imagesx() from GD library doesnt work in class, but separately works

Question

I have small problem. I need to store some images from news posts and for it I use small resize class from this post: Resizing the image in php for viewing purposes only.

<?php
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);
    }


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

}
?>

But it doesnt work for me and I dont know why.

A tried it separately like this, in loop.

for($i = 1; $i <= $imagesCount; $i++){
    $img = @imagecreatefromjpeg($_FILES["files"]["tmp_name"][$i-1]);
    $imgWidth = imagesx($img);
    echo(json_encode($imgWidth));
}

This outputs for example width 1903 (px).

And when I use library, like this:

for($i = 1; $i <= $imagesCount; $i++){
    $uploadImage = new resize($_FILES["files"]["tmp_name"][$i-1]);
    //$uploadImage -> resizeImage(1920, 1080, 'landscape');
    //$uploadImage -> saveImage("news/" . $newsID["newsID"] . "/full/" . $i . ".jpg", 100);
}

imagesx() throw an error

"imagesx() expects parameter 1 to be resource, bool given in..."

Same error is from imagesy().

I am including this class with autoloader, but there isnt any problem, i think. Does someone know, whats wrong here?

Sorry, but I do not see where you have used `imagesx()` in the code you say is in a library. I am guessing you have not shown us enough code to be able to see the call OR the error — RiggsFolly, Sep 07 '20 at 15:04
In first loop I have showen it is on second line - $imgWidth = imagesx($img); — Tomáš Kretek, Sep 07 '20 at 15:07
Is that first piece of code in the function `resize()` if so, show us all of it — RiggsFolly, Sep 07 '20 at 15:09
Is it happening when `$img = false;` gets returned? Because you never actually check the validity of `$this->image` before using it — RiggsFolly, Sep 07 '20 at 15:22
I figured the file extension was the problem. The server-side file has a .tmp extension. But how do I do it so that php can work with the given image on the server side? — Tomáš Kretek, Sep 09 '20 at 12:13

score 1 · Accepted Answer · answered Sep 09 '20 at 12:42

So I made it finally like this:

edited class:

function __construct($fileName, $extension)
            {
                // *** Open up the file
                $this->image = $this->openImage($fileName, $extension);
                echo(json_encode($this->image));
                // *** Get width and height
                $this->width  = imagesx($this->image);
                $this->height = imagesy($this->image);
            }

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

            private function openImage($file, $extension)
            {

                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;
            }

Edited calling:

for($i = 1; $i <= $imagesCount; $i++){
    $file = $_FILES["files"]["tmp_name"][$i-1];
    $extension = strtolower(strrchr($_FILES["files"]["name"][$i-1], '.'));

    $uploadImage = new resize($file, $extension);
}

So now I can create new object in class with correct file name on server-side and correct extension from client-side. Perhaps it will help someone else.

imagesx() from GD library doesnt work in class, but separately works

1 Answers1