PHP 5.4.33 Released

exif_read_data

(PHP 4 >= 4.2.0, PHP 5)

exif_read_dataReads the EXIF headers from JPEG or TIFF

Descrizione

array exif_read_data ( string $filename [, string $sections = NULL [, bool $arrays = false [, bool $thumbnail = false ]]] )

exif_read_data() reads the EXIF headers from a JPEG or TIFF image file. This way you can read meta data generated by digital cameras.

EXIF headers tend to be present in JPEG/TIFF images generated by digital cameras, but unfortunately each digital camera maker has a different idea of how to actually tag their images, so you can't always rely on a specific Exif header being present.

Height and Width are computed the same way getimagesize() does so their values must not be part of any header returned. Also, html is a height/width text string to be used inside normal HTML.

When an Exif header contains a Copyright note, this itself can contain two values. As the solution is inconsistent in the Exif 2.10 standard, the COMPUTED section will return both entries Copyright.Photographer and Copyright.Editor while the IFD0 sections contains the byte array with the NULL character that splits both entries. Or just the first entry if the datatype was wrong (normal behaviour of Exif). The COMPUTED will also contain the entry Copyright which is either the original copyright string, or a comma separated list of the photo and editor copyright.

The tag UserComment has the same problem as the Copyright tag. It can store two values. First the encoding used, and second the value itself. If so the IFD section only contains the encoding or a byte array. The COMPUTED section will store both in the entries UserCommentEncoding and UserComment. The entry UserComment is available in both cases so it should be used in preference to the value in IFD0 section.

exif_read_data() also validates EXIF data tags according to the EXIF specification (» http://exif.org/Exif2-2.PDF, page 20).

Nota:

Windows Me/XP can both wipe the Exif headers when connecting to a camera.

Elenco dei parametri

filename

The name of the image file being read. This cannot be an URL.

sections

Is a comma separated list of sections that need to be present in file to produce a result array. If none of the requested sections could be found the return value is FALSE.

FILE FileName, FileSize, FileDateTime, SectionsFound
COMPUTED html, Width, Height, IsColor, and more if available. Height and Width are computed the same way getimagesize() does so their values must not be part of any header returned. Also, html is a height/width text string to be used inside normal HTML.
ANY_TAG Any information that has a Tag e.g. IFD0, EXIF, ...
IFD0 All tagged data of IFD0. In normal imagefiles this contains image size and so forth.
THUMBNAIL A file is supposed to contain a thumbnail if it has a second IFD. All tagged information about the embedded thumbnail is stored in this section.
COMMENT Comment headers of JPEG images.
EXIF The EXIF section is a sub section of IFD0. It contains more detailed information about an image. Most of these entries are digital camera related.

arrays

Specifies whether or not each section becomes an array. The sections COMPUTED, THUMBNAIL, and COMMENT always become arrays as they may contain values whose names conflict with other sections.

thumbnail

When set to TRUE the thumbnail itself is read. Otherwise, only the tagged data is read.

Valori restituiti

It returns an associative array where the array indexes are the header names and the array values are the values associated with those headers. If no data can be returned, exif_read_data() will return FALSE.

Log delle modifiche

Versione Descrizione
4.3.0 Can read all embedded IFD data including arrays (returned as such). Also the size of an embedded thumbnail is returned in a THUMBNAIL subarray, and can return thumbnails in TIFF format. Also, there is no longer a maximum length for returned values (not until the memory limit has been reached)
4.3.0 If PHP has mbstring support, the user comment can automatically change encoding. Also, if the user comment uses Unicode or JIS encoding this encoding will automatically be changed according to the exif ini settings in php.ini
4.3.0 If the image contains any IFD0 data then COMPUTED contains the entry ByteOrderMotorola which is 0 for little-endian (intel) and 1 for big-endian (motorola) byte order. Also, COMPUTED and UserComment no longer only contain the first copyright entry if the datatype was wrong.

