Still Image Visual Shift

[Mike Truly]

This was discussed a bit on the old forum but I don't recall any resolution.

I frequently use the Still Image Exporter to generate a still off the timeline and then place that still abutting the video clip(s) that it was generated from. It is very easy to tell that the TGA still I generate does not precisely match the video clip.

Let's say the video clip has a Color Correction applied. When I generate the still, I leave the CC turned on and so, in theory, the new still has that CC applied to it. But when it's then placed on the timeline next to the video clip, it doesn't match... exactly.

I then tried turning the CC off on the video clip and generating the still and it doesn't match either.

Is there any way to get a perfectly matching still? Is one format better than another for matching (I prefer TGAs). I'm guessing that the reason it doesn't match is that the video clip is YUV and the still is RGB.

Thanks!

[Vaughan Wood]

Hi Mike,

I use this technique a lot to close every wedding video I do, and I get a perfect match.

Don't know if it matters, but I use .bmps and in advanced settings it's set on odd field and motion only filtering.

Cheers Vaughan

[antonsvideo]

what change do you notice on waveform/vector?

different black level?
different white level?
different color saturation?

[upapi]

Hi,

did you try Topaz Moment? It's incredible and exceeds all my expectations on stillimages.

Uli

[Mike Truly]

Anton,

It appears, all of the above. I've attached two screengrabs of the WV. One showing the last frame of the video clip and the other showing the resulting TGA made from that last frame. There is a definite shift in all values between the two. (It may be hard to see when looking at the two images but is easy to see when stepping between frames... both in the preview and WV).

I also have a two frame HQ 1280x720 video clip that shows the problem. The first frame is the last frame of the video clip (with a single ColorWheel CC applied) and the second frame is the still.

http://www.trulymedia.com/issues/image_shift_video_clip.zip

Thanks!

[Mike Truly]

Uli,

Thanks for the ideas. The Topaz Moment looks very interesting but I'm not sure how this fits into the Edius workflow. Since I will frequently be wanting to create a still that not only contains the video but also the effect applied to the video on the Edius timeline (such as CC) that I would need to render out a single frame HQ file (with CC) from the timeline, then use Topaz Moment to capture that one frame from the video, save as TGA, then import that TGA into Edius and drop on the timeline. Is this how you use it with Edius?

Also, the sample images shown look like they are greatly improved from the originals. While this is nice... I want the image I get to exactly match the HQ clip (warts and all) so I can use it on the timeline next to the HQ clip and have it match precisely. That software looks like it will make it look better, and different.

Thanks!

[antonsvideo]

Hi Mike

I see your problem with the avi you provided, must be an NTSC issue

to overcome, try this:

mark in and out of the frame you want to be a still and choose print to file, choose Canopus HQ AVI

now place the 1 frame avi on timeline and apply speed change 1%, then copy/paste this clip as many times you need

[upapi]

Hi Mike,

I think Antons solution fits your needs the best. Until now I uses Topaz Moments to get Stillimages from Clips. Quality is much better than producing images by Ctrl+T in Edius.

Uli

[Mike Truly]

Anton,

I will try this... thanks!

[Mike Truly]

Uli,

I will try Anton's idea. But I notice in the helpfile for the Topaz Moment software that there is a switch to just do a 'Raw Capture'... no enhancement. This might provide a matching still frame as well.

But I'm wondering if this difference problem is somehow related to the fact that HQ files are YUV and that the still image is RGB. In which case, the still will always be different. I will have to do some experiments.

Thanks!

[Mike Truly]

Scuze me while I beat this dead horse.

I really would like the Still export from Edius to be fixed (or at least improved) to correct this problem. Yes, the 'make an HQ AVI instead of a still' method works... but it's a huge hassle compared to making a still that works in the first place.

When I make a still (such as a TGA or other bitmap), I want it to match the video frame from which it came precisely. That means no brightness shift, etc.

I suspect this is being caused during the translation from a YUV format (which I think the HQ file is) to an RGB format. If it can't make a precise duplicate of the video frame, it should at least try to make some internal comparisons between the two images to make the still match the video better or give the user the option to use this modification.

Right now, I am creating TGA stills from HQs on the timeline and there is a large shift in brightness when passing over the cut point which makes these stills unuseable.

Thanks!

[Mike Truly]

One thing I think I may have noticed may be a bug of some kind.

Originally on my current project, I set this project up as SD 4x3. In this project, I created TGA stills from the HQs on the timeline and they matched perfectly... no brightness shift when the resulting stills were placed on the timeline next to the original HQ clips.

Then I created an HD 720p project by changing the settings of the original project and started to replace all the clips with the HD versions. It was at this point that I started to make HD TGA stills to replace the SD stills. These new HD stills have the visual brightness shift.

SD version of project: no brightness shift in TGA stills.
HD version of project: noticable brightness shift in TGA stills.

Then I just now realized that the previous project problem that started this thread a number of weeks ago, was also a 720p project.

I could be wrong but it seems like there is a pattern here having to do with the 720p project generating brightness shifted stills.

Thanks!

[antonsvideo]

you can do it without export to avi as well

simply place cursor to frame that you wish to freeze and press C to cut, advance cursor one frame and press C again, now apply Alt+E 1%

[RandyD]

Uli,


But I'm wondering if this difference problem is somehow related to the fact that HQ files are YUV and that the still image is RGB. In which case, the still will always be different. I will have to do some experiments.

Thanks!

My bet is you are dead on it. You will also see color differences when you go from a still to an .avi using Imaginate. If you look in photoshop it now offers HDTV 709 as a color space you can convert a still to...and the difference is very noticable. Try converting the still to that colorspace in PS then see how it looks next to the clip.

[Mike Truly]

Anton,

Thanks... I will give this method a try. What is the second cut for? Oh, I think I get it... the second cut is if the desired frame is in the middle of other frames?

In my case, most of the stills are either the beginning or end of the clip so I think I only need one cut.

Thanks again.