Thumbnail generation program

I always wanted to find a program for the thumbnail of an image on the Internet, but I still didn't find the program without deformation. Generally, the source image is scaled simply.
I think it may already exist, but I did not find it, so I can't write one by myself. In fact, it's not all written by myself,
On the basis of existing changes!
The source code is as follows:

<? Php
/*
* Copyright Description: This version is developed on the basis of "IEB_UPLOAD CLASS Ver 1.1".
* Image cropping will make the image distorted and distorted! I made changes based on the program, using data parameters and the original image
* Compare the file parameters (mainly the width and height) to obtain the proportional value. The scaled image is scaled in the same proportion as the original image. However
* The image is then taken from the center of the intermediate image to obtain the thumbnail. Of course, the image will be cropped, but it is minimized.
* Crop!
* Programming: swin. wang Email: php_in_china@yahoo.com.cn QQ: 592298893
*
* You can use this program without restrictions, but please keep the copyright information
×
× Illegal use:
* $ Upfos = new ieb_upload ('photo _ file', './up_img'); name of the photo_file form file. Do not add $;./up_img to the upload location.
* $ Old_file_name = $ upfos-> getName ();
* $ Old_file_fooder = $ upfos-> getExt ();
* $ File_size = $ upfos-> getSize ();
* $ File_name = $ upfos-> newName ();
* $ Upfos-> upload ($ file_name );
* $ Upfos-> thumb ("small _", 125,120 );
* $ New_file_name = $ upfos-> UpFile (); $ new_file_name name of the uploaded big Image
× $ Small_file_name = "small _". $ new_file_name; $ small_file_name name
*/
Class ieb_upload {
Var $ FormName; // file domain name
Var $ Directroy; // upload to the Directory
Var $ MaxSize; // maximum upload size
Var $ CanUpload; // whether the file can be uploaded
Var $ doUpFile; // name of the uploaded file
Var $ sm_File; // The name of the thumbnail.
Var $ Error; // Error parameter

Function ieb_upload ($ formName = '', $ dirPath ='', $ maxSize = 2097152) // (1024*2) * 1024 = 2097152 is 2 M
{
Global $ FormName, $ Directroy, $ MaxSize, $ CanUpload, $ Error, $ doUpFile, $ sm_File;
// Initialize various parameters
$ FormName = $ formName;
$ MaxSize = $ maxSize;
$ CanUpload = true;
$ DoUpFile = '';
$ Sm_File = '';
$ Error = 0;
  
If ($ formName = ''){
$ CanUpload = false;
$ Error = 1;
Break;
   }
  
If ($ dirPath = ''){
$ Directroy = $ dirPath;
} Else {
$ Directroy = $ dirPath .'/';
  }
}

// Check whether the file exists
Function scanFile ()
{
Global $ FormName, $ Error, $ CanUpload;
  
If ($ CanUpload ){
  
$ Scan = is_readable ($ _ FILES [$ FormName] ['name']);
   
If ($ scan ){
$ Error = 2;
   }
   
Return $ scan;
  }
}


// Get the file size
Function getSize ($ format = 'B ')
{
Global $ FormName, $ Error, $ CanUpload;
  
If ($ CanUpload ){
  
If ($ _ FILES [$ FormName] ['size'] = 0 ){
$ Error = 3;
$ CanUpload = false;
   }
   
Switch ($ format ){
Case 'B ':
Return $ _ FILES [$ FormName] ['size'];
Break;
   
Case'm ':
Return ($ _ FILES [$ FormName] ['size'])/(1024*1024 );
   }
   
  }
}

// Obtain the file type
Function getExt ()
{
Global $ FormName, $ Error, $ CanUpload;
  
If ($ CanUpload ){
$ Ext = $ _ FILES [$ FormName] ['name'];
$ ExtStr = explode ('.', $ ext );
$ Count = count ($ extStr)-1;
  }
Return $ extStr [$ count];
}

// Obtain the file name
Function getName ()
{
Global $ FormName, $ CanUpload;
  
If ($ CanUpload ){
Return $ _ FILES [$ FormName] ['name'];
  }
}

// Create a file name
Function newName ()
{
Global $ CanUpload, $ FormName;
  
