Jpeg images don't support property writing?

[Danack]

The below should work, right?

$formats = [
    'jpg',
    'png'
];

foreach ($formats as $format) {
    $im = new Imagick();
    $im->newimage(50, 50, 'blue');
    $im->setimageformat($format);
    $im->setImageProperty('Exif:Make', 'a property');
    $im->writeimage('./output.'.$format);
    $im->destroy();
    $im2 = new Imagick('./output.'.$format);
    printf("Format %s *****\n", $format);
    printf("Property value %s\n", var_export($im2->getImageProperty('Exif:Make'), true));

    $im2->destroy();
}

Format jpg *****
Property value false
Format png *****
Property value 'a property'

[Danack]

For Jpeg, the only property that is persisted is one named 'comment'.

$propertyNames = [
    "comment",
    "anything_else"
];

$formats = [
    'jpg',
    'png'
];

foreach ($formats as $format) {
    foreach ($propertyNames as $propertyName) {
        $imagick = new Imagick('./LittleRobin.jpg');
        $imagick->setImageProperty($propertyName, "Modified value");
        $imagick->setFormat($format);
        $imagick->writeImage("./testModified.".$format);
        $imagick2 = new Imagick("./testModified.".$format);
        printf(
            "After reloading '%s' property '%s' is:%s\n",
            $format,
            $propertyName,
            var_export($imagick2->getImageProperty($propertyName), true)
        );
    }
}

[Danack]

To summarise:

• Jpegs only support writing comments
• Exif information is never updated.

Those two bits of info need to be added to http://php.net/manual/en/imagick.setimageproperty.php

Source of info: ImageMagick/ImageMagick#55