Php/docs/function.exif-thumbnail

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exif_thumbnail

(PHP 4 >= 4.2.0, PHP 5, PHP 7)

exif_thumbnail取得嵌入在 TIFF 或 JPEG 图像中的缩略图


说明

exif_thumbnail ( string $filename [, int &$width [, int &$height [, int &$imagetype ]]] ) : string

exif_thumbnail() 读取 TIFF 或 JPEG 图像中的嵌入缩略图。如果图像不包含缩略图则返回 false

If you want to deliver thumbnails through this function, you should send the mimetype information using the header() function.

It is possible that exif_thumbnail() cannot create an image but can determine its size. In this case, the return value is false but width and height are set.


参数

filename
The name of the image file being read. This image contains an embedded thumbnail.
width
The return width of the returned thumbnail.
height
The returned height of the returned thumbnail.
imagetype
The returned image type of the returned thumbnail. This is either TIFF or JPEG.


返回值

Returns the embedded thumbnail, or false if the image contains no thumbnail.


更新日志

版本 说明
4.3.0 The optional parameters width,

height, and imagetype all became available.

4.3.0 May return thumbnails in the TIFF format.


范例

Example #1 exif_thumbnail() 例子

<?phpif (array_key_exists('file',$_REQUEST)) {    $image = exif_thumbnail($_REQUEST['file'], $width, $height, $type);} else {    $image = false;}if ($image!==false) {    header("Content-type: ".image_type_to_mime_type($type));    echo $image;    exit;} else {    // no thumbnail available, handle the error here    echo "No thumbnail available";}?>

参见

  • exif_read_data() - 从 JPEG 或 TIFF 文件中读取 EXIF 头信息
  • image_type_to_mime_type() - 取得 getimagesize,exif_read_data,exif_thumbnail,exif_imagetype 所返回的图像类型的 MIME 类型