最近准备弄一个图床，既然是图床就需要能对图片进行一些常用的操作，比如水印，转换格式，生成缩略图等，前几天刚好接触了 PHP 的 GD 库，于是便花了点时间封装了这个简单的图片处理函数。
/**
* 将图片转换为webp或其他格式，同时可以添加水印
*
* @author Otstar Lin
*
* @param String $source 原图片地址
* @param String $type 转换后图片格式
* @param String $to 转换后图片地址 若为 null 则代表直接输出到浏览器
* @param Array $thumbnail_size 缩略图尺寸
* @param Integer $thum 要输出到浏览器的图片，当 $to == null 的时候生效, -1 代表使用原尺寸图，其他数字分别代表使用 $thumbnail_size 指定索引的尺寸图
* @param Boolean $watermark 是否加水印
* @param Integer $watermark_type 水印格式 1：文字 2：图片
* @param String $watermark_content 水印内容，若为图片则是水印图片地址
* @param Integer $position 水印位置
* @param Integer $alpha 水印透明度
* @param Array $color 水印内容颜色
* @param Integer $font_size 水印文字大小
* @param String $font_name 水印字体地址
*/
function image_change($source, $type='webp', $to = null, $thumbnail_size = [], $thum = -1,
$watermark = false, $watermark_type = 1, $watermark_content = '', $position = 9,
$alpha = 0, $color = [0, 0, 0], $font_size = 14, $font_name = 'Roboto-Medium.ttf')
{
$image = imagecreatefromstring(file_get_contents($source));
// 生成水印
if($watermark) {
// 获取原图信息
$image_info = getimagesize($source);
// 设置颜色
$content_color = imagecolorallocatealpha($image, $color[0], $color[1], $color[2], $alpha);
// 载入字体
putenv('GDFONTPATH=' . realpath('.'));
$font = $font_name;
$left = 0;
$top = 0;
// 获取水印占据的空间大小
$watermark_content_info = [];
if($watermark_type == 1) {
$temp = imagettfbbox($font_size, 0, $font_name, $watermark_content);
$watermark_content_info[] = $temp[2] - $temp[0];
$watermark_content_info[] = $temp[1] - $temp[7];
} else {
$temp = getimagesize($watermark_content);
$watermark_content_info[] = $temp[0];
$watermark_content_info[] = $temp[1];
}
// 对水印进行定位
switch($position) {
case 1:
$left = 20;
$top = 20;
break;
case 2:
$left = $image_info[0]/2 - $watermark_content_info[0]/2;
$top = 20;
break;
case 3:
$left = $image_info[0] - $watermark_content_info[0] - 20;
$top = 20;
break;
case 4:
$left = 20;
$top = $image_info[1]/2 - $watermark_content_info[1]/2;
break;
case 5:
$left = $image_info[0]/2 - $watermark_content_info[0]/2;
$top = $image_info[1]/2 - $watermark_content_info[1]/2;
break;
case 6:
$left = $image_info[0] - $watermark_content_info[0] - 20;
$top = $image_info[1]/2 - $watermark_content_info[1]/2;
break;
case 7:
$left = 20;
$top = $image_info[1] - $watermark_content_info[1] - 20;
break;
case 8:
$left = $image_info[0]/2 - $watermark_content_info[0]/2;
$top = $image_info[1] - $watermark_content_info[1] - 20;
break;
case 9:
$left = $image_info[0] - $watermark_content_info[0] - 20;
$top = $image_info[1] - $watermark_content_info[1] - 20;
break;
}
// 对文字水印和图片水印进行不同的处理
if($watermark_type == 1) {
imagettftext($image, $font_size, 0, $left, $font_size + $top, $content_color, $font, $watermark_content);
} else {
$watermark_image = imagecreatefromstring(file_get_contents($watermark_content));
imagecopy($image, $watermark_image, $left, $top, 0, 0, $watermark_content_info[0], $watermark_content_info[1]);
}
}
// 获取图片文件名（去除后缀）
$image_pathinfo = pathinfo($source);
$image_name = str_replace('.'.$image_pathinfo['extension'], '', $image_pathinfo['basename']);
$path = null;
// 输出原图
if($to === null) {
header('Content-type:image/'.$type);
} else {
$path = $to.$image_name.'.'.$type;
}
if($type == 'jepg') {
if($thum == -1) imagejpeg($image, $path);
} else if($type == 'png') {
if($thum == -1) imagepng($image, $path);
} else {
if($thum == -1) imagewebp($image, $path);
}
// 输出缩略图
foreach ($thumbnail_size as $num => $size) {
$set = true;
if(!isset($size['height'])) {
$set = false;
$size['height'] = $size['width'] * $image_info[1]/$image_info[0];
}
$thum_img = imagecreatetruecolor($size['width'], $size['height']);
imagecopyresampled($thum_img, $image, 0, 0, 0, 0, $size['width'], $size['height'], $image_info[0], $image_info[1]);
if($to !== null) {
if($type == 'jepg') {
imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
} else if($type == 'png') {
imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
} else {
imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
}
} else {
if($num == $thum) {
if($type == 'jepg') {
imagewebp($thum_img);
} else if($type == 'png') {
imagewebp($thum_img);
} else {
imagewebp($thum_img);
}
}
}
}
}
// 缩略图的尺寸
$thum = [
[
'width' => 200,
],
[
'width' => 400,
'height' => 200
]
];
image_change('img.png', 'webp', '', $thum, -1, true, 1, 'Otstar Lin', 9, 0);/**
* 将图片转换为webp或其他格式，同时可以添加水印
*
* @author Otstar Lin
*
