No matter where I place my overlay.png file (in the root of the bucket or in the folder of the input/output) the Watermark is not being applied using the following code:
$watermark = array(
    'InputKey' => "overlay.png",
    'PresetWatermarkId' => 'TopLeft'
);
# Create the job.
$create_job_request = array(
    'PipelineId' => $pipeline_id,
    'Input' => $input,
    'Watermarks' => array($watermark),
    'Outputs' => $outputs,
    'OutputKeyPrefix' => "$output_key_prefix"
);
The output is being created just fine, just without the watermark. Any Information on where I have to put the overlay.png file ?
Thanks in advance