PHP實現圖片上傳並壓縮_php技巧

本文執行個體講解了PHP圖片上傳並壓縮的實現方法，分享給大家供大家參考，具體內容如下

使用到三個檔案

• connect.php：串連資料庫
• test_upload.php：執行SQL語句
• upload_img.php：上傳圖片並壓縮
  

三個檔案代碼如下：
串連資料庫：connect.php

<?php$db_host = '';$db_user = '';$db_psw = '';$db_name = '';$db_port = '';$sqlconn=new mysqli($db_host,$db_user,$db_psw,$db_name);$q="set names utf8;";$result=$sqlconn->query($q);if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit();}?>

執行SQL語句：test_upload.php

<?phprequire ("connect.php");require ("upload_img.php");$real_img=$uploadfile; $small_img=$uploadfile_resize;$insert_sql = "insert into img (real_img,small_img) values (?,?)";$result = $sqlconn -> prepare($insert_sql);$result -> bind_param("ss", $real_img,$small_img);$result -> execute();?>

上傳圖片並壓縮：upload_img.php

<?php //設定檔案儲存目錄$uploaddir = "upfiles/"; //設定允許上傳檔案的類型$type=array("jpg","gif","bmp","jpeg","png"); //擷取檔案尾碼名函數 function fileext($filename) {  return substr(strrchr($filename, '.'), 1); } //產生隨機檔案名稱函數 function random($length) {  $hash = 'CR-';  $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';  $max = strlen($chars) - 1;  mt_srand((double)microtime() * 1000000);  for($i = 0; $i < $length; $i++)  {   $hash .= $chars[mt_rand(0, $max)];  }  return $hash; } $a=strtolower(fileext($_FILES['filename']['name'])); //判斷檔案類型 if(!in_array(strtolower(fileext($_FILES['filename']['name'])),$type)) {  $text=implode(",",$type);  $ret_code=3;//檔案類型錯誤 $page_result=$text; $retArray = array('ret_code' => $ret_code,'page_result'=>$page_result); $retJson = json_encode($retArray); echo $retJson; return;} //產生目標檔案的檔案名稱 else{  $filename=explode(".",$_FILES['filename']['name']);  do  {   $filename[0]=random(10); //設定隨機數長度   $name=implode(".",$filename);   //$name1=$name.".Mcncc";   $uploadfile=$uploaddir.$name;  }  while(file_exists($uploadfile));  if (move_uploaded_file($_FILES['filename']['tmp_name'],$uploadfile))  {   if(is_uploaded_file($_FILES['filename']['tmp_name']))   {   $ret_code=1;//上傳失敗  }  else  {//上傳成功  $ret_code=0; }  } $retArray = array('ret_code' => $ret_code);$retJson = json_encode($retArray);echo $retJson;}//壓縮圖片$uploaddir_resize="upfiles_resize/";$uploadfile_resize=$uploaddir_resize.$name;//$pic_width_max=120;//$pic_height_max=90;//以上與下面段注釋可以聯合使用，可以使圖片根據計算出來的比例壓縮$file_type=$_FILES["filename"]['type'];function ResizeImage($uploadfile,$maxwidth,$maxheight,$name){ //取得當前圖片大小 $width = imagesx($uploadfile); $height = imagesy($uploadfile); $i=0.5; //產生縮圖的大小 if(($width > $maxwidth) || ($height > $maxheight)) {  /*  $widthratio = $maxwidth/$width;  $heightratio = $maxheight/$height;    if($widthratio < $heightratio)  {   $ratio = $widthratio;  }  else  {    $ratio = $heightratio;  }    $newwidth = $width * $ratio;  $newheight = $height * $ratio;  */  $newwidth = $width * $i;  $newheight = $height * $i;  if(function_exists("imagecopyresampled"))  {   $uploaddir_resize = imagecreatetruecolor($newwidth, $newheight);   imagecopyresampled($uploaddir_resize, $uploadfile, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);  }  else  {   $uploaddir_resize = imagecreate($newwidth, $newheight);   imagecopyresized($uploaddir_resize, $uploadfile, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);  }    ImageJpeg ($uploaddir_resize,$name);  ImageDestroy ($uploaddir_resize); } else {  ImageJpeg ($uploadfile,$name); }}if($_FILES["filename"]['size']){ if($file_type == "image/pjpeg"||$file_type == "image/jpg"|$file_type == "image/jpeg") {  //$im = imagecreatefromjpeg($_FILES[$upload_input_name]['tmp_name']);  $im = imagecreatefromjpeg($uploadfile); } elseif($file_type == "image/x-png") {  //$im = imagecreatefrompng($_FILES[$upload_input_name]['tmp_name']);  $im = imagecreatefromjpeg($uploadfile); } elseif($file_type == "image/gif") {  //$im = imagecreatefromgif($_FILES[$upload_input_name]['tmp_name']);  $im = imagecreatefromjpeg($uploadfile); } else//預設jpg {  $im = imagecreatefromjpeg($uploadfile); } if($im) {  ResizeImage($im,$pic_width_max,$pic_height_max,$uploadfile_resize);   ImageDestroy ($im); }} ?>

請按照現實情況更改connect.php，test_upload.php中對應的資訊。

以上就是PHP實現圖片上傳並壓縮的方法，希望對大家的學習php程式設計有所協助