View Single Post
Old 30th March 2011, 12:43   #545  |  Link
hydra3333
Registered User
 
Join Date: Oct 2009
Location: crow-land
Posts: 540
Quote:
Originally Posted by Gavino View Post
1. Would there be any advantage (or disadvantage) in doing the Blur before the resize?

2. Given you have to vertically blur the results, is there in fact any point in using (Q)TGMC for deinterlacing just in order to do an re-interlaced downsize? Would an 'inferior' but faster deinterlacer give equally good results, or do you still gain something from the temporal processing of (Q)TGMC?
I'd be interested in knowing 'expert' the answers to these questions too. I suspect with 1, it might be a lot slower but I'm not sure of the gain.

Also interestingly, this much faster Brute-Force approach doesn't suffer from the QTGMC jaggies and looks "reasonable".
I really should compare the QTGMC-blur with this brute-force, side by side...
Code:
# BRUTE-FORCE PURE VERSION PER http://forum.doom9.org/showthread.php?p=1185790#post1185790  
Global NewHeight=576 
Global NewWidth=720 
SeparateFields()  
Shift = (GetParity() ? -0.25 : 0.25) * (Height()/Float(NewHeight/2)-1.0) 
E  = SelectEven().Spline36resize(NewWidth, NewHeight/2, 0,    Shift) 
O  = SelectOdd( ).Spline36resize(NewWidth, NewHeight/2, 0,   -Shift) 
Ec = SelectEven().Spline36Resize(NewWidth, NewHeight/2, 0,  2*Shift) 
Oc = SelectOdd( ).Spline36Resize(NewWidth, NewHeight/2, 0, -2*shift) 
Interleave(E, O) 
IsYV12() ? MergeChroma(Interleave(Ec, Oc)) : Last 
Weave() 
AssumeTFF()

edit: Compared with stackhorizontal and frame-by-frame - the QTGMC-noblur looks nicest and sharpest in places with no motion however in places of motion with lines it is striking in how the jaggies stand out. The QTGMC-blur and Brute-Force appear almost identical to most intents and purposes (relatively clean 1440x1080i source). So... in this instance with this type of source with the intent of an interlaced size reduction from HDi to SDi, I can attain circa 20x the speed by abandoning QTGMC and going brute-force. Obvious I suppose, but as a dummy I'd thought "yeah, I want quality, just knock it about with QTGMC to get a great deinterlaced image for size-reduction and reinterlacing".

Last edited by hydra3333; 30th March 2011 at 13:53.
hydra3333 is offline