follows:
1. Functions:
1. Scale out/zoom in
Step 2 Fill the background color
3. Cut by region
4. Add the watermark, including the location and transparency of the watermark
It is implemented using imagemagick/GD library, imagemagick address: www. imagemagick. org
imagemagick needs to be installed as follows: https://www.ofstack.com/article/55528. htm
2. Implementation method:
The PicThumb. class. php class file is as follows:
<?php
/** 缩略图生成类,支持imagemagick及gd库两种处理
* Date: 2013-07-15
* Author: fdipzone
* Ver: 1.2
*
* Func:
* public set_config: 设置参数
* public create_thumb: 生成缩略图
* private fit: 缩略图片
* private crop: 裁剪图片
* private gd_fit: GD库缩略图片
* private gd_crop: GD库裁剪图片
* private get_size: 获取要转换的size
* private get_crop_offset: 获取裁图的偏移量
* private add_watermark: 添加水印
* private check_handler: 判断处理程序是否已安装
* private create_dirs: 创建目录
* private exists: 判断参数是否存在
* private to_log: 记录log
* private hex2rgb: hex颜色转rgb颜色
* private get_file_ext: 获取图片类型
*
* ver: 1.1 增加GD库处理
* ver: 1.2 增加width,height错误参数处理
* 增加当图片colorspace不为RGB时作转RGB处理
* 修正使用crop保存为gif时出现透明无效区域问题，使用+repage参数，删除透明无效区域即可
*
* tips:建议使用imagemagick
* GD库不支持透明度水印,如果必须使用透明水印,请将水印图片做成有透明度。
* GD库输出gif如加透明水印，会有问题。
*/
class PicThumb{ // class start
private $_log = null; // log file
private $_handler = null; // 进行图片处理的程序,imagemagick/gd库
private $_type = 'fit'; // fit or crop
private $_source = null; // 原图路径
private $_dest = null; // 缩略图路径
private $_watermark = null; // 水印图片
private $_opacity = 75; // 水印�片透明度,gd库不支持
private $_gravity = 'SouthEast'; // 水印摆放位置 NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast
private $_geometry = '+10+10'; // 水印定位,gd库不支持
private $_croppos = 'TL'; // 截图的位置 TL TM TR ML MM MR BL BM BR
private $_bgcolor = null; // 填充的背景色
private $_quality = 90; // 生成的图片质量
private $_width = null; // 指定区域宽度
private $_height = null; // 指定区域高度
// 初始化
public function __construct($logfile=''){
if($logfile!=''){
$this->_log = $logfile;
}
}
// 设置参数
public function set_config($param=array()){
$this->_handler = $this->exists($param, 'handler')? strtolower($param['handler']) : null;
$this->_type = $this->exists($param, 'type')? strtolower($param['type']) : 'fit';
$this->_watermark = $this->exists($param, 'watermark')? $param['watermark'] : null;
$this->_opacity = $this->exists($param, 'opacity')? $param['opacity'] : 75;
$this->_gravity = $this->exists($param, 'gravity')? $param['gravity'] : 'SouthEast';
$this->_geometry = $this->exists($param, 'geometry')? $param['geometry'] : '+10+10';
$this->_croppos = $this->exists($param, 'croppos')? $param['croppos'] : 'TL';
$this->_bgcolor = $this->exists($param, 'bgcolor')? $param['bgcolor'] : null;
$this->_quality = $this->exists($param, 'quality')? $param['quality'] : 90;
$this->_width = $this->exists($param, 'width')? $param['width'] : null;
$this->_height = $this->exists($param, 'height')? $param['height'] : null;
}
/** 创建缩略图
* @param String $source 原图
* @param String $dest 目标图
* @return boolean
*/
public function create_thumb($source, $dest){
// 检查使用的handler是否已安装
if(!$this->check_handler()){
$this->to_log('handler not installed');
return false;
}
// 判断区域宽高是否正确
if(!is_numeric($this->_width) || !is_numeric($this->_height) || $this->_width<=0 || $this->_height<=0){
$this->to_log('width or height invalid');
return false;
}
// 判断源文件是否存在
if(!file_exists($source)){
$this->to_log($source.' not exists');
return false;
}
// 创建目标文件路径
if(!$this->create_dirs($dest)){
$this->to_log(dirname($dest).' create fail');
return false;
}
$this->_source = $source; // 源文件
$this->_dest = $dest; // 目标文件
// 处理图片
switch($this->_type){
case 'fit':
if($this->_handler=='imagemagick'){
return $this->fit();
}else{
return $this->gd_fit();
}
break;
case 'crop':
if($this->_handler=='imagemagick'){
return $this->crop();
}else{
return $this->gd_crop();
}
break;
default:
$this->to_log($this->_type.' not fit and crop');
return false;
}
}
/** 按比例压缩或拉伸图片
* @return boolean
*/
private function fit(){
// 判断是否填充背景
$bgcolor = ($this->_bgcolor!=null)?
