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.
exif_read_data
(PHP 4 >= 4.2.0, PHP 5, PHP 7)
exif_read_data — Lee las cabeceras EXIF desde un JPEG o un TIFF
Descripción
exif_read_data
( string
$filename
[, string $sections = NULL
[, bool $arrays = false
[, bool $thumbnail = false
]]] ) : arrayexif_read_data() lee las cabeceras EXIF desde un archivo de imagen JPEG o TIFF. De esta forma se puede leer los meta-datos generados por cámaras digitales.
Las cabeceras EXIF tienden a estar presentes en imágenes JPEG/TIFF generadas por cámaras digitales, pero desafortunadamente cada fabricante de cámaras digitales tiene una idea diferente de cómo etiquetar sus imágenes, por lo que no siempre se puede contar con que una cabecera Exif específica esté presente.
Height y Width son computados de la misma forma que lo hace getimagesize() por lo que sus valores no deben ser parte de ninguna cabecera devuelta. También, html es una cadena de texto de alto/ancho para usar dentro de un HTML normal.
Cuando una cabecera Exif contiene una nota de Copyright, puede contener ella misma dos valores. Como la solución es inconsistente en el estándar Exif 2.10, la sección COMPUTED devolverá las dos entradas Copyright.Photographer y Copyright.Editor mientras que las secciones IFD0 contienen la matriz de bytes con el carácter NULL que divide ambas entradas. O sólo la primera entrada si el tipo de información era erróneo (el comportamiento normal de Exif). COMPUTED también contendrá la entrada Copyright que es la cadena del copyright original, o una lista separada por comas del copyright de la fotografía y del editor.
La etiqueta UserComment tiene el mismo problema que la etiqueta Copyright. Puede almacenar dos valores. El primero es el que usa la codificación, y el segundo es el valor mismo. Por lo que si la sección IFD sólo contiene la codificación o una matriz de bytes, la sección COMPUTED almacenará la dos entradas UserCommentEncoding y UserComment. La entrada UserComment está disponible en ambos casos por lo que se debería usar con preferencia al valor de la sección IFD0.
exif_read_data() también valida las etiquetas de información EXIF según la especifiación EXIF (» http://exif.org/Exif2-2.PDF, página 20).
Nota:
Windows Me/XP pueden borrar las cabeceras Exif cuando se conecta una cámara.
Parámetros
-
filename -
El nombre de la imagen que se va a leer. No puede ser una URL.
-
sections -
Es una lista separada por comas de las secciones que necesitan estar presentes en el archivo para producir un array resultante. Si no se puede encontrar ninguna sección el valor devuelto es
FALSE.FILE FileName, FileSize, FileDateTime, SectionsFound COMPUTED html, Width, Height, IsColor, y más si están disponibles. Height y Width son computados de la misma forma que lo hace getimagesize() por lo que sus valores no deben ser parte de ninguna cabecera devuelta. También, html es una cadena de texto de alto/ancho para usar dentro de un HTML normal. ANY_TAG Cualquier información que tenga una Etiqueta, p.ej., IFD0, EXIF, ... IFD0 Toda la información etiquetada de IFD0. En archivos de imagen normales, ésto contiene el tamaño de la imagen y así sucesivamente. THUMBNAIL Se supone que un archivo contiene una miniatura si tiene un segundo IFD. Toda la información etiquetada acerca de la miniatura embebida es almacenada en esta sección. COMMENT Cabeceras de comentarios de imágenes JPEG. EXIF La sección EXIF es una subsección de IFD0. Contiene información más detallada sobre la imagen. La mayoría de estas entradas están relacionadas con la cámara digital. -
arrays -
Especifica si cada sección se convierte o no en una matriz.
sectionsCOMPUTED, THUMBNAIL, y COMMENT siempre se convierten en matrices ya que pueden contener valores cuyos nombres entran en conflicto con otras secciones. -
thumbnail -
Cuando se establece a
TRUEse lee la miniatura misma. Si no, sólo se lee la información etiquetada.
Valores devueltos
Devuelve un array asociativo donde los índices de la matriz son
los nombres de las cabeceras y los valores de la matriz son los valores asociados con
esas cabeceras. Si no se puede devolver información,
exif_read_data() devolverá FALSE.
