一、图片上传

1.1 准备工作

首先,确保你的服务器已安装PHP和GD库。GD库是PHP处理图像的扩展库,用于生成、编辑和处理图像。

1.2 上传表单

<form action="upload.php" method="post" enctype="multipart/form-data">
    <label for="image">选择图片:</label>
    <input type="file" name="image" id="image" required>
    <input type="submit" value="上传">
</form>

1.3 PHP上传处理

<?php
if (isset($_FILES['image'])) {
    $image = $_FILES['image'];
    $filename = $image['name'];
    $tmp_name = $image['tmp_name'];
    $error = $image['error'];

    if ($error === 0) {
        $allowed = array('jpg', 'jpeg', 'gif', 'png');
        $ext = strtolower(end(explode('.', $filename)));
        if (in_array($ext, $allowed)) {
            $new_filename = uniqid() . '.' . $ext;
            move_uploaded_file($tmp_name, 'uploads/' . $new_filename);
            echo "上传成功!图片路径:uploads/" . $new_filename;
        } else {
            echo "文件格式不正确。";
        }
    } else {
        echo "上传失败。错误代码:" . $error;
    }
}
?>

二、图片裁切

2.1 裁切工具

2.2 裁切示例

<?php
// 读取图片
$image = imagecreatefromjpeg('uploads/image.jpg');

// 裁切尺寸
$width = 100;
$height = 100;

// 裁切图片
$cut = imagecrop($image, ['x' => 50, 'y' => 50, 'width' => $width, 'height' => $height]);

// 保存裁切后的图片
imagejpeg($cut, 'uploads/cropped_image.jpg');

// 销毁图片资源
imagedestroy($image);
imagedestroy($cut);
?>

三、总结