Image Quality on Pan & Zoom

[ctheiss]

Running x3, I inserted a large image of a wedding into a video. The idea is to start zoomed right into the faces of the bride and groom, and then slowly zoom out to include the families. Now, the image is large enough (6144 x 4088) that zooming that far in should still look great, but it doesn't. It looks blurry. It's almost as if the image was resized to fit the video, and then I'm zooming into this smaller version.

This isn't a preview issue; even the final rendered video looks blurry. Also, turning off the "image flicker prevention" option did not help.

Any ideas would be greatly appreciated!
Corey

[BrianCee]

It's almost as if the image was resized to fit the video, and then I'm zooming into this smaller version.

Unfortunately that is exactly what is happening - TV screens only have so many pixels in them and although you may start with a high res multi mega pixel image it has to be converted to a standard video format when you put it into a video editor timeline in order to be viewed on a TV Screen.

You haven't told us which country you are in (PAL/NTSC) or what the video properties are standard/HD etc. - so if I take a worse case (NTSC/standard) then you picture will be reduced to 720 x 480 pixels - try putting an image that size in Picassa and then zoom into 1/20th of the image and see what that looks like.

Obviously the problem will be considerably lessened in higher quality videos with higher pixel numbers - but I think the problem is that you are just over zooming on a video image.

[ctheiss]

Thank you for the quick reply! I realize the limitation of the number of pixels on my screen, but this problem could nonetheless be solved without making the picture blurry.

Situation #1 (I think this is what is happening)
x3 shrinks my 10Mp picture to 1Mp (for example) so it fits the screen
I zoom way into this 1Mp picture, and it look blurry

Situation #2 (Blurry avoidance)
x3 shrinks my 10Mp picture to 1Mp for display on the screen, but keeps the 10Mp around
I zoom way into the picture, but it doesn't look blurry because it used the original 10Mp picture to do the zoom

My video output is 16:9 mp4 in 1080p. Given that my zoom is to about 1/6 the width, that computes to a 200% zoom of the original picture (which is 6144 across), which really shouldn't be too blurry.

[BrianCee]

Unfortunately Situation#1 is what is happening - there is no option in VideoStudio to retain the 10Mp picture 'in the background'

[ctheiss]

As an experiment, I have tried 720p as output, and carefully selected the zoom level to not exceed 100% of the original picture. The result remains blurry.

I then split the sequence into 4 groups, and imported 4 different zooms of the picture. Finally, I set up the pan & zoom so that one zoom flows into the next. This solved my blurry problem, but each of the transitions are a little off and will probably require a lot of work to get bang on, especially since the pan & zoom tool doesn't allow you to set a specific offset (please correct me if I'm wrong about this).

Is there a setting somewhere so that I can avoid having to do manual interpolation?

[ctheiss]

Hi Brian,

Sorry our posts are a little off-kilter. Based on your last post, does that mean that whenever I use pan & zoom to zoom into the picture, I'm losing quality compared to the original image? How can I set x3 so that it "pre-shrinks" my images as little as possible upon import? Thanks,
Corey

[sergeyso]

Hi. I'm interested, could you please clarify - did you try Picture In Picture from NewBlue which is in X3?
I've checked in DV PAL project with a large image:
1) Add the image 3888x2592 to overlay track
2) In alignment options select Original Size - so the image will be extended over the video frame and that will be the working area for Picture in Picture
3) Add Picture In Picture and adjust it - on opened dialog I was able to zoom and move over the picture.

For my eyes the result looks ok. I've just noticed that after making the Size relatively small (10% or so) - the quality of image is bad, probably because of PiP algorithms, so you need to balance original size and reduction.
Or missed something?

[ctheiss]

@sergeyso

Thank you for the reply!

It doesn't look like the PiP obeys the pan & zoom that I set up, or has the ability to have its own pan & zoom. However, if you're not interested in this feature, it does indeed look like you can zoom into the picture and benefit from the original resolution.

[ctheiss]

Well, I just spent about an hour chopping up the picture to various zoom levels and trying to get them to flow nicely from one to the other. I even worked out all the math, but the inability of specifying exact offsets in the pan & zoom tool made it impossible to get the it bang on. I tried adding really short crossfades to hide the sudden "jerk" by a pixel or two during transition, but it still looked like a mistake.

So, in the end, all I could do was increase the crossfade length to at least make it look purposeful and artistic.

Maybe x4 will fix this deficiency. I am happy to say, however, that this was the only effect I couldn't quite accomplish in my project... everything else is exactly as envisioned and looks fantastic. The other work-arounds I had to make were lack of transition effects on text overlays, and no logarithmic interpolation of zooms.