imagecreatefromjpeg
(PHP 4, PHP 5)
imagecreatefromjpeg — Create a new image from file or URL
說明
imagecreatefromjpeg() returns an image identifier representing the image obtained from the given filename.
On failure imagecreatefromjpeg() outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error JPEG:
Example#1 Example to handle an error during creation
<?php
function LoadJpeg($imgname)
{
$im = @imagecreatefromjpeg($imgname); /* Attempt to open */
if (!$im) { /* See if it failed */
$im = imagecreatetruecolor(150, 30); /* Create a black image */
$bgc = imagecolorallocate($im, 255, 255, 255);
$tc = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 150, 30, $bgc);
/* Output an errmsg */
imagestring($im, 1, 5, 5, "Error loading $imgname", $tc);
}
return $im;
}
header("Content-Type: image/jpeg");
$img = LoadJpeg("bogus.image");
imagejpeg($img);
?>
上例的輸出類似於:

如果「fopen wrappers」已經被啟用,則在本函式中可以把 URL 作為檔案名來使用。請參閱 fopen() 函式來獲取如何指定文件名的詳情以及支援 URL 協定列表:List of Supported Protocols/Wrappers。
參數
- filename
-
Path to the JPEG image
Return值
Returns an image resource identifier on success, FALSE on errors.
註釋
Note: JPEG 支持僅在 PHP 與 GD-1.8 或更高版本一起編譯時可用。
PHP 4.3.0 之前的 Windows PHP版本,即使啟動allow_url_fopen選項,也不支援由此函式存取遠端檔案。