exif_thumbnail

(PHP 4 >= 4.2.0, PHP 5)

exif_thumbnail — Retrieve the embedded thumbnail of a TIFF or JPEG image

Описание

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

exif_thumbnail() reads the embedded thumbnail of a TIFF or JPEG image.

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.

Список параметров

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.

Возвращаемые значения

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

Список изменений

Версия Описание
4.3.0 The optional parameters width , height , and imagetype all became available.
4.3.0 May return thumbnails in the TIFF format.

Примеры

Пример #1 exif_thumbnail() example

<?php
if (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';
}
?>

Смотрите также

Коментарии

Автор:
This will allow you to manipulate the thumbnail image ($imgJpeg) using the various gd commands:

<?php
 
if (($imgJpeg exif_thumbnail($strImagePath)) === false)
    print 
"No Thumbnail!";
  else
   
$imgJpeg imageCreateFromString($imgJpeg);
?>
2004-06-13 22:05:33
http://php5.kiev.ua/manual/ru/function.exif-thumbnail.html
Great that the thumbnail can be in TIFF format (f.i. Kodak cameras have embedded thumbnail in TIFF) BUT I have not been able to show TIFF as an embedded image in HTML (using the <IMG...> tag). There seems to be no function in PHP to change TIFF to, lets say, JPG. (imagecreatefromstring gives a 'unknown datatype' error for the TIFF stream. So below sample works great for JPEG embedded thumbnail, but not for TIFF embedded (but then, maybe I did something wrong?):

test_exif.php:

<HTML>
<HEAD>
    <TITLE>Test EXIF Read  </TITLE>
</HEAD>
<BODY>
<?php
$image
='P0000614.JPG';
echo(
"<B>"$image"</B>:<BR><BR>\n");

$exif exif_read_data($image'ANY_TAG',true);
if (!
$exif===false)
{
    echo(
"Image contains headers<br><br>");
    echo(
"<A href=showthumb.php?image=" $image ."> <IMG border=0 src=showthumb.php?image=" $image ."></A><BR><BR>");

    foreach (
$exif as $key => $section
    {
        foreach (
$section as $name => $val
        {
            echo 
"$key.$name$val<br>\n";
        }
    }
}
else
{
    echo(
"Sorry, image <B>".$image "</B> does not contain (readable) EXIF data.");
}
?>
</BODY>
</HTML>

showthumb.php:

<?php
$imgdat 
exif_thumbnail($_REQUEST['image'],$width$height$type);
header('Content-type: ' image_type_to_mime_type($type));
echo(
$imgdat);
?>

When clicking on the <A> opens the TIFF image in the program that windows assigned to this type, but the JPEG opens in the browser.

I am using PHP 4.3.6 on windows iis 4 (yeah, I know.....)
2005-01-14 08:35:30
http://php5.kiev.ua/manual/ru/function.exif-thumbnail.html
Автор:
If you want to convert from TIFF to JPG you can use ImageMagick if it is installed in your server.

<?php
$exec 
'convert /path/to/file.tiff /path/to/file.jpg 2>&1';
@
exec($exec$exec_output$exec_retval);

//possible error
print_r($exec_output)
?>
2007-01-05 08:23:39
http://php5.kiev.ua/manual/ru/function.exif-thumbnail.html
Автор:
use this if you want to embed a thumbnail directly on the HTML page without writing it first to a file:

<?php
$image 
exif_thumbnail($file$width$height$type);

echo 
"<img  width='$width' height='$height' src='data:image/gif;base64,".base64_encode($image)."'>";
?>
2007-10-08 09:37:28
http://php5.kiev.ua/manual/ru/function.exif-thumbnail.html
If you've edited the image with image editing software and it no longer contains an exif thumbnail, I've created a script that will add one back into it, using the "PHP Exif Library": http://pel.sourceforge.net/index.php

<?php
require_once('../PEL/PelJpeg.php');
require_once(
'../PEL/PelIfd.php');
$fullpath 'images/DSC_0013c.JPG'# path of source image (does not contain an exif thumbnail)
     
$jpeg = new PelJpeg($fullpath);
 
$exif $jpeg->getExif();
 
$tiff $exif->getTiff();
 
$ifd0 $tiff->getIfd();        # need this so that we can later link it to the new IFD 

 
$ifd1 $ifd0->getNextIfd();
if (!
$ifd1) {        # Only create thumbnail if one doesn't exist (i.e. there is no IFD1)
   
$ifd1 = new PelIfd(1);
   
$ifd0->setNextIfd($ifd1); # point ifd0 to the new ifd1 (or else ifd1 will not be read)

   
$original ImageCreateFromString($jpeg->getBytes()); # create image resource of original
   
$orig_w=imagesx($original);
   
$orig_h=imagesy($original);
   
$wmax 160;
   
$hmax 120;

    if (
$orig_w>$wmax || $orig_h>$hmax) {
       
$thumb_w=$wmax;
       
$thumb_h=$hmax;
        if (
$thumb_w/$orig_w*$orig_h>$thumb_h)
           
$thumb_w=round($thumb_h*$orig_w/$orig_h); # maintain aspect ratio
       
else
           
$thumb_h=round($thumb_w*$orig_h/$orig_w);
    }
    else { 
# only set the thumb's size if the original is larger than 'wmax'x'hmax'
       
$thumb_w=$orig_w;
       
$thumb_h=$orig_h;
    }

       
# create image resource with thumbnail sizing
   
$thumb=imagecreatetruecolor($thumb_w,$thumb_h); 
       
## Resize original and copy to the blank thumb resource
   
imagecopyresampled($thumb,$original,
                               
0,0,0,0,$thumb_w,$thumb_h,$orig_w,$orig_h);

       
# start writing output to buffer
   
ob_start();       
       
# outputs thumb resource contents to buffer
   
ImageJpeg($thumb);   
       
# create PelDataWindow from buffer thumb contents (and end output to buffer)
   
$window = new PelDataWindow(ob_get_clean()); 

    if (
$window) {   

       
$ifd1->setThumbnail($window); # set window data as thumbnail in ifd1
       
$outpath $fullpath# overwrite original jpg file
       
file_put_contents($outpath$jpeg->getBytes()); # write everything to output filename
            # Show thumbnail in file:
       
echo '<img src="thumb_exif.php?image='.$outpath.'" border=0 alt="If you see this, it did not work"><br>';

       
    }
}
else {
    echo 
'ifd1 already exists! (IFD1 is where the thumbnail is stored)<br>';
}
?>
<?php 
# This is the code in thumb_exif.php :
       
$imgdat exif_thumbnail($_REQUEST['image'], $width$height$type);
       
header('Content-type: ' image_type_to_mime_type($type));
        echo(
$imgdat);
?>

If you have a lot of such files, you can easily make a script that searches them out and adds thumbnails to their exif.
2008-07-29 16:40:59
http://php5.kiev.ua/manual/ru/function.exif-thumbnail.html

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