PHP generated thumbnail class to support PNG transparent image sharing _php Tutorial

PHP generated thumbnail class for PNG transparent image sharing

This article mainly describes the support of PNG transparent images of PHP generated thumbnail class sharing, the code based on the GD2 graphics library, to enable PNG transparent images to generate thumbnails, the need for friends can refer to the next

Note: This feature relies on the GD2 graphics library

Recently to use PHP to generate thumbnails, find a bit online, found this article: PHP generated thumbnail image

After a trial, we found that there were several problems:

1. PNG images generated thumbnails are in JPG format

2. PNG images generated thumbnails without transparent (translucent) effect (filled with black background)

3, the code syntax is relatively old

So, on the basis of this version of the simple modification is optimized a bit.

PHP generated thumbnail class

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/* * Desc:resize Image (PNG, JPG, GIF) * Author: Ten years later, brother Lou * date:2014.11.13 */ Class Resizeimage { Type of picture Private $type; Actual width Private $width; Actual height Private $height; The width after the change Private $resize _width; The height after the change Private $resize _height; Whether or not to cut the map Private $cut; Source image Private $srcimg; Destination image Address Private $dstimg; Temporarily created images 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); Initializing an image $this->initi_img (); Destination image Address $this-Dst_img ($savePath); //-- $this->width = imagesx ($this->im); $this->height = Imagesy ($this->im); Creating images $this->newimg (); Imagedestroy ($this->im); } Private Function newimg () { The proportions of the altered image $resize _ratio = ($this->resize_width)/($this->resize_height); Ratio of actual images $ratio = ($this->width)/($this->height); if ($this->cut) { Crop chart $newimg = Imagecreatetruecolor ($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->resize_height, $this->width , (($this->width)/$resize _ratio)); } } else { Do not cut the map if ($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)/$ratio, $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_height, $ This->width, $this->height); } } if ($this->type== "png") { Imagesavealpha ($newimg, true); Imagepng ($newimg, $this->dstimg); } else { Imagejpeg ($newimg, $this->dstimg); } } Initializing an image Private Function initi_img () { if ($this->type== "jpg") { $this->im = imagecreatefromjpeg ($this->srcimg); } 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 is as follows:

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

Parameters
$imgPath: Original image Address

$width: Thumbnail width

$height: High thumbnail image

$isCut: Whether clipping, bool value

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

Example

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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

http://www.bkjia.com/PHPjc/955276.html www.bkjia.com true http://www.bkjia.com/PHPjc/955276.html techarticle support PNG transparent image of PHP generated thumbnail class sharing this article mainly introduces the support of PNG transparent images of PHP generated thumbnail class sharing, this article code based on the GD2 Graphics library, the implementation of PNG transparency support ...

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