php在上传时或上传之前调整图像大小

2022-01-09 00:00:00 resize image upload php

在上传之前或上传期间如何调整图片大小?

how would i resize the image before or during the upload?

    <?php
     // Start a session for error reporting
    session_start();
    ?>
     <?php
    // Check, if username session is NOT set then this page will jump to login page
if (!isset($_SESSION['username'])) {
        header('Location: index.html');
        exit;
}
// *** Include the class
    include("resize-class.php");


// Call our connection file
include('config.php');

// Check to see if the type of file uploaded is a valid image type
function is_valid_type($file)
{
    // This is an array that holds all the valid image MIME types
    $valid_types = array("image/jpg", "image/JPG", "image/jpeg", "image/bmp", "image/gif", "image/png");

    if (in_array($file['type'], $valid_types))
        return 1;
    return 0;
}

// Just a short function that prints out the contents of an array in a manner that's easy to read
// I used this function during debugging but it serves no purpose at run time for this example
function showContents($array)
{
    echo "<pre>";
    print_r($array);
    echo "</pre>";
}

// Set some constants
// Grab the User ID we sent from our form
$user_id = $_SESSION['username'];
$category = $_POST['category'];

// This variable is the path to the image folder where all the images are going to be stored
// Note that there is a trailing forward slash
$TARGET_PATH = "img/users/$category/$user_id/";
if (! is_dir($TARGET_PATH)) {
    mkdir($TARGET_PATH, 0775, true);
}

// Get our POSTed variables
$fname = $_POST['fname'];
$lname = $_POST['lname'];
$contact = $_POST['contact'];
$price = $_POST['price'];
$conditional = $_POST['conditional'];
$image = $_FILES['image'];


// Build our target path full string.  This is where the file will be moved do
// i.e.  images/picture.jpg
$TARGET_PATH .= $image['name'];

// Make sure all the fields from the form have inputs
if ( $fname == "" || $lname == "" || $image['name'] == "" || $category['category'] == "" || $conditional['conditional'] == "" || $price['price'] == "" )
{
    $_SESSION['error'] = "All fields required";
    header("Location: securedpage1.php");
    exit;
}

// Check to make sure that our file is actually an image
// You check the file type instead of the extension because the extension can easily be faked
if (!is_valid_type($image))
{
    $_SESSION['error'] = "You must upload a jpeg, gif, or bmp";
    header("Location: securedpage1.php");
    exit;
}

// Here we check to see if a file with that name already exists
// You could get past filename problems by appending a timestamp to the filename and then continuing
if (file_exists($TARGET_PATH))
{
    $_SESSION['error'] = "A file with that name already exists";
    header("Location: securedpage1.php");
    exit;
}


// Lets attempt to move the file from its temporary directory to its new home
if (move_uploaded_file($image['tmp_name'], $TARGET_PATH))
{
    // NOTE: This is where a lot of people make mistakes.
    // We are *not* putting the image into the database; we are putting a reference to the file's location on the server

    $imagename = $image['name'];


    $sql = "insert into people (price, contact, category, username, fname, lname, expire, filename, conditional, posttime) values (:price, :contact, :category, :user_id, :fname, :lname, now() + INTERVAL 1 MONTH, :imagename, :conditional, now())";
                                $q = $conn->prepare($sql) or die("failed!");
                                $q->bindParam(':price', $price, PDO::PARAM_STR);
                                $q->bindParam(':contact', $contact, PDO::PARAM_STR);
                                $q->bindParam(':category', $category, PDO::PARAM_STR);
                                $q->bindParam(':user_id', $user_id, PDO::PARAM_STR);
                                $q->bindParam(':fname', $fname, PDO::PARAM_STR);
                                $q->bindParam(':lname', $lname, PDO::PARAM_STR);
                                $q->bindParam(':imagename', $imagename, PDO::PARAM_STR);
                                $q->bindParam(':conditional', $conditional, PDO::PARAM_STR);
                                $q->execute();


    $sql1 = "UPDATE people SET firstname = (SELECT firstname FROM user WHERE username=:user_id1) WHERE username=:user_id2";
                                $q = $conn->prepare($sql1) or die("failed!");
                                $q->bindParam(':user_id1', $user_id, PDO::PARAM_STR);
                                $q->bindParam(':user_id2', $user_id, PDO::PARAM_STR);
                                $q->execute();