Esempi

Example #1 exif_read_data() example

<?php
echo "test1.jpg:<br />\n";
$exif exif_read_data('tests/test1.jpg''IFD0');
echo 
$exif===false "No header data found.<br />\n" "Image contains headers<br />\n";

$exif exif_read_data('tests/test2.jpg'0true);
echo 
"test2.jpg:<br />\n";
foreach (
$exif as $key => $section) {
    foreach (
$section as $name => $val) {
        echo 
"$key.$name$val<br />\n";
    }
}
?>

The first call fails because the image has no header information.

Il precedente esempio visualizzerà qualcosa simile a:

test1.jpg:
No header data found.
test2.jpg:
FILE.FileName: test2.jpg
FILE.FileDateTime: 1017666176
FILE.FileSize: 1240
FILE.FileType: 2
FILE.SectionsFound: ANY_TAG, IFD0, THUMBNAIL, COMMENT
COMPUTED.html: width="1" height="1"
COMPUTED.Height: 1
COMPUTED.Width: 1
COMPUTED.IsColor: 1
COMPUTED.ByteOrderMotorola: 1
COMPUTED.UserComment: Exif test image.
COMPUTED.UserCommentEncoding: ASCII
COMPUTED.Copyright: Photo (c) M.Boerger, Edited by M.Boerger.
COMPUTED.Copyright.Photographer: Photo (c) M.Boerger
COMPUTED.Copyright.Editor: Edited by M.Boerger.
IFD0.Copyright: Photo (c) M.Boerger
IFD0.UserComment: ASCII
THUMBNAIL.JPEGInterchangeFormat: 134
THUMBNAIL.JPEGInterchangeFormatLength: 523
COMMENT.0: Comment #1.
COMMENT.1: Comment #2.
COMMENT.2: Comment #3end
THUMBNAIL.JPEGInterchangeFormat: 134
THUMBNAIL.Thumbnail.Height: 1
THUMBNAIL.Thumbnail.Height: 1

Vedere anche:

add a note add a note

User Contributed Notes 16 notes

up
13
chadsmith729 at gmail dot com
1 year ago
When the new update came out from Apple for iOS6 it provided the ability for iPad, iPod, and iPhones to be able to upload files from the device through Safari. Obviously this will open up an array of implementations where at one point it was just not possible.

The issue comes when a photo is uploaded it will be dependent on the location of the "button" when the photo was taken. Imagine if you will that you have your iPhone turned with the button at the top and you take a photo. The photo when uploaded to your server might be "upside down".

The following code will ensure that all uploaded photos will be oriented correctly upon upload:
<?php
$image
= imagecreatefromstring(file_get_contents($_FILES['image_upload']['tmp_name']));
$exif = exif_read_data($_FILES['image_upload']['tmp_name']);
if(!empty(
$exif['Orientation'])) {
    switch(
$exif['Orientation']) {
        case
8:
           
$image = imagerotate($image,90,0);
            break;
        case
3:
           
$image = imagerotate($image,180,0);
            break;
        case
6:
           
$image = imagerotate($image,-90,0);
            break;
    }
}
// $image now contains a resource with the image oriented correctly
?>

What you do with the image resource from there is entirely up to you.

I hope that this helps you identify and orient any image that's uploaded from an iPad, iPhone, or iPod. Orientation for the photo is the key to knowing how to rotate it correctly.
up
3
darkain at darkain dot com
6 years ago
I wanted some quick and easy functions for computing the shutter speed and f-stop.  I couldn't find any anywhere, so I made some.  It took some research :

<?php
function exif_get_float($value) {
 
$pos = strpos($value, '/');
  if (
$pos === false) return (float) $value;
 
$a = (float) substr($value, 0, $pos);
 
$b = (float) substr($value, $pos+1);
  return (
$b == 0) ? ($a) : ($a / $b);
}

function
exif_get_shutter(&$exif) {
  if (!isset(
$exif['ShutterSpeedValue'])) return false;
 
$apex    = exif_get_float($exif['ShutterSpeedValue']);
 
