<p>IIRC Cycles uses "filter importance sampling" to do its sample filtering. This has some advantages, but one of its disadvantages is that it doesn't work well with filters that have negative lobes (the resulting renders are very noisy).</p>
<p>All the filters you mention have negative lobes, so although they technically could be implemented, my guess is that they won't be. It would be very unexpected behavior to a user if they switched filters and suddenly their image was twice as noisey.</p>
<p>--Nathan</p>
<div class="gmail_quote">On Aug 6, 2015 7:38 AM, "Yury Baranov" <<a href="mailto:cucumberer@gmail.com">cucumberer@gmail.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi. Is it planned to make more sample filtering options like catmull-rom, sinc, lanczos etc.? Maybe more filtering options for bitmaps will be good, too.</div>
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