The example in this article describes the thumbnail generation class implemented by PHP that supports imagemagick and gd library processing, and its usage examples, which is of great practical value. Share it with everyone for your reference. The details are as follows:
1. Function:
1. Reduce/enlarge proportionally
2. Fill the background color
3. Crop by area
4. Add watermark, including watermark location, transparency, etc.
Using imagemagick/GD library to implement, imagemagick address: www.imagemagick.org
Imagemagick needs to be installed. The installation method is as follows: http://www.bkjia.com/article/55528.htm
2. Implementation method:
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; // 水印圖片透明度,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
?>
Demo sample code 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';
// 按比例生成缩略图
$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';
}
// 按比例生成缩略图,不足部分用#FF0000填充
$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';
}
// 裁剪250x250的缩略图,裁剪位置是底部中间,水印位置西南,透明度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';
}
// 按比例生成缩略图 CMYK格式
$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';
}
// 按比例生成缩略图,不足部分用#FF0000填充 CMYK格式
$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';
}
// 裁剪250x250的缩略图,裁剪位置是底部中间,水印位置西南,透明度50 CMYK格式
$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 will be helpful to everyone’s PHP programming
Try this class phpthumb
Configure phpthumb to use ImageMagick to generate thumbnails
phpthumb is a very powerful thumbnail generation class that supports image generation in jpg, bmp, gif, png and other formats. Whether you have a PHP project or other projects, as long as you have a PHP host, you can use phpthumb to bring you programming convenience. Because it also supports remote image generation.
phpthumb can be used with ImageMagick, so that it will no longer be limited by PHP memory size, and can also generate gif animations. Let's talk about how to let phpthumb use ImageMagick to generate images.
Whether it is a win platform or a linux platform, phpthumb turns on ImageMagick by default, but there are some minor configuration errors and program problems. The first step is to install the ImageMagick program. There is no need to install the php_imagick PHP extension. phpthumb uses the command line, so php should be able to run a process, otherwise please choose another host. After installation, please follow the steps below to modify phpthumb.
1. Open phpThumb.config.php and find
if (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN') {
// Windows: set absolute pathname
$PHPTHUMB_CONFIG ['imagemagick_path'] = 'C:/Program Files/ImageMagick-6.6.0-Q16/convert.exe';
} else {
// *nix: set absolute pathname to "convert", or leave as null if "convert" is in the path (location detected with `which`)
//$PHPTHUMB_CONFIG['imagemagick_path'] = '/usr/local/bin/convert';
$PHPTHUMB_CONFIG['imagemagick_path '] = null;
}
Set $PHPTHUMB_CONFIG['imagemagick_path'] above to the correct path for your installation. There are two places in total, the first is the window platform. The second one is for LINUX and UNIX platforms. Please select settings based on your system. The red part above is the ImageMagick path. When replacing, please note that the directory separator is / and not \.
2. Open phpThumb.class.php
and look for function ImageMagickVersion($returnRAW=false) {near here
there is if (eregi('^Version: [^0-9]*([ 0- 9\\.\\:Q/]+) (http|file)\:', $versionstring[1], $matches)) {
replace with if (eregi('^Version: (.+) ( http|file)\:', $versionstring[1], $matches)) {
OK All settings have been completed. Your phpthumb has automatically used ImageMagick to generate images...the rest of the full text>>
I have never used ImageMagick. I usually use the built-in GD library directly, and I have not found the serious distortion problem you mentioned.
The general idea of using the GD library to create thumbnails is as follows:
Create a true color canvas according to the set size $im=createtruecolor(120,90);
Read the original file size and use the width of the original size and height ratio, calculate the size of the thumbnail (which may deviate from the given dimensions)
Copy and scale the original image to the created true color thumbnail canvas.
Output thumbnail file.
Maybe it’s because it uses true color and the thumbnail effect is just okay, but it doesn’t mean it’s absolutely distortion-free.
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