Flicker reduction

[Chris Northcross]

I finally got some time to plunge into SA again this weekend and it was one of the highlights of the week for me. In looking back at some of the clips that I've created, I noticed that I'm still producing a lot of flicker. I've tried lowering the frame rate that the clips render at and adding some overpainting but haven't quite found the look I'm searching for. Anyone have any hints/tips/recipes they care to share?

[Synthetik]

Are you doing painting or image processing or vectorizer or what? For painting, overdrawing on a modified version of the previous output frame is a great way to cut down flicker. The examples in the Process Movies Tutorial pdf in the studio artist documentation folder is a great place to get started with that, since all of the examples in that short pdf are available as presets to play around with. You might want to cut down or eliminate paint stroke color randomization. Time Particles are another way to cut down flicker in paint animations.

If you are running the vectorizer or ip ops, you want to make sure the Random popup in the secondary control area (below the main parameter control panel on the bottom left) is set to Use Seed. This will in sure the same random number seed is used for any operations that use internal random numbers. Setting this is important for operations like Color Simplify to get the best results on video.

[David Kaplan]

i would suggest looking through the old studio artist forum at digital media net (http://www.dmnforums.com/cgi-bin/displaywwugindex.fcgi?endday_index...) and doing a search for "flicker" or something like that. you'll get a trove of information that way: http://forums.digitalmedianet.com/cgi-bin/search/wwugsearchresults....

[john]

I had an idea about this, and I'm not sure if it's possible already or a suggestion for SA 4:

Example: when 'processing movie with a paint action seq' , say one step is using a paint synthesizer, if SA could reference the brush strokes of the previous frame as well as the current frame that it SA is painting. So say SA makes a red vertical stroke to represent the image in frame one , SA would compare what it did for frame one, and the source image for frame 2 to autopaint the new frame 2. Maybe you'd be able to set how similar each rendering would be from the previous frame in a pop up window.

Can you do something like this already?

[Synthetik]

If you're painting with time particles on in the paint synthesizer then the old paint strokes (or path start points depending on how its configured) stay around from frame to frame.

[Victor Ingrassia]

Hi Chris,

Some of this may seem obvious... but here are some general principles which
might help.

--A general tip about "calming down" the paint in SA is to experiment with
paseq's that do not erase the canvas completely to white (or black or
source) between frames. The most extreme version is this is to erase
nothing between frames... to simply overpaint the last frame. This will
work with only certain types of source video and certain paseq's. But you
can compromise a bit and use a less than 100% of white or black (via the
Fixed Color" Image Operation) between frames to lighten or darken (instead
of erase) the previously painted frame. Also, applying other ImOp's like
Smart Blur or Blur before overpainting can help melt the previous frame's
paint, make it recede into the background and, indirectly, keep things
calm and keep the viewer focussed on the newer paint.

--Using paint strokes that are not 100% opaque is helpful too. Try turning
down the % of blend (Paint Synthesizer control "Paint Fill
Apply">Composite:Blend>Blend%). You'll have to develop and test to arrive
at the correct combination of blend, path count, fixed color, and fps.

--Sometimes you can use some macro's to tweak individual paint patches (Edit
/ Paint Synthesizer/ MacroEdit / Edge Focus, or Edit / Paint Synthesizer/
MacroEdit /Turn Off Randomization, for instance).

--Reducing your frames per second can help too. You can animate at (let's
say) 6-15 fps, then use SA's tweening feature ("run layer tween morph"... do
a search in the SA manual pdf) to insert frames which will blend the
animated frames together while adding frames.

-- This one is very important. Selecting (or creating) source video that is
clean, well lit, steady and graphically strong, can also go a long way to
settling things down. The cleaner the source the less the paint strokes
will vary from frame to frame.

-- Explore the powerful Image Operations section of SA, SIMPLIFY, RANK
AREA, SMART CONTRAST, SMOOTH are image op's which create cleaner
effects with a more cartoonish look... and they involve no paint strokes. You
can sometimes add one of these im op's as a step in a paseq along with
painting steps.

I hope some of these help.

~victor