Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 Doom9's Forum Quick question: What is the difference between interpolating and blending?
 Register FAQ Calendar Search Today's Posts Mark Forums Read

 8th March 2005, 01:51 #1  |  Link jellysandwich Registered User   Join Date: Mar 2004 Posts: 247 Quick question: What is the difference between interpolating and blending? Googles didn't help much jellysandwich
 8th March 2005, 03:18 #2  |  Link trevlac budala   Join Date: Oct 2003 Location: U.S. Posts: 545 Depends on the context. For deinterlacing I believe these mean the same thing. For resizing, they would not. Lanczos would be interpolation, bilinear would be blend. BTW: Interpolate usually means calculating a new pixel value between and by using other pixels. If certain conditions are met, the calculation can be rather accurate. The secret is that the surounding pixels are not evenly weighted (not a simple average), and many are used. "A simple average" i would take as the general meaning of blend. Unfortunately, for deinterlacing, there is not enough information to do a proper interpolation. AKA the frame rate is too low. For deinterlacing ... other math magic has to me used. Like motion compensation. At least that's my take ..
 8th March 2005, 05:40 #3  |  Link jellysandwich Registered User   Join Date: Mar 2004 Posts: 247 Hmm, that's a bit weird since the reason I'm asking is because of Decomb's blend=true/false option... jellysandwich
 8th March 2005, 05:45 #4  |  Link E-Male mad computer-scientist   Join Date: Mar 2002 Posts: 1,375 AFAIK(!): blending means taking 2 or more pixels (or other sources) and combine them (for example by averaging) interpolating means that you take 2 sources a and c and reconstruct b from them (trying to get d would be extrapolating) so depending on the context it should be the same
 8th March 2005, 05:46 #5  |  Link jellysandwich Registered User   Join Date: Mar 2004 Posts: 247 Another question To avoid making a new thread... What is this called, and how can I get rid of it? http://whitevoid.myvnc.com/stuff/this.JPG The left picture is the source, unmodified. After trying a bunch of plugins and scripts, I always end up getting something like the right picture. At first, I thought it was blending, but now I'm not so sure, since I can't seem to get rid of it no matter what I do... You can imagine what the previous/next frames are. Anyway, I'd like to make/use a script/plugin that chooses either the previous or the next frame, instead of having to use a combination of both. Is that possible? jellysandwich
 8th March 2005, 06:31 #6  |  Link tritical Registered User   Join Date: Dec 2003 Location: MO, US Posts: 999 Pretty sure that part of the hellsing intro contains blended fields (you can verify it by using separatefields() and examining them), which is what is causing the effect in your pics...
 8th March 2005, 07:12 #7  |  Link Manao Registered User   Join Date: Jan 2002 Location: France Posts: 2,856 Blending and interpolating are totally different in the context of deinterlacing : - blending : you merge both fields together ( hence it's a very basic kind of spatio temporal interpolation ). You will likely end up with ghosts on fast action scenes. - interpolation : you discard one field and reconstruct it with the other, spatially ( so only spatial interpolation ). No ghosts ( except of course if the source has got blended fields, but that's another matter ), but less details too.
9th March 2005, 00:31   #8  |  Link
jellysandwich
Registered User

Join Date: Mar 2004
Posts: 247
Quote:
 Originally posted by tritical Pretty sure that part of the hellsing intro contains blended fields (you can verify it by using separatefields() and examining them), which is what is causing the effect in your pics...
Ok, I just checked it, and I think you're right.

So, let me rephrase my previous question then...
Is there a way of getting rid of those blended
fields by using the next/previous unblended fields?

Manao, thanks, your explanation helped a lot.

jellysandwich

 9th March 2005, 00:37 #9  |  Link Guest Guest   Join Date: Jan 2002 Posts: 21,923 Do a search on "blended fields".
 9th March 2005, 00:38 #10  |  Link jellysandwich Registered User   Join Date: Mar 2004 Posts: 247 Of course there is. I got it, thanks a bunch. jellysandwich