    $sql2 = "UPDATE people SET surname = (SELECT surname FROM user WHERE username=:user_id1) WHERE username=:user_id2";
                                $q = $conn->prepare($sql2) or die("failed!");
                                $q->bindParam(':user_id1', $user_id, PDO::PARAM_STR);
                                $q->bindParam(':user_id2', $user_id, PDO::PARAM_STR);
                                $q->execute();


    header("Location: success.php");
    exit;
}
else
{
    // A common cause of file moving failures is because of bad permissions on the directory attempting to be written to
    // Make sure you chmod the directory to be writeable
    $_SESSION['error'] = "Could not upload file.  Check read/write permissions on the directory";
    header("Location: securedpage1.php");
    exit;
}
?>

推荐答案

试试这个代码可能对你有帮助

Try this code this may help you

在这个变量中$resizeObj = new resize('sample.png');你需要链接你上传的图片url

in this variable $resizeObj = new resize('sample.png'); you need to link your uploaded picture url

Imagerezise.php

<?php

    // *** Include the class
    include("resize-class.php");

    // *** 1) Initialise / load image
    $resizeObj = new resize('sample.png');

    // *** 2) Resize image (options: exact, portrait, landscape, auto, crop)
    $resizeObj -> resizeImage(200, 200, 'crop');

    // *** 3) Save image
    $resizeObj -> saveImage('sample-resizeda.jpg', 1000);

?>

resize-class.php

<?php

   # ========================================================================#
   #  Requires : Requires PHP5, GD library.
   #  Usage Example:
   #                     include("resize_class.php");
   #                     $resizeObj = new resize('images/cars/large/input.jpg');
   #                     $resizeObj -> resizeImage(150, 100, 0);
   #                     $resizeObj -> saveImage('images/cars/large/output.jpg', 100);
   # ========================================================================#


        class resize
        {
            // *** Class variables
            private $image;
            private $width;
            private $height;
            private $imageResized;

            function __construct($fileName)
            {
                // *** Open up the file
                $this->image = $this->openImage($fileName);

                // *** Get width and height
                $this->width  = imagesx($this->image);
                $this->height = imagesy($this->image);
            }

            ## --------------------------------------------------------

            private function openImage($file)
            {
                // *** Get extension
                $extension = strtolower(strrchr($file, '.'));

                switch($extension)
                {
                    case '.jpg':
                    case '.jpeg':
                        $img = @imagecreatefromjpeg($file);
                        break;
                    case '.gif':
                        $img = @imagecreatefromgif($file);
                        break;
                    case '.png':
                        $img = @imagecreatefrompng($file);
                        break;
                    default:
                        $img = false;
                        break;
                }
                return $img;
            }

            ## --------------------------------------------------------

            public function resizeImage($newWidth, $newHeight, $option="auto")
            {
                // *** Get optimal width and height - based on $option
                $optionArray = $this->getDimensions($newWidth, $newHeight, $option);

                $optimalWidth  = $optionArray['optimalWidth'];
                $optimalHeight = $optionArray['optimalHeight'];


                // *** Resample - create image canvas of x, y size
                $this->imageResized = imagecreatetruecolor($optimalWidth, $optimalHeight);
                imagecopyresampled($this->imageResized, $this->image, 0, 0, 0, 0, $optimalWidth, $optimalHeight, $this->width, $this->height);


                // *** if option is 'crop', then crop too
                if ($option == 'crop') {
                    $this->crop($optimalWidth, $optimalHeight, $newWidth, $newHeight);
                }
            }

            ## --------------------------------------------------------

            private function getDimensions($newWidth, $newHeight, $option)
            {

               switch ($option)
                {
                    case 'exact':
                        $optimalWidth = $newWidth;
                        $optimalHeight= $newHeight;
                        break;
                    case 'portrait':
                        $optimalWidth = $this->getSizeByFixedHeight($newHeight);
                        $optimalHeight= $newHeight;
                        break;
                    case 'landscape':
                        $optimalWidth = $newWidth;
                        $optimalHeight= $this->getSizeByFixedWidth($newWidth);
                        break;
                    case 'auto':
                        $optionArray = $this->getSizeByAuto($newWidth, $newHeight);
                        $optimalWidth = $optionArray['optimalWidth'];
                        $optimalHeight = $optionArray['optimalHeight'];
                        break;
                    case 'crop':
                        $optionArray = $this->getOptimalCrop($newWidth, $newHeight);
                        $optimalWidth = $optionArray['optimalWidth'];
                        $optimalHeight = $optionArray['optimalHeight'];
                        break;
                }
                return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
            }

