How can I improve the dynamic range of my output?

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mankind-nil
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How can I improve the dynamic range of my output?

Post by mankind-nil »

Hey, this is my first post, and my first animation!
I would be grateful for some input here! I did a few searches on here but couldn't find the same query.
The main issue is my background, which is made up of some blurred shapes which cycle colours (slowly!). All the colours are fairly dark, and the output (in the preview render as well as in exported non-compressed .mov file (using 'animation' codec)) has some slight banding, which I guess is to do with color bit depth or something. Are there any tricks to improve this?
If I export using the h.264 codec however, the results are much worse (even on 'best' setting)! Please see example on Vimeo

I guess there's two issues here, firstly the output from Anime, and secondly the h.264 compression codec. Any advice would be much appreciated!

I'm using Anime Studio Debut 7, on a mac, if it helps.

Thanks very much!
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Víctor Paredes
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Post by Víctor Paredes »

Maybe you should try using quicktime png compression.
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mankind-nil
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Post by mankind-nil »

Thanks for the input.
Outputting as PNG looks the same as the the uncompressed 'animation' codec, so looks ok, but some slight banding. Compressed to h.264 it still looks bad.
Am I maybe asking too much? Is it just that people don't tend to use dark gradients in the animation world?
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slowtiger
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Post by slowtiger »

Problem exists on different levels here.

1. Colour cycling: this term usually means colour animation within 8-bit graphics, so it doesn't apply here.

2. Banding: we're working in 24bit RGB here, 8 bit per channel. This means 256 possible colour values per channel. If you spread 256 values over 256 pixel, you'll get a nice colour gradient. If you spread 256 values ofer 2560 pixel, you'll have a value change every 10 pixel, and that'Äs something you can see.

In your case you're trying to spread a short colour distance of some 15 values over a distance of several hundred pixels, so banding is unavoidable.

Solutions:
- get rid of that gradient, since it doesn't add much to the BG anyway
- use a strong noise filter on the BG - but that wouldn't fit a space BG.

Adding noise is the trick one uses in printing to avoid bending in narrow colour ramps, it "stirs up" the neighbor values so they don't form a visible line.

- Overall lack of saturation: are you sure to not use NTSC colours? Create a test file with some really strong colours and check if that looks as bland as well.

Solution: use different colours.
mankind-nil
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Post by mankind-nil »

Thank you very much for your input! Most of it makes sense.
slowtiger wrote:1. Colour cycling: this term usually means colour animation within 8-bit graphics, so it doesn't apply here.
No idea what that means!
slowtiger wrote:2. Banding: we're working in 24bit RGB here, 8 bit per channel. This means 256 possible colour values per channel. If you spread 256 values over 256 pixel, you'll get a nice colour gradient. If you spread 256 values ofer 2560 pixel, you'll have a value change every 10 pixel, and that'Äs something you can see.
Ok, I understand that. Why don't I see this kind of effect (to the same extent) when watching DVD's etc, which I understand are also compressed using H.264?
slowtiger wrote:Solutions:
- get rid of that gradient, since it doesn't add much to the BG anyway
- use a strong noise filter on the BG - but that wouldn't fit a space BG.
That makes sense - it's not supposed to be a 'space' background - it's actually more like inside a womb, so I could use some shapes as noise to break it up a bit.
slowtiger wrote:- Overall lack of saturation: are you sure to not use NTSC colours? Create a test file with some really strong colours and check if that looks as bland as well.
I have the NTSC setting in Project settings - but I thought that was only for project dimensions. Other than that I couldn't see any other NTSC settings. I had intended fairly bland colours, but the blandness seems to get worse when I compress to H.264. But there's no setting in the compression for NTSC...
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slowtiger
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Post by slowtiger »

There's an NTSC colour palette to choose from.

I think it would be best to try some colour variations and render to your final format to see how they look. Especially when you are a beginner you should do a lot more tests like that.

Watching DVDs: you still have banding, but it will mostly go unnoticed because
- films have grain, which is noise
- movement hides it
- modern DVD players process the image before projecting

You will see banding if you set the quality really low while decoding in H264, but the banding will only show along the lines of the 8x8px blocks of JPEG compression.
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Post by mankind-nil »

Ok, I understand most of that. Thank you very much for taking the time to help me out. Much appreciated!
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