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-   -   Still image - bleak? (https://www.dvinfo.net/forum/cineform-software-showcase/46637-still-image-bleak.html)

Alex Raskin June 22nd, 2005 04:54 PM

Still image - bleak?
 
Hi, I can capture a still from aspect HD-powered PPro 151 timeline.

Adding this BMP still after the video frame it was captured from.

The still photo looks bleak (less contrasty) than the original video.

That's in the timeline.

On timeline render to video, both video and still parts seem not to be different in contrast now.

Now, what's the right way to export the still frame so it looks normal *in the timeline* ?

David Newman June 22nd, 2005 05:49 PM

:) I love when someone discovers a feature. OK, here is what is happening. Apsect HD and Prospect HD allows you to optionally handle higher dynamic range RGB -- this is on by default (called video system RGB.) The problem with the standard RGB Premiere uses is it clips some valuable whites and crushes the shadows from our HDV sources.

Tech note: HDV uses YUV compression which has an official range for 16 (black) to 235 (white), in standard RGB these in-turn map to 0 and 255. However most cameras record data below 16 and more importantly that capture data above 235, any use of standard RGB will clip these off (lost forever.) Fortunately CineForm products prevent this. ;)

Back to your problem. Creating a frame of RGB data (like a BMP export) from within Premiere, you need to turn off the video systems RGB mode, otherwise your black level will be non-zero and your white below 255. This has its applications, but you are expecting standard RGB. Once the frame is extracted you can turn video system RGB on again.

Alex Raskin June 22nd, 2005 09:02 PM

Thanks David, I'll try that!

Steven Gotz June 24th, 2005 01:00 PM

I guess I don't understand. How do I turn it off? What do you mean? You lost me. Sorry.

David Newman June 24th, 2005 02:38 PM

The control is within the "Playback Settings..." window. The check box is called "Use video systems RGB." This is the high-end part of Aspect HD, is it doing things to make your video look better without you know how. :)

Alex Raskin June 24th, 2005 03:55 PM

Works like a charm in the timeline! No more contrast differences between the video and the still.

I hope it also will *render* correctly.

David Newman June 24th, 2005 04:04 PM

Yes it will render correctly. We assume all imported object into Premiere are computer graphics style RGB (cgRGB with black at 0.) There is a complex set of rules that allows Aspect HD to mix cgRGB with vsRGB segments -- all aimed at achieving the highest quality output.


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