            ## --------------------------------------------------------

            private function getSizeByFixedHeight($newHeight)
            {
                $ratio = $this->width / $this->height;
                $newWidth = $newHeight * $ratio;
                return $newWidth;
            }

            private function getSizeByFixedWidth($newWidth)
            {
                $ratio = $this->height / $this->width;
                $newHeight = $newWidth * $ratio;
                return $newHeight;
            }

            private function getSizeByAuto($newWidth, $newHeight)
            {
                if ($this->height < $this->width)
                // *** Image to be resized is wider (landscape)
                {
                    $optimalWidth = $newWidth;
                    $optimalHeight= $this->getSizeByFixedWidth($newWidth);
                }
                elseif ($this->height > $this->width)
                // *** Image to be resized is taller (portrait)
                {
                    $optimalWidth = $this->getSizeByFixedHeight($newHeight);
                    $optimalHeight= $newHeight;
                }
                else
                // *** Image to be resizerd is a square
                {
                    if ($newHeight < $newWidth) {
                        $optimalWidth = $newWidth;
                        $optimalHeight= $this->getSizeByFixedWidth($newWidth);
                    } else if ($newHeight > $newWidth) {
                        $optimalWidth = $this->getSizeByFixedHeight($newHeight);
                        $optimalHeight= $newHeight;
                    } else {
                        // *** Sqaure being resized to a square
                        $optimalWidth = $newWidth;
                        $optimalHeight= $newHeight;
                    }
                }

                return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
            }

            ## --------------------------------------------------------

            private function getOptimalCrop($newWidth, $newHeight)
            {

                $heightRatio = $this->height / $newHeight;
                $widthRatio  = $this->width /  $newWidth;

                if ($heightRatio < $widthRatio) {
                    $optimalRatio = $heightRatio;
                } else {
                    $optimalRatio = $widthRatio;
                }

                $optimalHeight = $this->height / $optimalRatio;
                $optimalWidth  = $this->width  / $optimalRatio;

                return array('optimalWidth' => $optimalWidth, 'optimalHeight' => $optimalHeight);
            }

            ## --------------------------------------------------------

            private function crop($optimalWidth, $optimalHeight, $newWidth, $newHeight)
            {
                // *** Find center - this will be used for the crop
                $cropStartX = ( $optimalWidth / 2) - ( $newWidth /2 );
                $cropStartY = ( $optimalHeight/ 2) - ( $newHeight/2 );

                $crop = $this->imageResized;
                //imagedestroy($this->imageResized);

                // *** Now crop from center to exact requested size
                $this->imageResized = imagecreatetruecolor($newWidth , $newHeight);
                imagecopyresampled($this->imageResized, $crop , 0, 0, $cropStartX, $cropStartY, $newWidth, $newHeight , $newWidth, $newHeight);
            }

            ## --------------------------------------------------------

            public function saveImage($savePath, $imageQuality="100")
            {
                // *** Get extension
                $extension = strrchr($savePath, '.');
                   $extension = strtolower($extension);

                switch($extension)
                {
                    case '.jpg':
                    case '.jpeg':
                        if (imagetypes() & IMG_JPG) {
                            imagejpeg($this->imageResized, $savePath, $imageQuality);
                        }
                        break;

                    case '.gif':
                        if (imagetypes() & IMG_GIF) {
                            imagegif($this->imageResized, $savePath);
                        }
                        break;

                    case '.png':
                        // *** Scale quality from 0-100 to 0-9
                        $scaleQuality = round(($imageQuality/100) * 9);

                        // *** Invert quality setting as 0 is best, not 9
                        $invertScaleQuality = 9 - $scaleQuality;

                        if (imagetypes() & IMG_PNG) {
                             imagepng($this->imageResized, $savePath, $invertScaleQuality);
                        }
                        break;

                    // ... etc

                    default:
                        // *** No extension - No save.
                        break;
                }

                imagedestroy($this->imageResized);
            }


            ## --------------------------------------------------------

        }
?>

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