我正在尝试修改上传脚本，现在我可以在调整大小的同时将图像裁剪成正方形-太棒了！
然而，我希望用户能够上传任何大小的图像，并让脚本创建200x150、400x300、800x600的缩略图/图像，比例为4:3。
到目前为止，我的代码是：
list($width,$height) = getimagesize($uploadedfile);
if ($thumb == 1){
if ($width > $height) {
$y = 0;
$x = ($width - $height) / 2;
$smallestSide = $height;
} else {
$x = 0;
$y = ($height - $width) / 2;
$smallestSide = $width;
}
// copying the part into thumbnail
$thumbSize = 200;
$tmp = imagecreatetruecolor($thumbSize, $thumbSize);
imagecopyresampled($tmp, $src, 0, 0, $x, $y, $thumbSize, $thumbSize, $smallestSide, $smallestSide);
// write thumbnail to disk
$write_thumbimage = $folder .'/thumb-'. $image;
switch($ext){
case "gif":
imagegif($tmp,$write_thumbimage);
break;
case "jpg":
imagejpeg($tmp,$write_thumbimage,100);
break;
case "jpeg":
imagejpeg($tmp,$write_thumbimage,100);
break;
case "png":
imagepng($tmp,$write_thumbimage);
break;
}
有人知道所需的公式吗？或者能为我指明正确的方向吗？
使用C#副本上的一些内容来计算逻辑：
$thumb_width = 200;
$thumb_height = 150;
$original_aspect = $width / $height;
$thumb_aspect = $thumb_width / $thumb_height;
if ( $original_aspect >= $thumb_aspect ) {
$new_height = $thumb_height;
$new_width = $width / ($height / $thumb_height);
} else {
$new_width = $thumb_width;
$new_height = $height / ($width / $thumb_width);
}
$tmp = imagecreatetruecolor( $thumb_width, $thumb_height );
// Resize and crop
imagecopyresampled($tmp,
$src,
0 - ($new_width - $thumb_width) / 2, // Center the image horizontally
0 - ($new_height - $thumb_height) / 2, // Center the image vertically
0, 0,
$new_width, $new_height,
$width, $height);