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PHP GD图片处理[转换格式-水印-缩略图]

2019/02/14 (已编辑)折腾记录#PHP / #PHP-GD

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

    BY-NC-SA

  • 本文作者

    Otstar Lin

  • 发布于

    2019/02/14

转载或引用本文时请遵守许可协议，注明出处、不得用于商业用途！

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