sprintf(" -background '%s' -gravity center -extent '%sx%s' ", $this->_bgcolor, $this->_width, $this->_height) : "";
// 判断是否要转为RGB
$source_info = getimagesize($this->_source);
$colorspace = (!isset($source_info['channels']) || $source_info['channels']!=3)? ' -colorspace RGB ' : '';
// 命令行
$cmd = sprintf("convert -resize '%sx%s' '%s' %s -quality %s %s '%s'", $this->_width, $this->_height, $this->_source, $bgcolor, $this->_quality, $colorspace, $this->_dest);
// 记录执行的命令
$this->to_log($cmd);
// 执行命令
exec($cmd);
// 添加水印
$this->add_watermark($this->_dest);
return is_file($this->_dest)? true : false;
}
/** 裁剪图片
* @return boolean
*/
private function crop(){
// 获取生成的图片尺寸
list($pic_w, $pic_h) = $this->get_size();
// 获取截图的偏移量
list($offset_w, $offset_h) = $this->get_crop_offset($pic_w, $pic_h);
// 判断是否要转为RGB
$source_info = getimagesize($this->_source);
$colorspace = (!isset($source_info['channels']) || $source_info['channels']!=3)? ' -colorspace RGB ' : '';
// 命令行
$cmd = sprintf("convert -resize '%sx%s' '%s' -quality %s %s -crop %sx%s+%s+%s +repage '%s'", $pic_w, $pic_h, $this->_source, $this->_quality, $colorspace, $this->_width, $this->_height, $offset_w, $offset_h, $this->_dest);
// 记录执行的命令
$this->to_log($cmd);
// 执行命令
exec($cmd);
// 添加水印
$this->add_watermark($this->_dest);
return is_file($this->_dest)? true : false;
}
/** GD库按比例压缩或拉伸图片
* @return boolean
*/
private function gd_fit(){
// 获取生成的图片尺寸
list($pic_w, $pic_h) = $this->get_size();
list($owidth, $oheight, $otype) = getimagesize($this->_source);
switch($otype){
case 1: $source_img = imagecreatefromgif($this->_source); break;
case 2: $source_img = imagecreatefromjpeg($this->_source); break;
case 3: $source_img = imagecreatefrompng($this->_source); break;
default: return false;
}
// 按比例缩略/拉伸图片
$new_img = imagecreatetruecolor($pic_w, $pic_h);
imagecopyresampled($new_img, $source_img, 0, 0, 0, 0, $pic_w, $pic_h, $owidth, $oheight);
// 判断是否填充背景
if($this->_bgcolor!=null){
$bg_img = imagecreatetruecolor($this->_width, $this->_height);
$rgb = $this->hex2rgb($this->_bgcolor);
$bgcolor =imagecolorallocate($bg_img, $rgb['r'], $rgb['g'], $rgb['b']);
imagefill($bg_img, 0, 0, $bgcolor);
imagecopy($bg_img, $new_img, (int)(($this->_width-$pic_w)/2), (int)(($this->_height-$pic_h)/2), 0, 0, $pic_w, $pic_h);
$new_img = $bg_img;
}
// 获取目标图片的类型
$dest_ext = $this->get_file_ext($this->_dest);
// 生成图片
switch($dest_ext){
case 1: imagegif($new_img, $this->_dest, $this->_quality); break;
case 2: imagejpeg($new_img, $this->_dest, $this->_quality); break;
case 3: imagepng($new_img, $this->_dest, (int)(($this->_quality-1)/10)); break;
}
if(isset($source_img)){
imagedestroy($source_img);
}
if(isset($new_img)){
imagedestroy($new_img);
}
// 添加水印
$this->add_watermark($this->_dest);
return is_file($this->_dest)? true : false;
}
/** GD库裁剪图片
* @return boolean
*/
private function gd_crop(){
// 获取生成的图片尺寸
list($pic_w, $pic_h) = $this->get_size();
// 获取截图的偏移量
list($offset_w, $offset_h) = $this->get_crop_offset($pic_w, $pic_h);
list($owidth, $oheight, $otype) = getimagesize($this->_source);
switch($otype){
case 1: $source_img = imagecreatefromgif($this->_source); break;
case 2: $source_img = imagecreatefromjpeg($this->_source); break;
case 3: $source_img = imagecreatefrompng($this->_source); break;
