View Full Version : Extracting Full Quality Picture from ProRes.


Loren Simons
October 3rd, 2008, 07:12 PM
So I just shot a Bar-Mitzvah, and my photographer i employed really F'ded up. So i decided it would be better than nothing to give them screen grabs from the video i took (60i) What is the best way to extract full quality, 16:9, non squished photos? I used the ProRes (HQ) codec. Thanks!

Dominik Seibold
October 4th, 2008, 01:54 AM
In quicktime-player export->(movie->picture) is a fast way. A Better way would be FCP->RGB-Balance (for retrieving above 100IRE information)->Compressor (for high-quality deinterlacing)->quicktime-player->export->(movie->picture).

Loren Simons
October 4th, 2008, 11:23 AM
thank you, but what is the RGB Balance you were talking about? I can't find it?

Noah Kadner
October 4th, 2008, 02:55 PM
Export to still images and then resize to 853x480 assuming we're talking about NTSC SD here.

Noah

Loren Simons
October 4th, 2008, 04:31 PM
We are talking about HD NTCS, but i did that and didn't get too good of results.

William Hohauser
October 4th, 2008, 09:12 PM
HD is 1080 x 1440, 72dpi. It is a limited resolution image compared to what your standard digital camera can put out. I just did a bunch of stills from a 720p ProRes project and using QuickTime Conversion / Still and they look great on the computer screen. They also kept their 16:9 ratio so I'm not sure why you are having a problem. They probably wouldn't look as good printed but they are not for that purpose.

Jo Potts
October 5th, 2008, 05:23 AM
Assuming you shot in 1080 rather than 720 and that you adjust the image to 1920x1080 to sort the aspect ratio, you'd be able to get a print res image of 6.4"x3.6" - you could probably get away with doing 6x4 from that...

George Kroonder
October 5th, 2008, 06:12 AM
it would be better than nothing to give them screen grabs from the video i took (60i)

Because you shot interlaced, individual fields only have half the resolution. Because there is a time difference between the fields you cannot easily blend them to get a "full res" frame to capture.

You could do a time consuming de-interlace using motion predictive de-interlacing and then take frame grabs, but they may never be perfect. If you go this route make an edit of couple of seconds around the spot(s) you want a frame grab from and export these to a new timeline to de-interlace. Compressor can de-interlace as Dominik suggested.

Obvious advice for future shoots it to a) take along a better photographer and b) to shoot progressive (interlaced is a delivery format i.m.h.o. except for maybe when shooting fast moving action).

George/

Shaun Roemich
October 5th, 2008, 08:29 AM
HD is 1080 x 1440, 72dpi.

Actually, the 72 dpi spec is a myth. Video does not have DPI (dots per inch), digital video is expressed in (and resolves in) pixels. Period. Not per inch, just a static dimension such as 1440 x 1080, 1920 x 1080 (AVCHD and others), 1280 x 720, 720 x 480 etc.

Please see here for more information. Vector drawing into video - help please - The Digital Video Information Network (http://www.dvinfo.net//conf/showthread.php?t=122787&highlight=72+dpi+myth)

William Hohauser
October 5th, 2008, 02:11 PM
Unlike print medias, television treats pixels on a 1 to 1 basis. DPI can be extremely confusing when you can have a graphic image with a specific pixel dimension but many different possible dpi values (150, 300, 1200, etc). When comparing video to printable photography, dpi is an important value to keep in mind. 72dpi has been considered "screen resolution" for television and computer monitors. Below 72dpi, full screen images look blocky on television monitors. Above 72dpi, images scaled down to fit television resolution can have an unnatural sharpness.

Our inquirer here can certainly use his HD images (de-interlaced in Photoshop if possible) as photo replacements but he certainly should stay within the print dimensions mentioned earlier. Smaller print dimensions will look better. Photo printers start at 300 dpi and go up.

He'll also have a hard time finding images without motion blur. A digital still camera usually runs at a higher shutter speed than a video camera.

Loren Simons
October 7th, 2008, 11:47 PM
So i should have shot this in 30p than? =(

William Hohauser
October 8th, 2008, 08:36 AM
So i should have shot this in 30p than? =(

30p can be good for stills only if the shutter is set high enough. I worked on a low, low budget music video where the producer decided (without asking) to not hire a photographer since I was shooting HD. After the shoot, I got an annoyed call. "Why is every still blurry?" I was shooting with a 1/30th shutter and the talent never stopped moving.

For decent stills the shutter should be above 1/60th. Actually 1/125th is the better minimum shutter but the motion is going to start looking odd.

Loren Simons
October 8th, 2008, 04:46 PM
alright cool thanks for the help!