Historial de cambios
| Versión | Descripción |
|---|---|
| 4.3.0 | Se puede leer toda la información IFD embebida incluidas matrices (devueltas como tales). También, el tamaño de una miniatura embebida es devuelto en una submatriz THUMBNAIL, y puede devolver miniaturas en formato TIFF. Además, ya no hay una longitud máxima para los valores devueltos (no mientras el límite de memoria haya sido alcanzado) |
| 4.3.0 | Si PHP tiene soporte para mbstring, el comentario de usuario puede cambiar automáticamente de codificación. También, si el comentario de usuario utiliza la codificación Unicode o JIS, esta codificación será cambiada automáticamente según la configuración inicial de exif en php.ini |
| 4.3.0 | Si la imagen contiene cualquier información IFD0, entonces COMPUTED contiene la entrada ByteOrderMotorola la cuál es 0 para el orden de byte little-endian (intel) y 1 para el orden de byte big-endian (motorola). También, COMPUTED y UserComment ya no contienen la primera entrada de copyright si el tipo de información era erróneo. |
Ejemplos
Ejemplo #1 Ejemplo de exif_read_data()
<?php
echo "prueba1.jpg:<br />\n";
$exif = exif_read_data('pruebas/prueba1.jpg', 'IFD0');
echo $exif===false ? "No se encontró información de cabecera.<br />\n" : "La imagen contiene cabeceras<br />\n";
$exif = exif_read_data('pruebas/prueba2.jpg', 0, true);
echo "prueba2.jpg:<br />\n";
foreach ($exif as $clave => $sección) {
foreach ($sección as $nombre => $valor) {
echo "$clave.$nombre: $valor<br />\n";
}
}
?>
La primera llamada falla ya que la imagen no tiene información de cabecera.
El resultado del ejemplo sería algo similar a:
test1.jpg: No header data found. test2.jpg: FILE.FileName: test2.jpg FILE.FileDateTime: 1017666176 FILE.FileSize: 1240 FILE.FileType: 2 FILE.SectionsFound: ANY_TAG, IFD0, THUMBNAIL, COMMENT COMPUTED.html: width="1" height="1" COMPUTED.Height: 1 COMPUTED.Width: 1 COMPUTED.IsColor: 1 COMPUTED.ByteOrderMotorola: 1 COMPUTED.UserComment: Exif test image. COMPUTED.UserCommentEncoding: ASCII COMPUTED.Copyright: Photo (c) M.Boerger, Edited by M.Boerger. COMPUTED.Copyright.Photographer: Photo (c) M.Boerger COMPUTED.Copyright.Editor: Edited by M.Boerger. IFD0.Copyright: Photo (c) M.Boerger IFD0.UserComment: ASCII THUMBNAIL.JPEGInterchangeFormat: 134 THUMBNAIL.JPEGInterchangeFormatLength: 523 COMMENT.0: Comment #1. COMMENT.1: Comment #2. COMMENT.2: Comment #3end THUMBNAIL.JPEGInterchangeFormat: 134 THUMBNAIL.Thumbnail.Height: 1 THUMBNAIL.Thumbnail.Height: 1
Ver también
- exif_thumbnail() - Recuperar la miniatura embebida de una imagen TIFF o JPEG
- getimagesize() - Obtener el tamaño de una imagen
add a note
User Contributed Notes 17 notes
chadsmith729 at gmail dot com ¶
7 years ago
darkain at darkain dot com ¶
12 years ago
I wanted some quick and easy functions for computing the shutter speed and f-stop. I couldn't find any anywhere, so I made some. It took some research :
<?php
function exif_get_float($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);
}
?>
b at asdflolinternet dot de ¶
4 years ago
Problem with "S�o�m�e� �T�e�x�t��" on value(s), exif[IFD0][Title] for example, when they were edited trough windows right click properties and then got read with the read_exif_data() function.
try:
$exif_['IFD0']['Title']=mb_convert_encoding($exif_['IFD0']['Title'],"auto","byte2le");
works on UTF-8 and so.
//
// outputs all available character encodings and prints on screen
// foreach(mb_list_encodings() as $chr)
// {$test[$chr]=mb_convert_encoding($image[IFD0][Title],'auto',$chr);}
// exit(print_r($test));
//
drpain at webster dot org dot za ¶
8 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.
Eion Robb ¶
5 years ago
I was needing to use exif_read_data() to read out the orientation flag, only to find that the webhost didn't have the exif extension available for use. Instead, I hacked up a regex that worked fairly well as a replacement
<?php
$orientation = 1;
if (function_exists('exif_read_data')) {
$exif = exif_read_data($filename);
if (isset($exif['Orientation']))
$orientation = $exif['Orientation'];
} else if (preg_match('@\x12\x01\x03\x00\x01\x00\x00\x00(.)\x00\x00\x00@', file_get_contents($filename), $matches)) {
$orientation = ord($matches[1]);
}
?>
mafo at mafo removethis dot sk ¶
12 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)
Tim ¶
9 months ago
The following code:
<?php
$data = exif_read_data('foo.jpg');
var_dump($data['Keywords']);
?>
produces string(15) "???????????????"