default: return false;
}
// 按比例缩略/拉伸图片
$tmp_img = imagecreatetruecolor($pic_w, $pic_h);
imagecopyresampled($tmp_img, $source_img, 0, 0, 0, 0, $pic_w, $pic_h, $owidth, $oheight);
// 裁剪图片
$new_img = imagecreatetruecolor($this->_width, $this->_height);
imagecopyresampled($new_img, $tmp_img, 0, 0, $offset_w, $offset_h, $this->_width, $this->_height, $this->_width, $this->_height);
// 获取目标图片的类型
$dest_ext = $this->get_file_ext($this->_dest);
// 生成图片
switch($dest_ext){
case 1: imagegif($new_img, $this->_dest, $this->_quality); break;
case 2: imagejpeg($new_img, $this->_dest, $this->_quality); break;
case 3: imagepng($new_img, $this->_dest, (int)(($this->_quality-1)/10)); break;
}
if(isset($source_img)){
imagedestroy($source_img);
}
if(isset($tmp_img)){
imagedestroy($tmp_img);
}
if(isset($new_img)){
imagedestroy($new_img);
}
// 添加水印
$this->add_watermark($this->_dest);
return is_file($this->_dest)? true : false;
}
/** 获取目标图生成的size
* @return Array $width, $height
*/
private function get_size(){
list($owidth, $oheight) = getimagesize($this->_source);
$width = (int)($this->_width);
$height = (int)($this->_height);
switch($this->_type){
case 'fit':
$pic_w = $width;
$pic_h = (int)($pic_w*$oheight/$owidth);
if($pic_h>$height){
$pic_h = $height;
$pic_w = (int)($pic_h*$owidth/$oheight);
}
break;
case 'crop':
if($owidth>$oheight){
$pic_h = $height;
$pic_w = (int)($pic_h*$owidth/$oheight);
}else{
$pic_w = $width;
$pic_h = (int)($pic_w*$oheight/$owidth);
}
break;
}
return array($pic_w, $pic_h);
}
/** 获取截图的偏移量
* @param int $pic_w 图宽度
* @param int $pic_h 图高度
* @return Array $offset_w, $offset_h
*/
private function get_crop_offset($pic_w, $pic_h){
$offset_w = 0;
$offset_h = 0;
switch(strtoupper($this->_croppos)){
case 'TL':
$offset_w = 0;
$offset_h = 0;
break;
case 'TM':
$offset_w = (int)(($pic_w-$this->_width)/2);
$offset_h = 0;
break;
case 'TR':
$offset_w = (int)($pic_w-$this->_width);
$offset_h = 0;
break;
case 'ML':
$offset_w = 0;
$offset_h = (int)(($pic_h-$this->_height)/2);
break;
case 'MM':
$offset_w = (int)(($pic_w-$this->_width)/2);
$offset_h = (int)(($pic_h-$this->_height)/2);
break;
case 'MR':
$offset_w = (int)($pic_w-$this->_width);
$offset_h = (int)(($pic_h-$this->_height)/2);
break;
case 'BL':
$offset_w = 0;
$offset_h = (int)($pic_h-$this->_height);
break;
case 'BM':
$offset_w = (int)(($pic_w-$this->_width)/2);
$offset_h = (int)($pic_h-$this->_height);
break;
case 'BR':
$offset_w = (int)($pic_w-$this->_width);
$offset_h = (int)($pic_h-$this->_height);
break;
}
return array($offset_w, $offset_h);
}
/** 添加水印
* @param String $dest 图片路径
*/
private function add_watermark($dest){
if($this->_watermark!=null && file_exists($this->_watermark) && file_exists($dest)){
list($owidth, $oheight, $otype) = getimagesize($dest);
list($w, $h, $wtype) = getimagesize($this->_watermark);
// 水印图比原图要小才加水印
if($w<=$owidth && $h<=$oheight){
if($this->_handler=='imagemagick'){ // imagemagick 添加水印
$cmd = sprintf("composite -gravity %s -geometry %s -dissolve %s '%s' %s %s", $this->_gravity, $this->_geometry, $this->_opacity, $this->_watermark, $dest, $dest);
$this->to_log($cmd);
exec($cmd);
}else{ // gd 添加水印
switch($wtype){
case 1: $water_img = imagecreatefromgif($this->_watermark); break;
case 2: $water_img = imagecreatefromjpeg($this->_watermark); break;
