Film to Mindv transfer question

Post by **mattias** » Mon Feb 10, 2003 7:06 pm

interesting. this suggests two things:

your camera does indeed output to svideo before compressing, since the sample grabbed from tape is blockier than the direct capture.

your camera does a better job at digital to analog conversion than your software codec, since from dv tape through analog capture is sharper than the firewire transfer. i think there must be something wrong with your quicktime codec in this case. my quicktime renders and displays everything razor sharp when set to high quality. are you *positive* that the high quality bit was set?

/matt

Post by **S8 Booster** » Mon Feb 10, 2003 7:50 pm

mattias wrote:i are you *positive* that the high quality bit was set?

/matt

No I can not verify it as of yet. The frame was exported via iMovie from which I have no known control over the image quality.

However, I will import the DV clip again, open it in QTP6 and set it to best quality and export a frame to compare and post it. To follow later.

R

Post by **S8 Booster** » Mon Feb 10, 2003 10:59 pm

Rather than possibly cause any detoriation in image quality I just posted the DV clip as is so you can do what you like with it. This is the DV tape file.

The shot was done with a sligtly supported cam not a tripod. Steady shot off to avoid controlled blur. I hoped for a few good frames which I got. Pick one.

File: ftp://ftp.filmshooting.com/upload/video ... pp%2002.dv 18.8 mb / 5,5 sec.

R

Post by **mattias** » Tue Feb 11, 2003 11:53 am

S8 Booster wrote:Rather than possibly cause any detoriation in image quality I just posted the DV clip as is so you can do what you like with it.

well, seems like you did indeed forget the high quality bit again. :-)

here's what i got from that dv file you posted:

when you created the jpeg, did you do a screen dump or what? quicktime should always use the high quality version when you convert to another format, since the low quality version is for playback *only*. what i did was i apple+c copied the frame from quicktime player, where it indeed looked pretty awful, and apple+v paster it into a photoshop document, where all the quality showed. the same thing should happen when you "export as still image" from qt player...

/matt

Post by **S8 Booster** » Tue Feb 11, 2003 12:15 pm

No, this time I just uploaded the raw DV file from the cam without going through the QTP so you could work with the original file. I am sure your process is correct but it brings up another interesting question:

It is no doubt that the DV format recovers at playback from normal video recording compared to what the default still images provide. My DV export was always made from the iMovie - no screen dump.

However, will it also "recover" when the single frame capture method is used like the WP?

R

Post by **mattias** » Tue Feb 11, 2003 12:26 pm

S8 Booster wrote:No, this time I just uploaded the raw DV file from the cam without going through the QTP so you could work with the original file.

yeah, i know i did it correctly and i know that was the raw dv file. i'm just trying to figure out why my result looks so much better than yours. :-) if you exported to jpeg from imovie i'm really puzzled, but you exported as pict, right? how did you convert to jpeg?

However, will it also "recover" when the single frame capture method is used like the WP?

that depends on the software. a program like dodcap will just save the compressed frames to disk which will eliminate any problems, but with programs that transcode the material you have to be careful. fcp versions prior to 3 for example do not use the full quality when you capture from dv to pjpeg, since there's simply no time for it if you don't have the altivec optimized "offline" codec that fcp3 uses...

/matt

Post by **S8 Booster** » Tue Feb 11, 2003 7:36 pm

The DV image was exported from iMovie as a PICT file with highest quality setting. No further processing executed.

When it comes to the QT player there is definately something wrong with the image export control. Whatever format I choose it goes PICT. This is independantly of the film quality setting high or low. The image always comes out low res compared to yours. I can set the clip to HQ and save and it will give better motion images but it makes no difference to the still images exported.

R

Post by **crimsonson** » Tue Feb 11, 2003 7:52 pm

make sure you are exporting both fields and not just one [I barely used iMovie, so I am unsure of its full capabilities].

Post by **mattias** » Tue Feb 11, 2003 8:25 pm

S8 Booster wrote:The DV image was exported from iMovie as a PICT file with highest quality setting. No further processing executed.

then how did they become jpegs? :-) i haven't looked at the original pict files, only the inline jpegs.

and you're still somewhat confusing the high quality bit with high quality compression. the quality level you use for export doesn't matter for the viewing quality if the high quality box isn't checked...

