Differences between FIRST postage-stamps and CUTOUTs

The FIRST CUTOUT server software is not suitable for the VDQTZ+GZIP noise- quantized and compressed image archive held here at MRAO, so we are offering access via a postage-stamp server adapted from Bill Cotton's NVSS program. Unlike the cutout server, this gives users the opportunity to specify the sampling, projection, coordinate equinox and orientation (rotation) of the extracted subimage. Note that, even if these values are left unchanged, the resulting postage stamp will be resampled so that the target position falls on an exact pixel and the y-axis through this points northwards. The postage stamp is different in this respect from a cutout from the FIRST main site's cutout server which merely extracts a set of pixels from the parent image, meaning that in general cutouts are neither north-pointing nor pixel-centred at the target position.