PHP-generated thumbnail classes that support PNG transparent images share _php tips

Note: This feature relies on the GD2 graphics library

Recently to use PHP to generate thumbnails, looked up on the internet, found this article: PHP generated thumbnail images

After a trial, there are several problems:

1, PNG image generated thumbnail is jpg format

2, the PNG image generated by the thumbnail does not have a transparent (translucent) effect (filled with a black background)

3, the code syntax is relatively old

So, on the basis of this version, simple modifications are optimized.

PHP Generate thumbnail class

<?php/* desc:resize Image (PNG, JPG, GIF) * Author: Ten years later, Lu Brother date:2014.11.13 * * Class Resizeimage
    {//Picture type private $type;
    Actual width private $width;
    The actual height of private $height;
    The width of the change after the private $resize _width;
    After changing the height of the private $resize _height;
    Whether the drawing is private $cut;
    source image private $srcimg;
    Target image address private $dstimg;

    A temporary image created by private $im;
      function __construct ($imgPath, $width, $height, $isCut, $savePath) {$this->srcimg = $imgPath;
      $this->resize_width = $width;
      $this->resize_height = $height;
      $this->cut = $isCut;

      Type of picture $this->type = Strtolower (substr (STRRCHR ($this->srcimg, "."), 1));
      Initialization of Image $this->initi_img ();
      The target image address $this-> dst_img ($savePath);
      --$this->width = Imagesx ($this->im);
      $this->height = Imagesy ($this->im);
      Generating Image $this->newimg (); Imagedestroy ($thiS-&GT;IM); Private Function Newimg () {//The proportions of the altered image $resize _ratio = ($this->resize_width)/($this->resize_heig
      HT);
      The proportions of the actual image $ratio = ($this->width)/($this->height);
        if ($this->cut) {//Map $newimg = Imagecreatetruecolor ($this->resize_width, $this->resize_height);
        if ($this->type== "png") {Imagefill ($newimg, 0, 0, Imagecolorallocatealpha ($newimg, 0, 0, 0, 127)); } if ($ratio >= $resize _ratio) {//High priority imagecopyresampled ($newimg, $this->im, 0, 0,
        0, 0, $this->resize_width, $this->resize_height, (($this->height) * $resize _ratio), $this->height); else {//Width first imagecopyresampled ($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, $this-&G
        T;resize_height, $this->width, (($this->width)/$resize _ratio)); } else {//Do not map if ($ratio >= $resize _ratio) {$newimg = ImagecreateTrueColor ($this->resize_width, ($this->resize_width)/$ratio);
          if ($this->type== "png") {Imagefill ($newimg, 0, 0, Imagecolorallocatealpha ($newimg, 0, 0, 0, 127)); Imagecopyresampled ($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, ($this->resize_width)/$rat
        Io, $this->width, $this->height);
          else {$newimg = Imagecreatetruecolor ($this->resize_height) * $ratio, $this->resize_height);
          if ($this->type== "png") {Imagefill ($newimg, 0, 0, Imagecolorallocatealpha ($newimg, 0, 0, 0, 127)); Imagecopyresampled ($newimg, $this->im, 0, 0, 0, 0, ($this->resize_height) * $ratio, $this->resize_he
        ight, $this->width, $this->height);
        } if ($this->type== "png") {Imagesavealpha ($newimg, true);
      Imagepng ($newimg, $this->dstimg);
      else {imagejpeg ($newimg, $this->dstimg);
    }//Initialize imagePrivate Function initi_img () {if ($this->type== "jpg") {$this->im = imagecreatefromjpeg ($this->srci
      MG);
      } if ($this->type== "gif") {$this->im = imagecreatefromgif ($this->srcimg);
      } if ($this->type== "png") {$this->im = imagecreatefrompng ($this->srcimg);

      }//Image Destination Address private function dst_img ($dstpath) {$full _length = strlen ($this->srcimg);
      $type _length = strlen ($this->type);


      $name _length = $full _length-$type _length;
      $name = substr ($this->srcimg,0, $name _length-1);
    $this->dstimg = $dstpath;

 }}?>

Use

When used, the constructor of the class is called directly, and the constructor functions as follows:

$resizeimage = new Resizeimage ($imgPath, $width, $height, $isCut, $savePath);

Parameters
$imgPath: Original picture address

$width: Thumbnail width

$height: Thumbnail height

$isCut: Is trimmed, bool value

$savePath: Thumbnail address (can be the same as the original picture address)

Example

<?php
  include "resizeimage.php";

  JPG
  $jpgResize = new Resizeimage ("Img/test_1920_1200.jpg", "img/test_320_240.jpg");

  PNG
  $pngResize = new Resizeimage ("Img/test_1024_746.png", "img/test_320_240.png");

>

Effect