$shutter = pow(2, -$apex);
  if (
$shutter == 0) return false;
  if (
$shutter >= 1) return round($shutter) . 's';
  return
'1/' . round(1 / $shutter) . 's';
}

function
exif_get_fstop(&$exif) {
  if (!isset(
$exif['ApertureValue'])) return false;
 
$apex  = exif_get_float($exif['ApertureValue']);
 
$fstop = pow(2, $apex/2);
  if (
$fstop == 0) return false;
  return
'f/' . round($fstop,1);
}
?>
up
3
lincolnzsilva at gmail dot com
5 years ago
Get some EXIFs fields (easy way):

<?php
        $exif_make
= exif_read_data ( $_FILES['photo']['tmp_name'] ,'IFD0' ,0 );
       
$emake = $exif_make['Make'];
       
       
$exif_model = exif_read_data ( $_FILES['photo']['tmp_name'] ,'IFD0' ,0 );
       
$emodel = $exif_model['Model'];
       
       
$exif_exposuretime = exif_read_data ( $_FILES['photo']['tmp_name'] ,'EXIF' ,0 );
       
$eexposuretime = $exif_exposuretime['ExposureTime'];
       
       
$exif_fnumber = exif_read_data ( $_FILES['photo']['tmp_name'] ,'EXIF' ,0 );
       
$efnumber = $exif_fnumber['FNumber'];

       
$exif_iso = exif_read_data ( $_FILES['photo']['tmp_name'] ,'EXIF' ,0 );
       
$eiso = $exif_iso['ISOSpeedRatings'];
               
       
$exif_date = exif_read_data ( $_FILES['photo']['tmp_name'] ,'IFD0' ,0 );
       
$edate = $exif_date['DateTime'];
?>
up
1
michael [at[ thisiswilson [dot[ com
5 years ago
From - darkain at darkain dot com 's example.

If all the data is from the same image - simply

<?php
        $exif_data
= exif_read_data ( $_FILES['photo']

       
$emake =$exif_data['Make'];
       
$emodel = $exif_data['Model'];
       
$eexposuretime = $exif_data['ExposureTime'];
       
$efnumber = $exif_data['FNumber'];
       
$eiso = $exif_data['ISOSpeedRatings'];
       
$edate = $exif_data['DateTime'];
?>

will work, I tried using the PEL library, and while pretty cool, I can't for the life understand how to call some things, this is simpler if your system is pretty basic or if you're in a rush.  If you have time, try playing with PEL.  It's not maintained at the moment though..

http://pel.sourceforge.net/
up
1
iam at thatguy dot co dot za
9 months ago
I posted the original version of the function, but after using it for a while I discovered I didn't do enough error checking.

I have re-factored it somewhat, and it now returns an empty array should it not be able to read the image's exif. If it is able to, it will return the details it was able to retrieve. And this should be without error.

I am suppressing errors, because if you pass it images which cannot parse, you will get a warning.

<?php

# Modified Version of cameraUsed, no longer returns date.
public function cameraUsed($imagePath)
{
   
# The default empty return
   
$return = array(
       
'make'      => "",
       
'model'     => "",
       
'exposure'  => "",
       
'aperture'  => "",
       
'iso'       => ""
   
);

   
// Check if the variable is set and if the file itself exists before continuing
   
if ((isset($imagePath)) AND (file_exists($imagePath)))
    {
       
// There are 2 arrays which contains the information we are after, so it's easier to state them both
       
$exif_ifd0 = @read_exif_data($imagePath ,'IFD0' ,0);
       
$exif_exif = @read_exif_data($imagePath ,'EXIF' ,0);

       
# Ensure that we actually got some information
       
if (($exif_ifd0 !== false) AND ($exif_exif !== false))
        {
           
// Make
           
if (@array_key_exists('Make', $exif_ifd0))
            {
               
$return['make']     = $exif_ifd0['Make'];
            }

           
// Model
           
if (@array_key_exists('Model', $exif_ifd0))
            {
               
$return['model']    = $exif_ifd0['Model'];
            }

           
// Exposure
           
if (@array_key_exists('ExposureTime', $exif_ifd0))
            {
               
$return['exposure'] = $exif_ifd0['ExposureTime'];
            }

           
// Aperture
           
if (@array_key_exists('ApertureFNumber', $exif_ifd0['COMPUTED']))
            {
               
$return['aperture'] = $exif_ifd0['COMPUTED']['ApertureFNumber'];
            }

           
// ISO
           
if (@array_key_exists('ISOSpeedRatings',$exif_exif))
            {
               
$return['iso']     = $exif_exif['ISOSpeedRatings'];
            }
        }
    }