/matt

Post by **S8 Booster** » Tue Feb 11, 2003 9:59 pm

mattias:
--------------------------------------------------------

then how did they become jpegs? i haven't looked at the original pict files, only the inline jpegs.

The full frame captures (No 2, 3, and 4) posted first were original 1 stage export from Adobe Premiere Non Compressed captured files to .PICTs.

No 1 was captured from the cams DV file exported to iMovie via Firewire and the full frame was exported as a .PICT file as posted in a one stage operation.

The reason for using the .PICT files is that my AP exports .PICT single frames only and to unifom the files I exported the Cam DV file from iMovie as a .PICT file as well.

The .JPEG file inlines were out-takes from the full frame .PICT files posted first, opened in Graphic Converter and the details/inlines were cut and saved as .jpgs for everyone could see a possible difference, The main structures remained true.

The full frame .PICTs posted first are all "clean" original frame export samples, 1 stage export captured with/from Adobe Premiere, no format change from frame capture expect frame export to .PICT format.

crimsonson

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make sure you are exporting both fields and not just one [I barely used iMovie, so I am unsure of its full capabilities].

The frame export from iMovie is either .JPG or .PICT format with no quality options on frame export, at least for .PICT files on my system.

For moving images (video track) there is a optional high quality setting and "single frame" setting. The high quality video track setting improves moving image quality a lot. The optional single frame (actually 1 field I guess) setting drops image quality noticably. I never use it.

R

Post by **S8 Booster** » Tue Feb 11, 2003 11:37 pm

mattias wrote: what i did was i apple+c copied the frame from quicktime player, where it indeed looked pretty awful, and apple+v paster it into a photoshop document, where all the quality showed. the same thing should happen when you "export as still image" from qt player...

/matt

Just have to add that your posted image yields an outstanding image quality and looks better than anything I posted from my Machines. Interesting.

I will look further into this.

R

Post by **mattias** » Wed Feb 12, 2003 11:06 am

S8 Booster wrote:The .JPEG file inlines were out-takes from the full frame .PICT files posted first, opened in Graphic Converter and the details/inlines were cut and saved as .jpgs

this must be where something went wrong. i used photoshop, which as you can see preserved the image quality a lot better. maybe gc isn't aware of the "high quality" bit or something. the qt api is a mess, believe me. ;-)

/matt

Post by **S8 Booster** » Wed Feb 12, 2003 11:45 am

Hmm.., the PICT files I posted first is as is if I open and enlarge 2-3x (not scaling) them in any Graphics Viewer.

I tried your method too by copying the frame from QTP and past to Adobe Photoshop 5.5 LE but did not get any improvement and nothing like your result so there is a difference in our systems that I can not figure out.

Could be an additinal plugin in your PS? or another plugin in your QT via FCP?
Which version of PS do you use?

R

Post by **mattias** » Wed Feb 12, 2003 11:57 am

S8 Booster wrote:I tried your method too by copying the frame from QTP to Adobe Photoshop 5.5 LE but did not get any improvement and nothing like your result

how did you copy? screendump or a regular copy? did you copy from the pict or from the dv file? i couldn't get it to work properly from a pict, although that too benefitted a lot from checking the high quality box...

here's something to remember for the future: if you get results suggesting that the dv format isn't up to par for something, check everything again and even if you don't find a problem don't trust your results. there are very few situations where dv doesn't provide good enough quality.

/matt

Post by **S8 Booster** » Wed Feb 12, 2003 12:18 pm

I did it exatly the same way you did which is a procedure I often use . No Screen dump. I am *not*8) the one NOT to exploit any possibility or give up at the first resistor either. :!:

However, I do not doubt that your system/setup works as you describe and works correctly I just can not as of yet figure out the difference but this is not a problem to me as the motion part works well and achieves the results required in HQ DV mode. There is however, an known error in my QTP image export function because whatever format I choose to export I get .PICT format so there might be something in connection to this that prevents the HQ rendering. Very unMAC like problem more like PC.

.

That said the method that you use works well in image processing and is very interesting for using HQ stills from DV tape, not needed to use the still function/memory stick because your result looks as good as to me.

R