Resize filter in VirtualDubMod

[CSULB71]

I have an XviD AVI that I converted from a low quality (~250 kbps) YouTube clip that is 320x240 in size, and I want to enlarge it to 360x240 to correct the aspect ratio, and maybe go a little larger, proportionally.
Two questions: (1) do I apply the resize filter first before any other filters, or last? I've seen both ways recommended.
(2) do I use the "plain" Bicubic method, or will one of the three "Precise Bicubic" options give a better quality for this clip?
Thanks.

[guns1inger]

If you are using a deblock filter, resize afterwards. Deblockers are based on standard DCT block sizes, and this will be changed if you resize first.

Personal preference for enlarging is Lanczos as it gives a sharper result.

[Soopafresh]

At that postage stamp size dimension, it won't matter the order or type of resizer you apply. Here's a couple of experiments you can try:



Run the resizer twice in VirtualDub - (btw, Lanczos3 is a bit better than the bicubic resizers)


Resize to Double the dimensions

Apply noise reduction

Resize to your desired dimensions


The theory behind this is that the artifacts caused by your noise reduction program will be less noticeable if you apply the NR when the image is larger.


You can also try VideoEnhancer by Deemon for 30 days. It does very high quality resizing and also works with VirtualDub plugins: http://www.thedeemon.com/VideoEnhancer/

[CSULB71]

I've been using Lanczos3 for enlarging for several years because I thought the results looked a little better than Bicubic -- glad to see others think so, too.
Is Bilinear the preferred method for reducing (just wondering), or does Lanczos3 work better there, too?
Soopafresh -- I'll give your suggestion a try.
Thanks.

[jagabo]

You could also encode at the source frame size and use the Xvid DAR flags so that the player resizes at playback time. Some players do not respect the DAR flag though.

[jagabo]

Is Bilinear the preferred method for reducing (just wondering), or does Lanczos3 work better there, too?

It depends on whether you want sharper and harder to compress (lanczos3), or softer and easier to compress (bilinear).