PHP图像调整大小会裁剪图像的一部分，而不是调整大小

Question

我正在网站上上传一些图像。但是我也想以较小尺寸的那些图像进行复制。我已经四处搜寻，并想出了以下代码。问题在于，它没有创建图像的较小版本，而是仅占据了图像的一部分。我认为它的左上角。有人看到我错过的问题吗？图片通过POST传递

<?php
    include "connect.php";
    $uploaddir = '../img/avatars/';
    $uploaddir35 = '../img/avatars/35x35/';
    $uploaddir50 = '../img/avatars/50x50/';
    $uploaddir100 = '../img/avatars/100x100/';
    $uploaddir140 = '../img/avatars/140x140/';
    $dimension35  = 35;
    $dimension50  = 50;
    $dimension100 = 100;
    $dimension140 = 140;

    $filename=$_FILES['file']['name'];
    $ext = pathinfo($filename, PATHINFO_EXTENSION);
    $file_name=$_SESSION['user_ID']."_".time().".".$ext;
    $uploadfile = $uploaddir.$file_name;



    if (move_uploaded_file($_FILES['file']['tmp_name'], $uploadfile)) {
        echo $uploadfile;
        $_SESSION['img']=$file_name;
        $query="UPDATE user
            SET img='$file_name'
            WHERE ID='".$_SESSION['user_ID']."'";
        mysqli_query($con,$query);
    } else {
        echo "Upload failed";
        echo 'Here is some more debugging info:';
        print_r($_FILES);
    }
    //make small imges
    $file_name = $_FILES['file']['tmp_name'];
    $target_filename=$_SESSION['user_ID']."_".time().".".$ext;
    list($width, $height, $type, $attr) = getimagesize( $file_name );
    $src = imagecreatefromjpeg(file_get_contents($file_name));
    //35x35
    $dst = imagecreatetruecolor($dimension35,$dimension35);
    imagecopyresampled( $dst, $src, 0, 0, 0, 0, $dimension35, $dimension35, $width, $height );
    imagejpeg($dst, $uploaddir35.$target_filename );
    imagedestroy( $dst );
    //50x50
    $dst = imagecreatetruecolor($dimension50,$dimension50);
    imagecopyresampled( $dst, $src, 0, 0, 0, 0, $dimension50, $dimension50, $width, $height );
    imagejpeg($dst, $uploaddir50.$target_filename );
    imagedestroy( $dst );
    //100x100
    $dst = imagecreatetruecolor($dimension100,$dimension100);
    imagecopyresampled( $dst, $src, 0, 0, 0, 0, $dimension100, $dimension100, $width, $height );
    imagejpeg($dst, $uploaddir100.$target_filename );
    imagedestroy( $dst );
    //140x140
    $dst = imagecreatetruecolor($dimension140,$dimension140);
    imagecopyresampled( $dst, $src, 0, 0, 0, 0, $dimension140, $dimension140, $width, $height );
    imagejpeg($dst, $uploaddir140.$target_filename );
    imagedestroy( $dst );
?>