   
# Return either an empty array, or the details which we were able to extrapolate.
   
return $return;
}

?>
up
0
Shiva
11 days ago
Hi all,

I used this function for reading exif data from images. Turns out that if some metadata fields are empty then the function reports unidentified tags with garbage data.

Hope this helps someone.
up
0
drpain at webster dot org dot za
2 years ago
Please note that when resizing images with GD and most image processing scripts or applications you will loose the EXIF information. What I did as a workaround is book this information into MySQL before I re-size images.

<?php

// This function is used to determine the camera details for a specific image. It returns an array with the parameters.
function cameraUsed($imagePath) {

   
// Check if the variable is set and if the file itself exists before continuing
   
if ((isset($imagePath)) and (file_exists($imagePath))) {
   
     
// There are 2 arrays which contains the information we are after, so it's easier to state them both
     
$exif_ifd0 = read_exif_data($imagePath ,'IFD0' ,0);      
     
$exif_exif = read_exif_data($imagePath ,'EXIF' ,0);
     
     
//error control
     
$notFound = "Unavailable";
     
     
// Make
     
if (@array_key_exists('Make', $exif_ifd0)) {
       
$camMake = $exif_ifd0['Make'];
      } else {
$camMake = $notFound; }
     
     
// Model
     
if (@array_key_exists('Model', $exif_ifd0)) {
       
$camModel = $exif_ifd0['Model'];
      } else {
$camModel = $notFound; }
     
     
// Exposure
     
if (@array_key_exists('ExposureTime', $exif_ifd0)) {
       
$camExposure = $exif_ifd0['ExposureTime'];
      } else {
$camExposure = $notFound; }

     
// Aperture
     
if (@array_key_exists('ApertureFNumber', $exif_ifd0['COMPUTED'])) {
       
$camAperture = $exif_ifd0['COMPUTED']['ApertureFNumber'];
      } else {
$camAperture = $notFound; }
     
     
// Date
     
if (@array_key_exists('DateTime', $exif_ifd0)) {
       
$camDate = $exif_ifd0['DateTime'];
      } else {
$camDate = $notFound; }
     
     
// ISO
     
if (@array_key_exists('ISOSpeedRatings',$exif_exif)) {
       
$camIso = $exif_exif['ISOSpeedRatings'];
      } else {
$camIso = $notFound; }
     
     
$return = array();
     
$return['make'] = $camMake;
     
$return['model'] = $camModel;
     
$return['exposure'] = $camExposure;
     
$return['aperture'] = $camAperture;
     
$return['date'] = $camDate;
     
$return['iso'] = $camIso;
      return
$return;
   
    } else {
      return
false;
    }
}

?>

An example of it's use follows:

<?php

$camera
= cameraUsed("/img/myphoto.jpg");
echo
"Camera Used: " . $camera['make'] . " " . $camera['model'] . "<br />";
echo
"Exposure Time: " . $camera['exposure'] . "<br />";
echo
"Aperture: " . $camera['aperture'] . "<br />";
echo
"ISO: " . $camera['iso'] . "<br />";
echo
"Date Taken: " . $camera['date'] . "<br />";

?>

Will display the following, depending on the data:

Camera Used: SONY DSC-S930
Exposure Time: 1/400
Aperture: f/4.3
ISO: 100
Date Taken: 2010:12:10 18:18:45

If the image has been re-sized and the information is no longer available then you should receive the following when echoing the same:

Camera Used: Unavailable
Exposure Time: Unavailable
Aperture: Unavailable
ISO: Unavailable
Date Taken: Unavailable

Some cameras do not capture all the information, for instance Blackberry phones do not record an aperture, or iso and you will get Unavailable for those fields. 

