To get png images to work I had to save them as indexed colour (128 colours).
(PECL ps >= 1.1.0)
ps_place_image — Places image on the page
Places a formerly loaded image on the page. The image can be scaled. If the image shall be rotated as well, you will have to rotate the coordinate system before with ps_rotate().
psdocResource identifier of the postscript file as returned by ps_new().
imageidThe resource identifier of the image as returned by ps_open_image() or ps_open_image_file().
xx-coordinate of the lower left corner of the image.
yy-coordinate of the lower left corner of the image.
scaleThe scaling factor for the image. A scale of 1.0 will result in a resolution of 72 dpi, because each pixel is equivalent to 1 point.
To get png images to work I had to save them as indexed colour (128 colours).If you want to make a template with graphics software and place it on your PostScript page, one way to do it is with an eps file.
<?php
$template = ps_open_image_file($ps, 'eps', 'template.eps');
ps_place_image($ps, $template, 0, 0, 1);
?>
Professional page layout software such as InDesign will typically be able to generate an eps file. If your software can't, one way to do it (on Windows) is to set up a printer that prints to file with the driver "Lexmark Color 4079 plus PS". This driver is included with Windows and has the option in its advanced preferences to generate an EPS file.