Code sharing for generating picture thumbnails with PHP based on GD2 graphics library

Code sharing for generating picture thumbnails with PHP based on GD2 graphics library_PHP tutorial

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Release： 2016-07-13 10:07:31

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Sharing code for generating image thumbnails with PHP based on GD2 graphics library

This article mainly introduces sharing code for generating image thumbnails with PHP based on GD2 graphics library. This article directly The implementation code and usage methods are given, friends in need can refer to it

To use PHP to generate image thumbnails, make sure your PHP server has the GD2 graphics library installed. Use a class to generate image thumbnails

1. How to use

1 2	$resizeimage = new resizeimage("图片源文件地址", "200", "100", "0","缩略图地址"); //就只用上面的一句话,就能生成缩略图,其中,源文件和缩略图地址可以相同,200,100分别代表宽和高

1 2

$resizeimage = new resizeimage("Image source file address", "200", "100", "0","Thumbnail address"); // Just use the above sentence to generate a thumbnail. The source file and thumbnail addresses can be the same, 200 and 100 represent the width and height respectively

2. Thumbnail code

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//Use the following class to generate image thumbnails,

class resizeimage

{

//Picture type

var $type;

//Actual width

var $width;

//Actual height

var $height;

//Changed width

var $resize_width;

//Changed height

var $resize_height;

//Whether to crop the image

var $cut;

//Source image

var $srcimg;

//Target image address

var $dstimg;

//Temporarily created image

var $im;

function resizeimage($img, $wid, $hei,$c,$dstpath)

{

$this->srcimg = $img;

$this->resize_width = $wid;

$this->resize_height = $hei;

$this->cut = $c;

//Type of picture

$this->type = strtolower(substr(strrchr($this->srcimg,"."),1));

//Initialize image

$this->initi_img();

//Target image address

$this -> dst_img($dstpath);

//--

$this->width = imagesx($this->im);

$this->height = imagesy($this->im);

//Generate image

$this->newimg();

ImageDestroy ($this->im);

}

function newimg()

{

//The proportion of the changed image

$resize_ratio = ($this->resize_width)/($this->resize_height);

//Proportion of actual image

$ratio = ($this->width)/($this->height);

if(($this->cut)=="1")

//裁图

{

if($ratio>=$resize_ratio)

//高度优先

{

$newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);

imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width,$this->resize_height, (($this->height)*$resize_ratio), $this->height);

ImageJpeg ($newimg,$this->dstimg);

}

if($ratio<$resize_ratio)

//宽度优先

{

$newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);

imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, $this->resize_height, $this->width, (($this->width)/$resize_ratio));

ImageJpeg ($newimg,$this->dstimg);

}

else

//不裁图

{

if($ratio>=$resize_ratio)

{

$newimg = imagecreatetruecolor($this->resize_width,($this->resize_width)/$ratio);

imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, ($this->resize_width)/$ratio, $this->width, $this->height);

ImageJpeg ($newimg,$this->dstimg);

}

if($ratio<$resize_ratio)

{

$newimg = imagecreatetruecolor(($this->resize_height)*$ratio,$this->resize_height);

imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, ($this->resize_height)*$ratio, $this->resize_height, $this->width, $this->height);

ImageJpeg ($newimg,$this->dstimg);

}

//初始化图象

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);

}

//图象目标地址

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;

//echo $this->dstimg;

}