case 3: $water_img = imagecreatefrompng($this->_watermark); break;
default: return false;
}
switch($otype){
case 1: $dest_img = imagecreatefromgif($dest); break;
case 2: $dest_img = imagecreatefromjpeg($dest); break;
case 3: $dest_img = imagecreatefrompng($dest); break;
default: return false;
}
// 水印位置
switch(strtolower($this->_gravity)){
case 'northwest':
$posX = 0;
$posY = 0;
break;
case 'north':
$posX = ($owidth - $w) / 2;
$posY = 0;
break;
case 'northeast':
$posX = $owidth - $w;
$posY = 0;
break;
case 'west':
$posX = 0;
$posY = ($oheight - $h) / 2;
break;
case 'center':
$posX = ($owidth - $w) / 2;
$posY = ($oheight - $h) / 2;
break;
case 'east':
$posX = $owidth - $w;
$posY = ($oheight - $h) / 2;
break;
case 'southwest':
$posX = 0;
$posY = $oheight - $h;
break;
case 'south':
$posX = ($owidth - $w) / 2;
$posY = $oheight - $h;
break;
case 'southeast':
$posX = $owidth - $w;
$posY = $oheight - $h;
break;
}
imagealphablending($dest_img, true);
imagecopy($dest_img, $water_img, $posX, $posY, 0, 0, $w, $h);
switch($otype){
case 1:imagegif($dest_img, $dest, $this->_quality); break;
case 2:imagejpeg($dest_img, $dest, $this->_quality); break;
case 3:imagepng($dest_img, $dest, (int)(($this->_quality-1)/10)); break;
}
if(isset($water_img)){
imagedestroy($water_img);
}
if(isset($dest_img)){
imagedestroy($dest_img);
}
}
}
}
}
/** 判断处理程序是否已安装
* @return boolean
*/
private function check_handler(){
$handler = $this->_handler;
if(!in_array($handler, array('imagemagick', 'gd', null))){
return false;
}
// 检查是否有安装imagemagick
$imagemagick_installed = strstr(shell_exec('convert -version'),'Version: ImageMagick')!=''? true : false;
// 检查是否有安装gd库
$gd_installed = function_exists('gd_info')? true : false;
switch($handler){
case 'imagemagick':
return $imagemagick_installed;
break;
case 'gd':
return $gd_installed;
break;
case null:
if($imagemagick_installed){
$this->_handler = 'imagemagick';
return true;
}
if($gd_installed){
$this->_handler = 'gd';
return true;
}
break;
}
return false;
}
/** 创建图片目录
* @param String $path
* @return boolean
*/
private function create_dirs($dest){
if(!is_dir(dirname($dest))){
return mkdir(dirname($dest), 0777, true);
}
return true;
}
/** 判断参数是否存在
* @param Array $obj 数组对象
* @param String $key 要查找的key
* @return boolean
*/
private function exists($obj,$key=''){
if($key==''){
return isset($obj) && !empty($obj);
}else{
$keys = explode('.',$key);
for($i=0,$max=count($keys); $i<$max; $i++){
if(isset($obj[$keys[$i]])){
$obj = $obj[$keys[$i]];
}else{
return false;
}
}
return isset($obj) && !empty($obj);
}
}
/** 记录log
* @param String $msg 要记录的log讯息
*/
private function to_log($msg){
if($this->_log){
$msg = '['.date('Y-m-d H:i:s').']'.$msg."\r\n";
file_put_contents($this->_log, $msg, FILE_APPEND);
}
}
/** hex颜色转rgb颜色
* @param String $color hex颜色
* @return Array
*/
private function hex2rgb($hexcolor){
$color = str_replace('#', '', $hexcolor);
if (strlen($color) > 3) {
$rgb = array(
'r' => hexdec(substr($color, 0, 2)),
'g' => hexdec(substr($color, 2, 2)),
'b' => hexdec(substr($color, 4, 2))
);
} else {
$r = substr($color, 0, 1) . substr($color, 0, 1);
$g = substr($color, 1, 1) . substr($color, 1, 1);
$b = substr($color, 2, 1) . substr($color, 2, 1);
$rgb = array(
'r' => hexdec($r),
'g' => hexdec($g),
'b' => hexdec($b)
