how to create multiple thumbnails while uploading image without libraries?

问题

I am trying to create multiple images while uploading,

I found a solution from This site this is exactly what I want.

But sadly it only creating jpeg thumbnails.

I have tried many variations to turn function for multiple image extention but keep geting errors.

I realy need help.

This main function which is uploading image it call createThumbnails() from functions file:

require_once('function.php');


if(isset($_POST['btnSubmit']) && isset($_FILES['fupload'])) {
    $output['status'] = FALSE;
    set_time_limit(0);
    $allowedImageType = array("image/gif",   "image/jpeg",   "image/pjpeg",   "image/png",   "image/x-png"  );

    if ($_FILES['fupload']["error"] > 0) {
        $output['error']= "File Error";
    }
    elseif (!in_array($_FILES['fupload']["type"], $allowedImageType)) {
        $output['error']= "Invalid image format";
    }
    elseif (round($_FILES['fupload']["size"] / 1024) > 4096) {
        $output['error']= "Maximum file upload size is exceeded";
    } else {
        $temp_path = $_FILES['fupload']['tmp_name'];
        $selam = $_FILES['fupload']['name'];
        $file = pathinfo($_FILES['fupload']['name']);
        $fileType = $file["extension"];
        $fileName = rand(222, 888) . $selam;

        $small_thumbnail_path = "uploads/small/";
        createFolder($small_thumbnail_path);
        $small_thumbnail = $small_thumbnail_path . $fileName;

        $medium_thumbnail_path = "uploads/medium/";
        createFolder($medium_thumbnail_path);
        $medium_thumbnail = $medium_thumbnail_path . $fileName;

        $large_thumbnail_path = "uploads/large/";
        createFolder($large_thumbnail_path);
        $large_thumbnail = $large_thumbnail_path . $fileName;

        $thumb1 = createThumbnail($temp_path, $small_thumbnail,$fileType, 150, 93);
        $thumb2 = createThumbnail($temp_path, $medium_thumbnail, $fileType, 300, 185);
        $thumb3 = createThumbnail($temp_path, $large_thumbnail,$fileType, 550, 340);

        $Name = htmlspecialchars($_POST['sname']);      
        $sql = "INSERT INTO tbl_images(image, sname) VALUES (:image, :sname)";
        $stmt =$pdo->prepare($sql);
        $stmt->bindParam(":image", $large_thumbnail, PDO::PARAM_STR);
        $stmt->bindParam(":sname", $Name, PDO::PARAM_STR);
        if($stmt->execute()){
            echo "All successfully.";
        } else {
            echo "All Not Success.";
        }

        if($thumb1 && $thumb2 && $thumb3) {
            $output['status']=TRUE;
            $output['small']= $small_thumbnail;
            $output['medium']= $medium_thumbnail;
            $output['large']= $large_thumbnail;
        }
    }
    echo json_encode($output);
}

<from action="upload.php">
<input type="file" name="fupload"/>
<button type="submit">submit</button>
</form><from action="upload.php">
<input type="file" name="fupload"/>
<button type="submit">submit</button>
</form>

This is the function creating folders for thumbnails if not exist its working fine:

function createFolder($path)
{       
    if (!file_exists($path)) {
        mkdir($path, 0755, TRUE);
    }
}

This is the original function which is working fine only for jpeg and I want to turn it to support multiple extentions:

function createThumbnail($sourcePath, $targetPath, $file_type, $thumbWidth, $thumbHeight){

    $source = imagecreatefromjpeg($sourcePath);

    $width = imagesx($source);
    $height = imagesy($source);

    $tnumbImage = imagecreatetruecolor($thumbWidth, $thumbHeight);

    imagecopyresampled($tnumbImage, $source, 0, 0, 0, 0, $thumbWidth, $thumbHeight, $width, $height);

    if (imagejpeg($tnumbImage, $targetPath, 90)) {
        imagedestroy($tnumbImage);
        imagedestroy($source);
        return TRUE;
    } else {
        return FALSE;
    }
}

And this is my latest try its resizing and uploading file same as I want, But now I have problem with png background transparent I get png images with black backgorund :

function createFolder($path)
{       
    if (!file_exists($path)) {
        mkdir($path, 0755, TRUE);
    }
}

function createThumbnail($sourcePath, $targetPath, $file_type, $thumbWidth, $thumbHeight){

    switch (strtoupper($file_type)):
    case 'jpg':
    $source = imagecreatefromjpeg($sourcePath);
    break;
    case 'JPG':
    $source = imagecreatefromjpeg($sourcePath);
    break;
    case 'png':
    $source = imagecreatefrompng($sourcePath);
    break;
    case 'PNG':
    $source = imagecreatefrompng($sourcePath);
    break;
    case 'gif':
    $source = imagecreatefromgif($sourcePath);
    break;
    case 'GIF':
    $source = imagecreatefromgif($sourcePath);
    break;
    default:
    echo "Invalid File Type";
    endswitch;

    $width = imagesx($source);
    $height = imagesy($source);

    $tnumbImage = imagecreatetruecolor($thumbWidth, $thumbHeight);

    imagecopyresampled($tnumbImage, $source, 0, 0, 0, 0, $thumbWidth, $thumbHeight, $width, $height);

    if(imagegif($tnumbImage, $targetPath, 80)) {
        imagedestroy($tnumbImage);
        imagedestroy($source);
        return TRUE;
    }if(imagepng($tnumbImage, $targetPath, 80)) {
        imagedestroy($tnumbImage);
        imagedestroy($source);
        return TRUE;
    }if(imagejpeg($tnumbImage, $targetPath, 80)) {
        imagedestroy($tnumbImage);
        imagedestroy($source);
        return TRUE;
    } else {
        return FALSE;
    }
}

But I am having tons of errors and not uploading images thanks to all qho can help.

来源：https://stackoverflow.com/questions/58792156/how-to-create-multiple-thumbnails-while-uploading-image-without-libraries