Quick question: What is the difference between interpolating and blending?

[jellysandwich]

Googles didn't help much :(

jellysandwich

[trevlac]

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 .. :)

[jellysandwich]

Hmm, that's a bit weird since the reason I'm asking
is because of Decomb's blend=true/false option...

jellysandwich

[E-Male]

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

[jellysandwich]

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

[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...

[Manao]

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.

[jellysandwich]

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

[Guest]

Do a search on "blended fields".

[jellysandwich]

Of course there is. I got it, thanks a bunch.

jellysandwich