如何用PHP GD创建鱼眼效果

php -m | grep -i gd

<?php
// 载入源图像
$src_image = imagecreatefromjpeg('source_image.jpg');

// 获取图像尺寸
$width = imagesx($src_image);
$height = imagesy($src_image);

// 创建空白目标图像
$dest_image = imagecreatetruecolor($width, $height);

// 遍历源图像的每个像素
for ($x = 0; $x < $width; $x++) {
    for ($y = 0; $y < $height; $y++) {
        // 获取源图像的像素颜色
        $rgb = imagecolorat($src_image, $x, $y);
        $r = ($rgb >> 16) & 0xFF;
        $g = ($rgb >> 8) & 0xFF;
        $b = $rgb & 0xFF;

        // 计算鱼眼效果的新坐标
        $new_x = $x - $width / 2;
        $new_y = $y - $height / 2;
        $distance = sqrt($new_x * $new_x + $new_y * $new_y);
        $angle = atan2($new_y, $new_x);
        $new_distance = $distance * 0.8; // 调整此值以控制鱼眼效果的强度
        $new_x = $width / 2 + $new_distance * cos($angle);
        $new_y = $height / 2 + $new_distance * sin($angle);

        // 如果新坐标在目标图像范围内，则设置相应的像素颜色
        if ($new_x >= 0 && $new_x < $width && $new_y >= 0 && $new_y < $height) {
            $new_rgb = imagecolorallocate($dest_image, $r, $g, $b);
            imagesetpixel($dest_image, $new_x, $new_y, $new_rgb);
        }
    }
}

// 输出目标图像
header('Content-Type: image/jpeg');
imagejpeg($dest_image);

// 销毁图像资源
imagedestroy($src_image);
imagedestroy($dest_image);
?>