Question

我最终设法让用户上传的图片保持透明，当它们是png时，通过这样做：

    $image_p = imagecreatetruecolor($fixed_width, $fixed_height);

    if ($_FILES[$fileName]["type"] == "image/x-png" || $_FILES[$fileName]["type"] == "image/png") {

        $background = imagecolorallocate($image_p, 0, 0, 0);
        imagecolortransparent($image_p, $background);
        imagealphablending($image_p, false);
        imagesavealpha($image_p, true);
    }

    // PNG or JPG
    if ($_FILES[$fileName]["type"] == "image/jpeg" || $_FILES[$fileName]["type"] == "image/jpg" || $_FILES[$fileName]["type"] == "image/pjpeg") {
        $image = imagecreatefromjpeg($imageFile);
    } else {
        $image = imagecreatefrompng($imageFile);
    }


    // check if img is bigger then max width
    $manipulated = 0;

    if ($width_orig > $fixed_width) {
        imagecopyresampled($image_p, $image, 0, 0, 0, 0, $fixed_width, $fixed_height, $width_orig, $height_orig); // reduce in width / height
        $manipulated = 1;
    } else {
        $image_p = $image; // leave as is
    }

    // Output PNG or JPG
    if ($_FILES[$fileName]["type"] == "image/jpeg" || $_FILES[$fileName]["type"] == "image/jpg" || $_FILES[$fileName]["type"] == "image/pjpeg") {
        imagejpeg($image_p, $newfile, 65);
    } else {
        imagepng($image_p, $newfile, 6);
    }

但现在我有问题将它们显示为.png，当我从Cpanel字典中打开文件时，它是透明的，但是当我显示它时：

<?php

$file = basename(urldecode($_GET['img']));
$file = str_replace("../", "", $file); 

$fileDir = '/home/funkydic/noaccess/avatars/';

$jpg = strpos($file, '.jpg');
$jpeg = strpos($file, '.jpeg');
$png = strpos($file, '.png');

if ($jpg != false || $jpeg != false) {

    if (file_exists($fileDir . $file)) {

        $imageRes = imagecreatefromjpeg($fileDir . $file);
        header('Content-Type: image/jpeg');
        // Output the image
        @imagepng($imageRes);
        // Free up memory
        @imagedestroy($imageRes);
        die();
    }
}
elseif ($png != false) {

    if (file_exists($fileDir . $file)) {


        $imageRes = imagecreatefrompng($fileDir . $file);

        header('Content-Type: image/png');
        // Output the image
        @imagepng($imageRes);
        // Free up memory
        @imagedestroy($imageRes);
        die();
    }
}
?>

黑框在透明区域返回。

Answer 1

如果您已经有一个只想发送到浏览器的PNG，那么就不需要GD了。

header('Content-Type: image/png');
fp = fopen($fileDir . $file, "r");
fpassthru($fp);
fclose($fp); /* this is not necessary, but I prefer to keep it */
exit();

由于您以相同的方式导出JPEG（顺便说一句，您在该部分中有错误：标题显示为image/jpeg，而您发送了带有@imagepng()的PNG），我会重写您的代码像这样：

<?php

$allowedMimes = array("png", "gif", "jpeg");
$fileDir = '/home/funkydic/noaccess/avatars/';

$file = basename(urldecode($_GET['img']));
$file = str_replace("../", "", $file); /* what's this for? you already have basename() */

if (file_exists($fileDir . $file)) {
    $mime = strtolow(pathinfo($file, PATHINFO_EXTENSION));
    if ($mime == "jpg") $mime = "jpeg";

    if (in_array($mime, $allowedMimes)) {
        header("Content-Type: image/$mime");
        fp = fopen($fileDir . $file, "r");
        fpassthru($fp);
        fclose($fp);
        exit();
    }
    /* if you get here, extension in the GET request was wrong */
}
/* if you get here, extension in the GET request was wrong or the file doesn't exist */
?>

显示上传的.PNG图像透明的问题

1 个答案: