Edit exif data of an image [duplicate] - php

Question

On our site, we get a large amount of photos uploaded from various sources.
In order to keep the file sizes down, we strip all exif data from the source using mogrify:
mogrify -strip image.jpg
What we'd like to be able to do is to insert some basic exif data (Copyright Initrode, etc) back onto this new "clean" image, but I can't seem to find anything in the docs that would achieve this.
Has anybody any experience of doing this?
If it can't be done through imagemagick, a PHP-based solution would be the next best thing!
Thanks.

Answer 1

You can save a large amount of space, especially if you have a large number of images..
Add the following to text.txt (format of the IPTC tags taken from here):
2#110#Credit="My Company"
2#05#Object Name="THE_OBJECT_NAME"
2#55#Date Created="2011-02-03 12:45"
2#80#By-line="BY-LINE?"
2#110#Credit="The CREDIT"
2#115#Source="SOURCE"
2#116#Copyright Notice="THE COPYRIGHT"
2#118#Contact="THE CONTACT"
2#120#Caption="AKA Title"
Strip all existing exif data from the image
mogrify -strip image.jpg
Add the credit to your image
mogrify -profile 8BIMTEXT:text.txt image.jpg

Answer 2

Exiftool looks like it would be an exact match for you.
I haven't tried it but I'm now tempted to go and fix all my honeymoon photos which are marked 01/01/2074 because I forgot to reset the date after the batteries died.

Answer 3

Here's a PHP Exif Library that should do what you need.
The PHP Exif Library (PEL) lets you
fully manipulate Exif (Exchangeable
Image File Format) data. This is the
data that digital cameras place in
their images, such as the date and
time, shutter speed, ISO value and so
on.
Using PEL, one can fully modify the
Exif data, meaning that it can be both
read and written. Completely new Exif
data can also be added to images. PEL
is written completely in PHP and
depends on nothing except a standard
installation of PHP, version 5. PEL is
hosted on SourceForge.

Answer 4

on linux there is a program called jhead. It can add a minimal exif header with the command:
jhead -mkexif img.jpg

Answer 5

I doubt you will gain lot of space by removing Exif information...
Anyway, I can be wrong, but Exif metadata belongs more to store technical (and contextual) information. For stuff like copyright, you should use IPTC instead.
That's something you can do, apparently, with ImageMagick: Write IPTC Data to Jpeg with ImageMagick.

Answer 6

You can do this directly in PHP using the PEL library. You would do this by simply overwriting the existing EXIF-headers,
// Load image data
$data = new PelDataWindow(file_get_contents('IMAGE PATH'));
// Prepare image data
$jpeg = $file = new PelJpeg();
$jpeg->load($data);
// Create new EXIF-headers, overwriting any existing ones (when writing to disk)
$exif = new PelExif();
$jpeg->setExif($exif);
$tiff = new PelTiff();
$exif->setTiff($tiff);
// Create Ifd-data that will hold EXIF-tags
$ifd0 = new PelIfd(PelIfd::IFD0);
$tiff->setIfd($ifd0);
// Create EXIF-data for copyright
$make = new PelEntryAscii(PelTag::COPYRIGHT, '2008-2017 Conroy');
$ifd0->addEntry($make);
// Add more EXIF-data...
// Save to disk
$file->saveFile('IMAGE.jpg');
You can find a complete list of all supported EXIF-data (PelTag) in the PEL docs.