If ($ CanUpload ){
$ FullName = $ _ FILES [$ FormName] ['name'];
$ ExtStr = explode ('.', $ FullName );
$ Count = count ($ extStr)-1;
$ Ext = $ extStr [$ count];
   
Return date ('ymdhis '). rand ().'. '. $ ext;
  }
}

// Upload a file
Function upload ($ fileName = '')
{
Global $ FormName, $ Directroy, $ CanUpload, $ Error, $ doUpFile;
  
If ($ CanUpload ){
If ($ _ FILES [$ FormName] ['size'] = 0 ){
$ Error = 3;
$ CanUpload = false;
Return $ Error;
Break;
   }
  }
  
If ($ CanUpload ){
  
If ($ fileName = ''){
$ FileName = $ _ FILES [$ FormName] ['name'];
   }
      
$ DoUpload = @ copy ($ _ FILES [$ FormName] ['tmp _ name'], $ Directroy. $ fileName );
   
If ($ doUpload)
   {
$ DoUpFile = $ fileName;
Chmod ($ Directroy. $ fileName, 0777 );
Return true;
} Else {
$ Error = 4;
Return $ Error;
   }
  }
}

// Create an image thumbnail
Function thumb ($ dscChar = '', $ width = 160, $ height = 120)
{
Global $ CanUpload, $ Error, $ Directroy, $ doUpFile, $ sm_File;
  
If ($ CanUpload & $ doUpFile! = ''){
$ SrcFile = $ doUpFile;
   
If ($ dscChar = ''){
$ DscChar = 'SM _';
   }
   
$ DscFile = $ Directroy. $ dscChar. $ srcFile;
$ Data = getimagesize ($ Directroy. $ srcFile, & $ info );
   
Switch ($ data [2]) {
Case 1:
$ Im = @ imagecreatefromgif ($ Directroy. $ srcFile );
Break;
   
Case 2:
$ Im = @ imagecreatefromjpeg ($ Directroy. $ srcFile );
Break;
   
Case 3:
$ Im = @ imagecreatefrompng ($ Directroy. $ srcFile );
Break;
   }
   
$ SrcW = imagesx ($ im );
$ SrcH = imagesy ($ im );
   
If ($ srcW/$ width) >=( $ srcH/$ height )){
$ Temp_height = $ height;
$ Temp_width = $ srcW/($ srcH/$ height );
$ Src_X = abs ($ width-$ temp_width)/2 );
$ Src_Y = 0;
        }
Else {
$ Temp_width = $ width;
$ Temp_height = $ srcH/($ srcW/$ width );
$ Src_X = 0;
$ Src_Y = abs ($ height-$ temp_height)/2 );
                }
$ Temp_img = imagecreatetruecolor ($ temp_width, $ temp_height );
Imagecopyresized ($ temp_img, $ im, 0, 0, 0, $ temp_width, $ temp_height, $ srcW, $ srcH );
       
       
$ Ni = imagecreatetruecolor ($ width, $ height );
Imagecopyresized ($ ni, $ temp_img, 0, 0, $ src_X, $ src_Y, $ width, $ height, $ width, $ height );
$ Cr = imagejpeg ($ ni, $ dscFile );
Chmod ($ dscFile, 0777 );
          
  
If ($ cr ){
$ Sm_File = $ dscFile;
Return true;
} Else {
$ Error = 5;
Return $ Error;
   }
  }
}

// Display error parameters
Function Err (){
Global $ Error;
Return $ Error;
}

// Name of the uploaded file
Function UpFile (){
Global $ doUpFile, $ Error;
If ($ doUpFile! = ''){
Return $ doUpFile;
} Else {
$ Error = 6;
  }
}

// File Upload path
Function filePath (){
Global $ Directroy, $ doUpFile, $ Error;
If ($ doUpFile! = ''){
Return $ Directroy. $ doUpFile;
} Else {
$ Error = 6;
  }  
}

// Thumbnail file name
Function thumbMap (){
Global $ sm_File, $ Error;
If ($ sm_File! = ''){
Return $ sm_File;
} Else {
$ Error = 6;
  }
}

// Display version information
Function ieb_version (){
Return 'swin img class Ver 0.1 ';
}
}
?>