The method of generating thumbnail based on PHP server image is explained in detail

<?php
// Define a thumbnail image size 
$picSize = array(
              '100_100'=> 1,
              '200_100'=> 1
           );
$imagePath = "../image/";
function parseUrl($url){
   preg_match("/(?P<name>[\w\d]+)_w(?P<width>\d+)_h(?P<height>\d+)\.(?P<ext>\w+)/",$url,$match);
   return $match;
}
$urlArr = explode("/",$_SERVER['REQUEST_URI']);
$imgName = $urlArr[count($urlArr)-1];
$picInfo = parseUrl($imgName);
// The wrong size 
if(empty($picInfo['width']) || empty($picInfo['height']) ||
!array_key_exists($picInfo['width'].'_'.$picInfo['height'],$picSize)) die(' This size image does not exist ');
$originalPic = $imagePath.$picInfo['name'].'/'.$picInfo['name'].'.'.$picInfo['ext'];
// The original diagram does not exist 
if(!file_exists($originalPic)) die(" The picture does not exist! ");
/**
 * Equal scale compression of images 
 */
switch($picInfo['ext']){
   case 'jpg':
      $orgImg = ImageCreateFromJpeg($originalPic);
      break;
   default: 
      break;
}
$owidth  =  ImageSX($orgImg); // The original size 
$oheight =  ImageSY($orgImg);
$tW = $picInfo['width'];
$tH = $picInfo['height'];
// Gets the thumbnail size 
if($owidth/$oheight > $tW/$tH){
    $tH = intval($tW * $oheight/$owidth);
}else{
     $tW = intval($tH * $owidth/$oheight);
}
// Generate background map 
$new_img = ImageCreateTrueColor($picInfo['width'], $picInfo['height']);
$bgColor = imagecolorallocate($new_img,255,255,255);
if (!@imagefilledrectangle($new_img, 0, 0, $picInfo['width']-1, $picInfo['height']-1, $bgColor)) {
    echo " Unable to create background ";  //@todo log 
    exit(0);
}
if (!@imagecopyresampled($new_img, $orgImg, ($picInfo['width']-$tW)/2, ($picInfo['height']-$tH)/2, 0, 0, $tW, $tH, $owidth, $oheight)) {
    echo " Failed to generate image ";
    exit(0);
}
// Generate images 
ob_start();
imagejpeg($new_img);
$_newImg = ob_get_contents();
ob_end_clean();
file_put_contents($imagePath.$picInfo['name']."/".$imgName, $_newImg);
header("Content-type:image/jpeg; charset=utf-8");
imagejpeg($new_img);
?>

Use e handler when binding apache conf documentError 404 for this file.