* @param String $source 原图片地址
* @param String $type 转换后图片格式
* @param String $to 转换后图片地址 若为 null 则代表直接输出到浏览器
* @param Array $thumbnail_size 缩略图尺寸
* @param Integer $thum 要输出到浏览器的图片，当 $to == null 的时候生效, -1 代表使用原尺寸图，其他数字分别代表使用 $thumbnail_size 指定索引的尺寸图
* @param Boolean $watermark 是否加水印
* @param Integer $watermark_type 水印格式 1：文字 2：图片
* @param String $watermark_content 水印内容，若为图片则是水印图片地址
* @param Integer $position 水印位置
* @param Integer $alpha 水印透明度
* @param Array $color 水印内容颜色
* @param Integer $font_size 水印文字大小
* @param String $font_name 水印字体地址
*/
function image_change($source, $type='webp', $to = null, $thumbnail_size = [], $thum = -1,
$watermark = false, $watermark_type = 1, $watermark_content = '', $position = 9,
$alpha = 0, $color = [0, 0, 0], $font_size = 14, $font_name = 'Roboto-Medium.ttf')
{
$image = imagecreatefromstring(file_get_contents($source));
// 生成水印
if($watermark) {
// 获取原图信息
$image_info = getimagesize($source);
// 设置颜色
$content_color = imagecolorallocatealpha($image, $color[0], $color[1], $color[2], $alpha);
// 载入字体
putenv('GDFONTPATH=' . realpath('.'));
$font = $font_name;
$left = 0;
$top = 0;
// 获取水印占据的空间大小
$watermark_content_info = [];
if($watermark_type == 1) {
$temp = imagettfbbox($font_size, 0, $font_name, $watermark_content);
$watermark_content_info[] = $temp[2] - $temp[0];
$watermark_content_info[] = $temp[1] - $temp[7];
} else {
$temp = getimagesize($watermark_content);
$watermark_content_info[] = $temp[0];
$watermark_content_info[] = $temp[1];
}
// 对水印进行定位
switch($position) {
case 1:
$left = 20;
$top = 20;
break;
case 2:
$left = $image_info[0]/2 - $watermark_content_info[0]/2;
$top = 20;
break;
case 3:
$left = $image_info[0] - $watermark_content_info[0] - 20;
$top = 20;
break;
case 4:
$left = 20;
$top = $image_info[1]/2 - $watermark_content_info[1]/2;
break;
case 5:
$left = $image_info[0]/2 - $watermark_content_info[0]/2;
$top = $image_info[1]/2 - $watermark_content_info[1]/2;
break;
case 6:
$left = $image_info[0] - $watermark_content_info[0] - 20;
$top = $image_info[1]/2 - $watermark_content_info[1]/2;
break;
case 7:
$left = 20;
$top = $image_info[1] - $watermark_content_info[1] - 20;
break;
case 8:
$left = $image_info[0]/2 - $watermark_content_info[0]/2;
$top = $image_info[1] - $watermark_content_info[1] - 20;
break;
case 9:
$left = $image_info[0] - $watermark_content_info[0] - 20;
$top = $image_info[1] - $watermark_content_info[1] - 20;
break;
}
// 对文字水印和图片水印进行不同的处理
if($watermark_type == 1) {
imagettftext($image, $font_size, 0, $left, $font_size + $top, $content_color, $font, $watermark_content);
} else {
$watermark_image = imagecreatefromstring(file_get_contents($watermark_content));
imagecopy($image, $watermark_image, $left, $top, 0, 0, $watermark_content_info[0], $watermark_content_info[1]);
}
}
// 获取图片文件名（去除后缀）
$image_pathinfo = pathinfo($source);
$image_name = str_replace('.'.$image_pathinfo['extension'], '', $image_pathinfo['basename']);
$path = null;
// 输出原图
if($to === null) {
header('Content-type:image/'.$type);
} else {
$path = $to.$image_name.'.'.$type;
}
if($type == 'jepg') {
if($thum == -1) imagejpeg($image, $path);
} else if($type == 'png') {
if($thum == -1) imagepng($image, $path);
} else {
if($thum == -1) imagewebp($image, $path);
}
// 输出缩略图
foreach ($thumbnail_size as $num => $size) {
$set = true;
if(!isset($size['height'])) {
$set = false;
$size['height'] = $size['width'] * $image_info[1]/$image_info[0];
}
$thum_img = imagecreatetruecolor($size['width'], $size['height']);
imagecopyresampled($thum_img, $image, 0, 0, 0, 0, $size['width'], $size['height'], $image_info[0], $image_info[1]);
if($to !== null) {
if($type == 'jepg') {
imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
} else if($type == 'png') {
imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
} else {
imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
}
} else {
if($num == $thum) {
if($type == 'jepg') {
imagewebp($thum_img);
} else if($type == 'png') {
imagewebp($thum_img);
} else {
imagewebp($thum_img);
}
}
}
}
}
// 缩略图的尺寸
$thum = [
[
'width' => 200,
],
[
'width' => 400,
'height' => 200
]
];
image_change('img.png', 'webp', '', $thum, -1, true, 1, 'Otstar Lin', 9, 0);PHP GD图片处理[转换格式-水印-缩略图]
https://blog.ixk.me/post/php-gd-image-processing许可协议
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本文作者
Otstar Lin
发布于
2019/02/14
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