创建用于显示的缩略图或加载 50% 的图像并创建图像预览


Create thumbnail for display OR Load 50% of image and create image preview

正在上传多个文件,单个输入并使用下面给出的代码进行处理如何创建拇指表单图像或加载图像 50% 并创建低质量的图像

    <?php
$newname = md5(rand() * time());
$file1 = isset($_FILES['files']['name'][0]) ? $_FILES['files']['name'][0] : null;
$file2 = isset($_FILES['files']['name'][1]) ? $_FILES['files']['name'][1] : null;
$file3 = isset($_FILES['files']['name'][2]) ? $_FILES['files']['name'][2] : null;
$file4 = isset($_FILES['files']['name'][3]) ? $_FILES['files']['name'][3] : null;
$file5 = isset($_FILES['files']['name'][4]) ? $_FILES['files']['name'][4] : null;
if (isset($_FILES['files'])) {
    $errors = array();
    foreach ($_FILES['files']['tmp_name'] as $key => $tmp_name) {
        $file_name = $key . $_FILES['files']['name'][$key];
        $file_size = $_FILES['files']['size'][$key];
        $file_tmp = $_FILES['files']['tmp_name'][$key];
        $file_type = $_FILES['files']['type'][$key];
        if ($file_size > 2097152) {
            $errors[] = 'File size must be less than 2 MB';
        }
        $desired_dir = "user_data";
        if (empty($errors) == true) {
            if (is_dir($desired_dir) == false) {
                mkdir("$desired_dir", 0700);        // Create directory if it does not exist
            }
            if (is_dir("$desired_dir/" . $file_name) == false) {
                move_uploaded_file($file_tmp, "$desired_dir/" . $newname . $file_name);
            } else {                                  // rename the file if another one exist
                $new_dir = "$desired_dir/" . $newname . $file_name;
                rename($file_tmp, $new_dir);
            }
        } else {
            print_r($errors);
        }
    }
    if (empty($error)) {
        echo "FILE : $file1<br>";
        echo "FILE : $file2<br>";
        echo "FILE : $file3<br>";
        echo "FILE : $file4<br>";
        echo "FILE : $file5<br>";
    }
}
?>

如果上传的图像尺寸为 512 kb,则预览图像应加载较少的原始文件大小以进行预览

使用以下代码创建拇指甲图像,可以创建所有类型的图像文件jpeg, png, gif

    $orig_directory = "$desired_dir";    //Full image folder
    $thumb_directory = "thumb/";    //Thumbnail folder
    /* Opening the thumbnail directory and looping through all the thumbs: */
    $dir_handle = @opendir($orig_directory); //Open Full image dirrectory
    if ($dir_handle > 1) { //Check to make sure the folder opened
        $allowed_types = array('jpg', 'jpeg', 'gif', 'png');
        $file_type = array();
        $ext = '';
        $title = '';
        $i = 0;
        while ($file_name = @readdir($dir_handle)) {
            /* Skipping the system files: */
            if ($file_name == '.' || $file_name == '..')
                continue;
            $file_type = explode('.', $file_name);    //This gets the file name of the images
            $ext = strtolower(array_pop($file_type));
            /* Using the file name (withouth the extension) as a image title: */
            $title = implode('.', $file_type);
            $title = htmlspecialchars($title);
            /* If the file extension is allowed: */
            if (in_array($ext, $allowed_types)) {
                /* If you would like to inpute images into a database, do your mysql query here */
                /* The code past here is the code at the start of the tutorial */
                /* Outputting each image: */
                $nw = 100;
                $nh = 100;
                $source = "$desired_dir{$file_name}";
                $stype = explode(".", $source);
                $stype = $stype[count($stype) - 1];
                $dest = "thumb/{$file_name}";
                $size = getimagesize($source);
                $w = $size[0];
                $h = $size[1];
                switch ($stype) {
                    case 'gif':
                        $simg = imagecreatefromgif($source);
                        break;
                    case 'jpg':
                        $simg = imagecreatefromjpeg($source);
                        break;
                    case 'png':
                        $simg = imagecreatefrompng($source);
                        break;
                }
                $dimg = resizePreservingAspectRatio($simg, $nw, $nh);
                imagepng($dimg, $dest);
            }
        }
        /* Closing the directory */
        @closedir($dir_handle);
    }
}
function resizePreservingAspectRatio($img, $targetWidth, $targetHeight) {
    $srcWidth = imagesx($img);
    $srcHeight = imagesy($img);
    // Determine new width / height preserving aspect ratio
    $srcRatio = $srcWidth / $srcHeight;
    $targetRatio = $targetWidth / $targetHeight;
    if (($srcWidth <= $targetWidth) && ($srcHeight <= $targetHeight)) {
        $imgTargetWidth = $srcWidth;
        $imgTargetHeight = $srcHeight;
    } else if ($targetRatio > $srcRatio) {
        $imgTargetWidth = (int) ($targetHeight * $srcRatio);
        $imgTargetHeight = $targetHeight;
    } else {
        $imgTargetWidth = $targetWidth;
        $imgTargetHeight = (int) ($targetWidth / $srcRatio);
    }
    // Creating new image with desired size
    $targetImg = imagecreatetruecolor($targetWidth, $targetHeight);
    // Add transparency if your reduced image does not fit with the new size
    $targetTransparent = imagecolorallocate($targetImg, 255, 0, 255);
    imagefill($targetImg, 0, 0, $targetTransparent);
    imagecolortransparent($targetImg, $targetTransparent);
    // Copies image, centered to the new one (if it does not fit to it)
    imagecopyresampled($targetImg, $img, 0, 0, 0, 0, $targetWidth, $targetHeight, $srcWidth, $srcHeight);
    return $targetImg;
}
?>