PHP generates thumbnails and adds watermark_PHP tutorial-PHP Tutorial-php.cn

PHP generates thumbnails and adds watermark_PHP tutorial

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Release： 2016-07-14 10:07:20

Original

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This is a simple GD library operation

[php]

/****

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/***

Want to manipulate pictures

You must first get the size and type information of the image

Watermark: Copy the specified watermark to the target and add a transparent effect

Thumbnail: It is to copy a large picture to a small size screen

***/

class ImageTool {

// imageInfo analyzes image information

// return array()

public static function imageInfo($image) {

// Determine whether the image exists

if (!file_exists($image)) {

return false;

} }

$info = getimagesize($image);

if ($info == false) {

return false;

} }

// At this time, the info is analyzed and it is an array

$img['width'] = $info[0];

$img['height'] = $info[1];

$img['ext'] = substr($info['mime'], strpos($info['mime'], '/') + 1);

return $img;

}

Watermark function

parm String $dst and other operation pictures

parm String $water watermark image

parm String $save, if not filled in, the original image will be replaced by default

public static function water($dst, $water, $save = NULL, $pos = 2, $alpha = 50) {

// Make sure 2 pictures exist first

if (!file_exists($dst) || !file_exists($water)) {

return false;

} }

// First ensure that the watermark cannot be larger than the image to be operated

$dinfo = self::imageInfo($dst);

$winfo = self::imageInfo($water);

if ($winfo['height'] > $dinfo['height'] || $winfo['width'] > $dinfo['width']) {

return false;

} }

// Two pictures, read them on the canvas! But the pictures may be png or jpeg, what function should be used to read them?

$dfunc = 'imagecreatefrom' . $dinfo['ext'];

$wfunc = 'imagecreatefrom' . $winfo['ext'];

if (!function_exists($dfunc) || !function_exists($wfunc)) {

return false;

} } www.2cto.com

// Dynamically load functions to create canvas

$dim = $dfunc($dst);

// Create the canvas to be operated

$wim = $wfunc($water);

// Create watermark canvas

// Calculate the pasted coordinates based on the location of the watermark

switch($pos) {

case 0 :

$posx = 0;

$posy = 0;

break;

case 1 :

// 右上角

$posx = $dinfo['width'] - $winfo['width'];

$posy = 0;

break;

case 3 :

// 左下角

$posx = 0;

$posy = $dinfo['height'] - $winfo['height'];

break;

default :

$posx = $dinfo['width'] - $winfo['width'];

$posy = $dinfo['height'] - $winfo['height'];

}

// 加水印

imagecopymerge($dim, $wim, $posx, $posy, 0, 0, $winfo['width'], $winfo['height'], $alpha);

// 保存

if (!$save) {

$save = $dst;

unlink($dst);

// 删除原图

}

$createfunc = 'image' . $dinfo['ext'];

$createfunc($dim, $save);

imagedestroy($dim);

imagedestroy($wim);

return true;

}

/**

Thumb Generate thumbnails

Scale proportionally, leave blank on both sides

**/

public static function thumb($dst, $save = NULL, $width = 200, $height = 200) {

// 首先判断待处理的图片存不存在

$dinfo = self::imageInfo($dst);

if ($dinfo == false) {

return false;

}

// 计算缩放比例

$calc = min($width / $dinfo['width'], $height / $dinfo['height']);

// 创建原始图的画布

$dfunc = 'imagecreatefrom' . $dinfo['ext'];

$dim = $dfunc($dst);

// 创建缩略画布

$tim = imagecreatetruecolor($width, $height);

// 创建白色填充缩略画布

$white = imagecolorallocate($tim, 255, 255, 255);

// 填充缩略画布

imagefill($tim, 0, 0, $white);

// 复制并缩略

$dwidth = (int)$dinfo['width'] * $calc;

$dheight = (int)$dinfo['height'] * $calc;

$paddingx = (int)($width - $dwidth) / 2;

$paddingy = (int)($height - $dheight) / 2;

imagecopyresampled($tim, $dim, $paddingx, $paddingy, 0, 0, $dwidth, $dheight, $dinfo['width'], $dinfo['height']);

// 保存图片

if (!$save) {

$save = $dst;

unlink($dst);

}

$createfunc = 'image' . $dinfo['ext'];

$createfunc($tim, $save);

imagedestroy($dim);

imagedestroy($tim);

return true;

}

// print_r(ImageTool::imageInfo('./home.jpg'));

/* www.2cto.com

echo ImageTool::water('./home.jpg','./smallfeng.png','home1.jpg',0)?'OK':'FAIL';

echo ImageTool::water('./home.jpg','./smallfeng.png','home2.jpg',1)?'OK':'FAIL';

echo ImageTool::water('./home.jpg','./smallfeng.png','home3.jpg',2)?'OK':'FAIL';

echo ImageTool::water('./home.jpg','./smallfeng.png','home4.jpg',3)?'OK':'FAIL';