Quick and dirty GDImage to Base64 URL.

quick_image_to_base64.php

<?php

function image_to_base64( $image, $type = 'image/jpeg' ) {

	// Use new buffer to grab the output.
	ob_start();
	switch ( $type ) {
		case 'image/jpeg':
			imagejpeg( $image );
			break;
		case 'image/png':
			imagepng( $image );
			break;
	}

	// Get buffer contents.
	$image_data = ob_get_contents();

	// Drop the buffer.
	ob_end_clean();

	if ( ! empty( $image_data ) ) {
		return 'data:' . $type . ';base64,' . base64_encode( $image_data );
	}

	return false;
}