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June 17th, 2006, 09:08 AM | #1 |
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Still photos with red are jittering
Hi all,
I have been working on a retrospective music video to be played off of DVD at my niece's wedding in a couple of weeks. Much of the video is either digital stills or scanned images from photos. I am having an issue with some of the photos. On just about all of the stills (digital and scanned) I am putting some movement...either a slow push in or pull out. The problem is that some of the pictures where the subject is wearing red clothing, the reds are sort of separating from the subject and jumping around. This is happening on about 4 different pictures. I've tried to narrow down the the source of the problem and from what I can see, the problem is NOT visible when playing the project timline in Vegas. Also, I DO NOT see the problem after rendering the project as an mpeg or avi and playing on Windows Media Player. The problem seems to occur when I burn the mpeg to a DVD. Since a single clip is all I need for playback at the wedding, I just used NERO to burn the DVD. I'm preparing to make the DVD with Architect 2.0, but I thought maybe someone here would know exactly what is going on. I guess if I can't rectify the problem I may have to export the project to video and play it back off of my camera. Thanks,
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Dan Eggleston - Panasonic AJ-PX800 / Panasonic AJ-PX270/Adobe CC on Mac Pro. http://www.youtube.com/pcctv1 |
June 17th, 2006, 09:19 AM | #2 |
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my first inclination would be to look at the reds on a scope and see if you've got illegal colors. Red also tends to bleed on many displays.
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Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com |
June 17th, 2006, 11:54 AM | #3 |
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If the reds are bright, compression will do funny things with them. I would recommend targeting the red portions of the image with a selective color mask and darkening the reds slightly. This should help the compression to not mangle your reds when it it converting them...do a small test first to dial it in. Reds and whites are EVIL in digital video.
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June 18th, 2006, 08:10 PM | #4 |
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Thanks Spot and Cole.
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Dan Eggleston - Panasonic AJ-PX800 / Panasonic AJ-PX270/Adobe CC on Mac Pro. http://www.youtube.com/pcctv1 |
June 19th, 2006, 10:03 AM | #5 |
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Would interlacing have anything to do with the problem?
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June 20th, 2006, 08:51 PM | #6 |
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for the digital stills, definitely try de-interlacing if they are taken from interlaced video. that can (but does not always) eliminate the pulsing effect. the other issue with the digital photographs is that they may be too high rez--the high rez pixels of digital photography don't like being compressed into video.
if you import them into photoshop and down-rez them to web quality (around 72 dpi, use the slider to choose "low" quality), you'll get rid of the pulsing....that's the absolute best solution, if you have photoshop. what is good for photos isn't always good for video. |
June 20th, 2006, 09:20 PM | #7 |
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Meryem,
You are right on with scaling back on the resolution with the digital photos. In this same project I am using some digital stills that I made black and white by desaturating the photos and brought them into Vegas without changing the resolution. The black and white photos where doing all kinds of weird vibrating and moire-ing (?). Especially in the background and with hair. I changed the height to 480 pixels and kept the ratio the same for width and they are looking much better. Perhaps I should also try them at 72 dpi? The stills are all from either a digital camera or scanned photographs so I don't think de-interlacing them will do anything, but I may also need to down-rez the scanned photos as well. They were all scanned at 300 dpi by my wife.
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Dan Eggleston - Panasonic AJ-PX800 / Panasonic AJ-PX270/Adobe CC on Mac Pro. http://www.youtube.com/pcctv1 |
June 20th, 2006, 09:28 PM | #8 |
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dan, i'm wrestling with a batch of 300dpi photos right now...when i've down-rezzed them to 72 dpi, it seems to eliminate the problem. it's always kind of a brain smash, because we always want more! higher! resolution--we do all this work and spend all this $$ to enhance resolution, and then we have to down-rez this work to get it in video. i'm not saying 72 dpi is ideal, because i haven't experimented heavily with finding the perfect balance between resolution and playback, but i just went straight to a low-quality image, and it solved the issue. no one who watches the video can tell the difference in terms of how the images present. only the videographer knows for sure!
i learned on my last DV Challenge video, made entirely with stills, that my digital rebel is actually better than my 1DsMarkII dSLR, when it comes to video because 16 megapixel images have really crushed pixels to compress to video, whereas the 8 mp camera produced better stills for video, because lower rez in the first place. less crushing of the pixels = better images. frustrating! but true! |
June 20th, 2006, 10:03 PM | #9 |
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It depends on how you are reducing the images. Aliasing can be a problem with some algorithms. Some people recommend slightly blurring sharp images before reducing them.
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July 5th, 2006, 09:23 AM | #10 |
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Hello All,
I just wanted to give an update to the problems I was having which was the subject matter of this post. Perhaps someone can gain something from it. I employed several of the remedies suggested above. One of the fixes was resizing the still photos to either 480 (height) or 720 (width). I usally always resize photos first, I don't know why I didn't do it this time and more puzzling was why I didn't find the solution myself...I'm slipping. However, the problem that was driving me the craziest was the issue of reds "jumping around" (mainly in clothing). As the sources are still images, I did take out some of the reds with photoshop. However, when I mastered to DVD-R the reds would still jump around. Well, here is my highly technical fix (sarcasm intended). As the DVD I was trying to create was going to consist of a single 10 minute project, I had chosen to create the DVD using Nero. After making a couple of new coasters, I decided to use DVD Architect instead. Problem solved. I believe the source of my problem with the reds was Nero. I also had issues with a couple of slow motion segments of my project which Architect corrected as well. I'm guessing these would be compression issues that Architect handles betther than Nero. Just wanted to pass along info in case anyone comes across a similar problem.
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Dan Eggleston - Panasonic AJ-PX800 / Panasonic AJ-PX270/Adobe CC on Mac Pro. http://www.youtube.com/pcctv1 |
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