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(MPG4) Sanyo Xacti (all models)
A compact 720p MPEG4 digital media camera recording to SD Card.


 
 
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Old March 10th, 2006, 02:15 PM   #1
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Matching a still picture to a video frame

Here is something that is probably no use to anyone here, but I needed it for my project, and it took a lot of trial and error. I needed to match a single frame of video 16:9 to a 5MP 3:4 still picture taken with the camera and have them align at 16:9 1280 x 720 pixels.

The best result I found is to crop the picture at 20,255 - 2578,1694 then resize the picture to 1280 x 720.

I save a video's still frame from Vegas.

You can see the dramatic difference in quality when you down sample from much more detail. The exposure is not quite the same in the picture and video.

http://www.gamersden.com/hd1test/chartframe.png
http://www.gamersden.com/hd1test/chartsized.jpg
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Old March 10th, 2006, 02:19 PM   #2
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Now does anyone know how to determine the FOV in degrees horizontally and vertically for a video frame with this camera?
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Old March 10th, 2006, 08:04 PM   #3
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Joseph, if you know what the "equivalent" focal length was, e.g. 38mm at wide angle, you can look up the angle of view for the equivalent 35mm lens online.

Here's a table that I just used: http://photography.about.com/library...ldef_angle.htm

Since the Sanyo wide angle attachment isn't available here yet, I found one lying around the house that is 0.45X that I was able to adapt. That works out to 17mm, or 93 degrees according to the chart, which seems right.
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Old March 10th, 2006, 08:57 PM   #4
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I kind of lost you there, but are you saying that the horizonal view angle on the lens without an attachment lens is 93 degrees? That seems very wide. That would mean if you had 4 cameras pointing in 4 directions you would have a complete 360 degree panoramic view, right?
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Old March 11th, 2006, 12:55 AM   #5
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Sorry, didn't mean to confuse. According to the table I posted, the 38mm lens on the Sanyo would take in an angle of about 50 degrees. There are probably more detailed charts out there on the web than the one I cited.

You mentioned the vertical angle. I have never seen tables for the vertical angle, but since the lens is basically round, I would assume that the vertical angle is 9/16ths of the horizontal (assuming that we are talking about HD).

The stuff about 93 degrees was the 38mm lens with a 0.45X wide angle attachment. Needless to say, there was lots of barrel distortion in the pictures.
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Old March 11th, 2006, 02:42 AM   #6
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Joseph -- I finally got around to looking at some of the clips you generously uploaded on my 60" HDTV, and wondered whether you had that opportunity? They look SO good, so much better than what I have been studying on my (excellent, 21 inch, LCD) monitor lo these many weeks. If you don't have access to a really good HDTV, I would take the HD1 to a dealer and ask to look at your clips on a demo. It really makes the whole effort worthwhile; it really is HD, if not quite the level of commercially made HDTV.

I do see that you have one problem that I have run into; I can hear the rattle of the autofocus in some shots (perhaps exaggerated by my Dolby surround sound). I have velcroed a tiny stereo mike to the top of my HD1 and plugged it into the external mike input, which solved the problem.

Now I have to find a way to show edited video on the HDTV (you can't put it back into the camera). I am exploring the TViX M5000, which one person reports works well with the original HD1 files.
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Old March 11th, 2006, 07:35 AM   #7
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Thanks Peter, 50 degrees sounds about right.

I have not been able to view any clips on an HDTV yet. It is funny how images can look better on a big screen then a small screen. I have noticed that with my Sony Z1. It looks much better on my TV then on my computer monitor. You would think it would always be the other way around...

Ironically, the primary purpose I bought this camera for is for display on a computer, and the sound track for the most part will not be used.

Good sound would be nice for vacations and such. My external mics are bigger then the camera ;) What type of mic did you use?
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Old March 11th, 2006, 11:47 AM   #8
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Everyone on the boards has been so busy looking for the bugs in this amazing camera, they have missed what "a blast" it is to use (to quote Stevesdigicams) and most have never seen the results as intended on an HDTV. Nor have I seen anyone comment on how well designed the controls and menus are -- a joy after struggling with a Sony DV's complex layered menus.

I am using an old Sony Walkman microphone, and have ordered the SP-SPSM-1 SOUND PROFESSIONALS STEREO "T" MICROPHONE at www.soundprofessionals.com. It is a "T" shaped mic, 1.5 inches wide and 1.5 inches long, and will plug right into the mic adapter that came with the camera.

Thanks again for all your work on our behalf. I want you to see your Metro shots and the Potomac pictures on a good HDTV!
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Old March 11th, 2006, 12:50 PM   #9
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Now I can't wait to check the clips out on an HDTV. I agree the menus are very well designed. Almost as good as having a bunch of buttons on the outside like the Z1. Thanks for the mic tip. I'm on the fence about selling my Z1 or keping it. For what I want to do I think this camera is actually better. I could by one or two more also to get multiple angles at a time.
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