);
}
return $rgb;
}
/** 获取图片类型
* @param String $file 图片路径
* @return int
*/
private function get_file_ext($file){
$filename = basename($file);
list($name, $ext)= explode('.', $filename);
$ext_type = 0;
switch(strtolower($ext)){
case 'jpg':
case 'jpeg':
$ext_type = 2;
break;
case 'gif':
$ext_type = 1;
break;
case 'png':
$ext_type = 3;
break;
}
return $ext_type;
}
} // class end
?>
The sample code for demo is as follows:
<?php
define('ROOT', dirname(__FILE__));
require(ROOT."/PicThumb.class.php");
$logfile = ROOT.'/PicThumb.log';
$source1 = ROOT.'/pic/source.jpg';
$dest1 = ROOT.'/pic/1.jpg';
$dest2 = ROOT.'/pic/2.gif';
$dest3 = ROOT.'/pic/3.png';
$source2 = ROOT.'/pic/source_cmyk.jpg';
$dest4 = ROOT.'/pic/4.jpg';
$dest5 = ROOT.'/pic/5.gif';
$dest6 = ROOT.'/pic/6.png';
$watermark = ROOT.'/pic/watermark.png';
// Generate thumbnails to scale
$param = array(
'type' => 'fit',
'width' => 100,
'height' => 100,
);
$obj = new PicThumb($logfile);
$obj->set_config($param);
$flag = $obj->create_thumb($source1, $dest1);
if($flag){
echo '<img src="pic/'.basename($dest1).'">';
}else{
echo 'create thumb fail';
}
// Generate thumbnails to scale , Use the insufficient part #FF0000 Padding
$param = array(
'type' => 'fit',
'width' => 100,
'height' => 100,
'bgcolor' => '#FFFF00'
);
$obj = new PicThumb($logfile);
$obj->set_config($param);
$flag = $obj->create_thumb($source1, $dest2);
if($flag){
echo '<img src="pic/'.basename($dest2).'">';
}else{
echo 'create thumb fail';
}
// Cutting 250x250 Thumbnails of , The clipping position is the middle of the bottom , Watermark location southwest , Transparency 50
$param = array(
'type' => 'crop',
'croppos' => 'BM',
'width' => 250,
'height' => 250,
'watermark' => $watermark,
'opacity' => 50,
'gravity' => 'SouthWest'
);
$obj = new PicThumb($logfile);
$obj->set_config($param);
$flag = $obj->create_thumb($source1, $dest3);
if($flag){
echo '<img src="pic/'.basename($dest3).'">';
}else{
echo 'create thumb fail';
}
// Generate thumbnails to scale CMYK Format
$param = array(
'type' => 'fit',
'width' => 100,
'height' => 100,
);
$obj = new PicThumb($logfile);
$obj->set_config($param);
$flag = $obj->create_thumb($source2, $dest4);
if($flag){
echo '<img src="pic/'.basename($dest4).'">';
}else{
echo 'create thumb fail';
}
// Generate thumbnails to scale , Use the insufficient part #FF0000 Padding CMYK Format
$param = array(
'type' => 'fit',
'width' => 100,
'height' => 100,
'bgcolor' => '#FFFF00'
);
$obj = new PicThumb($logfile);
$obj->set_config($param);
$flag = $obj->create_thumb($source2, $dest5);
if($flag){
echo '<img src="pic/'.basename($dest5).'">';
}else{
echo 'create thumb fail';
}
// Cutting 250x250 Thumbnails of , The clipping position is the middle of the bottom , Watermark location southwest , Transparency 50 CMYK Format
$param = array(
'type' => 'crop',
'croppos' => 'BM',
'width' => 250,
'height' => 250,
'watermark' => $watermark,
'opacity' => 50,
'gravity' => 'SouthWest'
);
$obj = new PicThumb($logfile);
$obj->set_config($param);
$flag = $obj->create_thumb($source2, $dest6);
if($flag){
echo '<img src="pic/'.basename($dest6).'">';
}else{
echo 'create thumb fail';
}
?>
Click here to download the complete example code of this article.
I hope this article is helpful to everyone's PHP programming