exif_thumbnail

(PHP 4 >= 4.2.0, PHP 5)

exif_thumbnailRecupera a miniatura embutida de uma imagem TIFF ou JPEG

Descrição

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

exif_thumbnail() lê a miniatura embutida de uma imagem TIFF ou JPEG.

Se você quer exibir miniaturas através desta função, você pode enviar a informação do mimetype usando a função header().

É possível que exif_thumbnail() não crie uma imagem mas pode terminar o tamanho. Neste caso, o valor retornado é FALSE mas width e height são definidos.

Parâmetros

filename

O nome do arquivo da imagem a ser lido. Esta imagem contém uma miniatura embutida.

width

A largura da miniatura retornada.

height

A altura da miniatura retornada.

imagetype

O tipo da imagem da miniatura retornada. Pode ser TIFF ou JPEG.

Valor Retornado

Retorna a miniatura embutida, our FALSE se a imagem não contém miniatura.

Changelog

Versão Descrição
4.3.0 O parâmetro opcional width, height, e imagetype tornaram-se disponíveis.
4.3.0 Pode retornar miniatura no formato TIFF.

Exemplos

Exemplo #1 Exemplo da exif_thumbnail()

<?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';
}
?>

Veja Também

  • exif_read_data() - Lê os cabeçalhos EXIF de imagens JPEG ou TIFF. Deste modo você poderá ler meta dados gerados por camêras digitais.
  • image_type_to_mime_type() - Obtém o Mime-Type para um tipo de imagem retornado por getimagesize, exif_read_data, exif_thumbnail, exif_imagetype

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User Contributed Notes 5 notes

up
1
Eric
10 years ago
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);
?>
up
0
thrustvector at &#39;gee&#39;mail dot com
5 years ago
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.
up
0
Miguel Vitorino
6 years ago
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)."'>";
?>
up
0
Anonymous
7 years ago
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)
?>
up
0
hanspeter dot debets at dendrite dot com
9 years ago
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.....)
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