Adding
<?php
ini_set('exif.decode_unicode_motorola', 'UCS-2LE');
?>
before the call to exif_red_data produces
string(15) "landscape;;field"
TNTcode ¶
2 years ago
<?php
// auto rotates an image file based on exif data from camera
// if destination file is specified then it saves file there, otherwise it will display it to user
// note that images already at normal orientation are skipped (when exif data Orientation = 1)
if(!function_exists("gd_auto_rotate")){
function gd_auto_rotate($original_file, $destination_file=NULL){
$original_extension = strtolower(pathinfo($original_file, PATHINFO_EXTENSION));
if(isset($destination_file) and $destination_file!=''){
$destination_extension = strtolower(pathinfo($destination_file, PATHINFO_EXTENSION));
}
// try to auto-rotate image by gd if needed (before editing it)
// by imagemagik it has an easy option
if(function_exists("exif_read_data")){
$exif_data = exif_read_data($original_file);
$exif_orientation = $exif_data['Orientation'];
// value 1 = normal ?! skip it ?!
if($exif_orientation=='3' or $exif_orientation=='6' or $exif_orientation=='8'){
$new_angle[3] = 180;
$new_angle[6] = -90;
$new_angle[8] = 90;
// load the image
if($original_extension == "jpg" or $original_extension == "jpeg"){
$original_image = imagecreatefromjpeg($original_file);
}
if($original_extension == "gif"){
$original_image = imagecreatefromgif($original_file);
}
if($original_extension == "png"){
$original_image = imagecreatefrompng($original_file);
}
$rotated_image = imagerotate($original_image, $new_angle[$exif_orientation], 0);
// if no destination file is set, then show the image
if(!$destination_file){
header('Content-type: image/jpeg');
imagejpeg($rotated_image, NULL, 100);
}
// save the smaller image FILE if destination file given
if($destination_extension == "jpg" or $destination_extension=="jpeg"){
imagejpeg($rotated_image, $destination_file,100);
}
if($destination_extension == "gif"){
imagegif($rotated_image, $destination_file);
}
if($destination_extension == "png"){
imagepng($rotated_image, $destination_file,9);
}
imagedestroy($original_image);
imagedestroy($rotated_image);
}
}
}
}
?>
michael [at[ thisiswilson [dot[ com ¶
11 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/
lincolnzsilva at gmail dot com ¶
11 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'];
?>
Anonymous ¶
13 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 $exif['WINXP']['Title'];
?>
Useful documentation about EXIF:
http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/EXIF.html
See also comments next to XPTitle and XPAuthor.
iam at thatguy dot co dot za ¶
6 years ago
I posted the original version of the function, but after using it for a while I discovered I didn't do enough error checking.
I have re-factored it somewhat, and it now returns an empty array should it not be able to read the image's exif. If it is able to, it will return the details it was able to retrieve. And this should be without error.
I am suppressing errors, because if you pass it images which cannot parse, you will get a warning.
<?php
# Modified Version of cameraUsed, no longer returns date.
public function cameraUsed($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 $return;
}
?>
wdierkes at 5dollarwhitebox dot org ¶
12 years ago
Using the exif methods to read WINXP data returns unexpected results unless both exif and mbstring are compiled statically. Please reference the following bug reports:
Bug #31980
Bug #23105
Specifically, the last comment on #23105:
"[8 Apr 2003 4:26pm UTC] edink@php.net
This cannot be fixed due to the fact that mbstring has been removed from PHP core (it has been 'unbundled') and the rest of core files and other extensions cannot use mbstring functionality when it is compiled as a shared library (dll).
"
If exif is compiled statically (--enable-exif) and mbstring compiled as a DSO module (--enable-mbstring=shared) then exif_read_data may only return a single character rather than the entire string.
Compiling both exif and mbstring statically (--enable-exif --enable-mbstring) resolves the issue.
hoangvu4000 at gmail dot com ¶
7 years ago
This is function, resize image and don't rotates images have exif info
PHP must be enabled:
extension=php_mbstring.dll
extension=php_exif.dll
<?php
function CreateThumbnail($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);
}
?>
omerg at lucidcode dot com dot tr ¶
1 year ago
The example provided for displaying exif array content is not working in recent version because not all entry values are of array type.
This is an alternative echo loop:
<?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";
$exif = exif_read_data('tests/test2.jpg', 0, true);
echo "test2.jpg:<br />\n";
foreach ($exif as $key => $section) {
if (!is_array ($section)) {
echo "$key: $section<br />\n";
} else {
foreach ($section as $name => $val) {
echo "$key.$name: $val<br />\n";
}
}
}
?>
Clive dot Moore at ma-design dot com ¶
6 years 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';
};
kurt at mandella dot biz ¶
7 years ago
Photos processed in Picasa often contain garbage data in the "MAKERNOTE" section and under EXIF.MakerNote, (UTF8) like:
[MakerNote] => r0~Þæ"î 2OÔy 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);
}
