php: recreate and display an image from binary data

Question

Is it possible to recreate images from binary data (process them if needed) and display them, all in the same script? Something like

// get and display image 1:
$imagedata1 = file_get_contents('assets/test.png');
$imagedata1 = process_using_gd_or_something($imagedata1);

echo "<img src={$imagedata1} >"; // <-- IS THIS (OR EQUIVALENT) POSSIBLE?

// get and display image 2:
//etc...

I want to avoid storing the images to to disk after processing and getting them from there, or using an external script...

Answer 1

You can do this using a data URI in the image src attribute.

The format is: data:[<MIME-type>][;charset="<encoding>"][;base64],<data>

This example is straight from the Wikipedia page on data URIs:

<?php
function data_uri($file, $mime) 
{  
  $contents = file_get_contents($file);
  $base64   = base64_encode($contents); 
  return ('data:' . $mime . ';base64,' . $base64);
}
?>

<img src="<?php echo data_uri('elephant.png','image/png'); ?>" alt="An elephant" />