I hope you find this helpful.
up
0
mafo at mafo removethis dot sk
7 years ago
some cameras (most higher models) have position senzor (gyroskope?) and taking-position is wrote in EXIF, here is simple script for automatic rotating images

<?php
$exif
= exif_read_data($filename);
$ort = $exif['IFD0']['Orientation'];
    switch(
$ort)
    {
        case
1: // nothing
       
break;

        case
2: // horizontal flip
           
$image->flipImage($public,1);
        break;
                               
        case
3: // 180 rotate left
           
$image->rotateImage($public,180);
        break;
                   
        case
4: // vertical flip
           
$image->flipImage($public,2);
        break;
               
        case
5: // vertical flip + 90 rotate right
           
$image->flipImage($public, 2);
               
$image->rotateImage($public, -90);
        break;
               
        case
6: // 90 rotate right
           
$image->rotateImage($public, -90);
        break;
               
        case
7: // horizontal flip + 90 rotate right
           
$image->flipImage($public,1);   
           
$image->rotateImage($public, -90);
        break;
               
        case
8:    // 90 rotate left
           
$image->rotateImage($public, 90);
        break;
    }

?>

$image->rotateImage() is inspired by example of http://php.net/manual/en/function.imagerotate.php
$image->flipImage() is inspired by http://php.net/manual/en/function.imagecopy.php#42803 (thank you)
up
-1
Clive dot Moore at ma-design dot com
9 months ago
Following up on darkain at darkain dot com  script for grabbing the ShutterSpeedValue from exif data...
@http://php.net/manual/en/function.exif-read-data.php

I have found that the option shown for ShutterSppedValue, can also be ExposureTime in the exif data.

Also the code as written provides a WRONG return, as the return is always 1 so you get 1/1sec.

Here is corrected code, or a version that corrects what is obviously not working after 5 years since it was originally developed::

Here is the updated version for:: $exif[ExposureTime]

    function exif_get_float($value) {
        $pos = strpos($value, '/');
        if ($pos === false) return (float) $value;
        $a = (float) substr($value, 0, $pos);
        $b = (float) substr($value, $pos+1);
    return ($b == 0) ? ($a) : ($a / $b);
    };

    function exif_get_exposureTime(&$exif) {
        if (!isset($exif['ExposureTime'])) return false;
        $apex    = exif_get_float($exif['ExposureTime']);           
        $shutter = 1/$apex;
        // above 1 sec exposure time::
        if ($shutter <= 1) return round($apex) . ' seconds';

    return '1/' . round(1 / $apex) . 'sec';
    };
up
-1
hoangvu4000 at gmail dot com
1 year ago
This is function, resize image and don't rotates images have exif info

PHP must be enabled:
extension=php_mbstring.dll
extension=php_exif.dll

<?php
function CreateThumbnail($pic,$thumb,$thumbwidth, $quality = 100)
{

       
$im1=ImageCreateFromJPEG($pic);

       
//if(function_exists("exif_read_data")){
               
$exif = exif_read_data($pic);
                if(!empty(
$exif['Orientation'])) {
                switch(
$exif['Orientation']) {
                case
8:
                   
$im1 = imagerotate($im1,90,0);
                    break;
                case
3:
                   
$im1 = imagerotate($im1,180,0);
                    break;
                case
6:
                   
$im1 = imagerotate($im1,-90,0);
                    break;
                }
                }
       
//}
       
$info = @getimagesize($pic);

       
$width = $info[0];

       
$w2=ImageSx($im1);
       
$h2=ImageSy($im1);
       
$w1 = ($thumbwidth <= $info[0]) ? $thumbwidth : $info[0]  ;

       
$h1=floor($h2*($w1/$w2));
       
$im2=imagecreatetruecolor($w1,$h1);

       
imagecopyresampled ($im2,$im1,0,0,0,0,$w1,$h1,$w2,$h2);
       
