PHP Advanced Features: Praktische Tipps zur Bildverarbeitung

// 缩放图像到宽度为 200px
$new_image = imagecreatetruecolor(200, 100);
imagecopyresampled($new_image, $image, 0, 0, 0, 0, 200, 100, imagesx($image), imagesy($image));

// 裁剪图像中心区域为正方形
$new_width = imagesx($image) / 2;
$new_height = imagesy($image) / 2;
$new_image = imagecrop($image, ['x' => $new_width / 2, 'y' => $new_height / 2, 'width' => $new_width, 'height' => $new_height]);

// 将水印图像叠加到原始图像上
$watermark = imagecreatefrompng('watermark.png');

// 调整水印位置和透明度
imagecopymerge_alpha($image, $watermark, 0, 0, 0, 0, imagesx($image), imagesy($image), 50);

// 保存具有水印的图像
imagepng($image, 'watermarked_image.png');

// 给图像应用高斯模糊滤镜
imagefilter($image, IMG_FILTER_GAUSSIAN_BLUR);

// 使用自定义卷积内核锐化图像
$kernel = [[-1, -1, -1], [0, 0, 0], [1, 1, 1]];
imageconvolution($image, $kernel, 1, 0);

// 将图像从 JPEG 转换为 PNG
imagepng($image, 'converted_image.png');

// 将图像从 PNG 转换为 GIF
imagegif($image, 'converted_image.gif');

// 创建缩略图目录
mkdir('thumbnails');

// 获取所有图像文件
$images = glob('uploads/*.{jpg,png,gif}', GLOB_BRACE);

foreach ($images as $image) {
    // 获取图像元数据并计算缩略图尺寸
    $metadata = getimagesize($image);
    $width = $metadata[0];
    $height = $metadata[1];
    $thumb_width = 100;
    $thumb_height = 100;

    // 创建缩略图
    $thumb = imagecreatetruecolor($thumb_width, $thumb_height);
    imagecopyresampled($thumb, $image, 0, 0, 0, 0, $thumb_width, $thumb_height, $width, $height);

    // 将缩略图保存到指定目录
    switch ($metadata[2]) {
        case IMAGETYPE_JPEG:
            imagejpeg($thumb, 'thumbnails/' . basename($image));
            break;
        case IMAGETYPE_PNG:
            imagepng($thumb, 'thumbnails/' . basename($image));
            break;
        case IMAGETYPE_GIF:
            imagegif($thumb, 'thumbnails/' . basename($image));
            break;
        default:
            continue;
    }
}