ethics-canvas/canvas/mpdf/examples/example40_MPDFI_thumbnails.php

<?php

// required to load FPDI classes
require_once __DIR__ . '/../vendor/autoload.php';

$mpdf = new mPDF();

$mpdf->SetImportUse();

$mpdf->Thumbnail('sample_orientation2.pdf', 4, 5);	// number per row	// spacing in mm

$mpdf->WriteHTML('<pagebreak /><div>Now with rotated pages</div>');

$mpdf->Thumbnail('sample_orientation3.pdf', 4);	// number per row	// spacing in mm

$mpdf->WriteHTML('<pagebreak /><div>Now with more rotated pages</div>');

$mpdf->Thumbnail('sample_rotated.pdf', 4);	// number per row	// spacing in mm

$mpdf->Output();