$path=addslashes($thumb);
       
ImageJPEG($im2,$path,$quality);
       
ImageDestroy($im1);
       
ImageDestroy($im2);
}
?>
up
0
gimpster at gimpster dot com
10 years ago
I've written a library in pure PHP5 for editing EXIF tags. It deals with both reading and writing EXIF tags, and can be downloaded from http://pel.sourceforge.net/
up
-1
kurt at mandella dot biz
1 year ago
Photos processed in Picasa often contain garbage data in the "MAKERNOTE" section and under EXIF.MakerNote, (UTF8) like:

[MakerNote] => r0~Þæ"î2OÔy     e §…b!    )    ) EI "ÐÓ
#s &0{ 'Û (å -Ð`ÿÿ@ÿÿÿìE è€Ýÿÿ  ÿÿÿÿÿÿx "ú»Dóÿ H ?.}BúIMG:DIGITAL IXUS 100 IS JPEGFirmware Version 1.00s›xÇØÿÿÿ–l¥ÿÿÿ  ØÌÌxŒ ÿÿÌÌŸãÿÿÿ¼Ž(½ (½T‹U’‹d–~Ø“¥ÿÿÿ    ÀÿœªãjáÀpgaXfaWb[Te«
8ú5:Áð-3åÿÿ5»ÿ ‹;ßÊ Š €à€`         ¸ ddîÿîÿîÿîÿîÿîÿ
ÿÿŠ1—ÏàôÉæ׬gªiï

This can't be written to Blob in MySql. The following code removes the garbage tags.

$exif = exif_read_data($process_photo, 0, 'EXIF');

if($exif['IFD0']['Software'] == "Picasa"){

foreach ($exif as $key => $section){

if($key != "MAKERNOTE"){
  foreach ($section as $name => $val){
   if($name != 'MakerNote'){
    $exifA[$key][$name] = $val;
   }
  }
  $exifB[$key] = $exifA[$key];
}
}
$serialized_exif = serialize ($exifB);
}else{
$serialized_exif = serialize ($exif);
}
up
0
noway at nowaysoft dot com
10 years ago
Exif is very unstable under php4.1.2

If you have some problem, (the function didnt return anything, like a blocking call) try this:

$file = './image.jpg';
getimagesize ( $file , $info);

$exif = array();
if (isset($info)) {
    foreach($info as $key => $val) {
        if ($key != 'APP1') { $exif = read_exif_data($file); break; }
    }
}

-- Sharp
up
-1
Anonymous
7 years ago
When reading EXIF information from the 'WINXP' group, you may need to change used encoding from the default "ISO-8859-15" to "UTF-8". This can be done in php.ini or in your code:

<?php
    ini_set
('exif.encode_unicode', 'UTF-8');

   
$exif = exif_read_data('TEST.JPG', 0, true);
    echo
$exif['WINXP']['Title'];
?>

Useful documentation about EXIF:
http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/EXIF.html
See also comments next to XPTitle and XPAuthor.
up
-1
wdierkes at 5dollarwhitebox dot org
7 years ago
Using the exif methods to read WINXP data returns unexpected results unless both exif and mbstring are compiled statically.  Please reference the following bug reports:

Bug #31980
Bug #23105


Specifically, the last comment on #23105:

"[8 Apr 2003 4:26pm UTC] edink@php.net

This cannot be fixed due to the fact that mbstring has been removed from PHP core (it has been 'unbundled') and the rest of core files and other extensions cannot use mbstring functionality when it is compiled as a shared library (dll).
"

If exif is compiled statically (--enable-exif) and mbstring compiled as a DSO module (--enable-mbstring=shared) then exif_read_data may only return a single character rather than the entire string.

Compiling both exif and mbstring statically (--enable-exif --enable-mbstring) resolves the issue.
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-3
pekka at photography-on-the dot net
10 years ago
For reading EXIF from XMP data embedded by Adobe Photoshop CS, see  http://www.photography-on-the.net/ee/beta/cs_xmp_to_exif.php
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