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Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable

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Bill McFadden
Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 2:48:15 am

Hello Everyone,

I am having some problems correctly rendering some HD footage into a web page banner that needs to be 832 x 288 pixels for my site with Sony Vegas Pro 11.0. I should say that most of the rendered footage looks pretty good overall, but in places it just doesn't look polished because of the blemishes that I'll describe below.

The footage is a mixture of still shots that are stock from my digital Canon camera. It shoots at 12 Megapixels, at 4000 x 3000 pixels at 300 dpi. The video is full HD video at 1920 x 1080 shot with a Canon AX-10 at 24 mbps (AVCHD format, shows as MTS on the HD), mixed with a few titles, some background music, etc. Some of the still shots are animated slightly, to add interest to the shots, as opposed to appearing as a flat, still image.

I have tried several settings for my renders, including full size HD (1920 x 1080), down to the size I posted above. The problem is, that in every case, there appears to be some kind of shimmering effect that appears at random places in the video... sometimes on roof tiles or windows, etc., or shutters, etc. At other times... sometimes in the same video... there will be areas with clumps of large pixels clustered in a group... sometimes on walls, or areas of the sky, etc.... which appear for a few moments, and then disappear. much more rare, is the appearance of a larger area of pixelated blotches that flash onto the screen quickly, and then disappear just as fast, but are very distracting and take away from the overall quality.

No matter what settings I try, I cannot seem to get rid of these issues, and I find them to be unacceptable when I'm trying to use these rendered videos for business, and ultimately to attract customers. Can anyone possibly shed some light on what I might be doing wrong here? I've seen video used on other web site banners that looks flawless, and plays very smoothly. This is what I would like to achieve for my stuff too, but it just isn't happening. :(

Ultimately, I want my rendered video to look great when it plays on smart cell phones and tablets, as well as on You Tube, Vimeo, etc., when rendered in 1080p AND 720p. Any suggestions for improvement will be greatly appreciated!

My computer is an Intel i7-k2600 running Windows 7, Service Pack 1, at 3.40 GHz, with 12 Gigs of RAM. My video card is an Nvidia GeForce GTX 570 with 1280 Mb of GDDR5 memory.

I've added the embed code from You Tube for one of my videos. I noticed that it displays at 560x315, not the 720p Sony Tablet setting, which renders at 1280x720.

Thank you for all your help!
Bill


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John Rofrano
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 4:44:29 am

[Bill McFadden] "The footage is a mixture of still shots that are stock from my digital Canon camera. It shoots at 12 Megapixels, at 4000 x 3000 pixels at 300 dpi. "
That's your problem right there. Vegas Pro is not Photoshop. It is not designed to rescale 12 megapixel images into less than 2 megapixels that it needs for HD. Help it out by residing your images to 1920x1080 before you use them in your project and a lot of that shimmering will go away.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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Bill McFadden
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 1:22:16 pm

Hey John,

Thank you for your response. I appreciate the help, and obviously need it.

However, I'm a little bit confused still. I resized a few images, and am getting ready to pull them into Vegas and re-render to see what happens. But, I took a look at some of the file data on those images, before and after re-sizing them, and this is what I found there.

As I mentioned previously, the image resolution (by default) is 4000x3000. My image editor reports these images as 180 dpi, not the 300 dpi, I thought they were, and shows them to be 24 bit depth. As such, before resizing, the images are 2.94 MB, and Windows Explorer reports them as 3,017 KB. After resize, they are shown to be 1920x1440 at 300 dpi (the editor is saving them as this dpi), still 24 bit depth and 633 KB in size.

I loaded up a few frames of stills and video, using the newly resized images, and I'm still getting some of that shimmer effect, but not as much, it seems. Still not quite what I'm hoping to get out of it, but definitely improved.

This time, I rendered in Sony Tablet 720p, which works well for viewing on tablets and cell phones, which is one of the goals I am trying to accomplish.

I also rendered to my other target file, a video header for a web page banner, using the same template, but adding a custom size of 832x304. The shimmering rooftops were more present than ever before, while the still from inside the home looked just fine.

Very frustrating, but still hoping for a solution that works in both cases.

Thank you John, and if you notice anything else I'm missing, please do share!


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Russ Froze
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 4:56:35 pm

It couldn't per chance be a moire pattern introduced by the camera(s)?
http://photo.stackexchange.com/questions/11909/what-is-moir%C3%A9-how-can-w...

Russ Froze


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Bill McFadden
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 9:43:14 pm

Hi Russ,

I don't think so... but am not absolutely certain. There doesn't appear to be any weirdness to the actual still image. However, I have noticed that the edges of roof tiles, shingles, or edges of screens, or metallic items, etc., is where I see this occurring most.


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John Rofrano
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 8:05:49 pm

Are you adding motion to the images? Are you cropping to the project aspect? You might have to add a bit of a vertical blur if you have really fine lines.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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Bill McFadden
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 9:57:28 pm

Hi John,

Yes, I am adding some very slight motion to the still images to add interest.

When I resized the images, as you suggested earlier, they resized from 4000x3000 to 1920x1440. So, when I import them into Sony Vegas Pro 11.0 & drop them on the timeline and select Widescreen, I see a portion of the image selected in the Preview window. Of course, what I see there is only a part of the image, vertically speaking. But, I like to add more than a simple up and down movement to the image, so I resize the image a little bit smaller in my starting keyframe, and move the image up and to the right, or some variation thereof, in my last keyframe. Total time for the image is approximately 4-5 seconds, with a 1 second crossfade to the next image.

There ARE some fine lines in the image, which are usually the edges of roof tiles or shingles, etc., as I explained to Russ in the previous post. This is where I see the weird shimmering effect the most. It also appears on metallic objects, like the edges of window screens, or screen doors, and sometimes on the blades grass in the lawn, or on the edges of glass in an opening door, etc. (I sometimes have a shot of a door opening door, though that is a video image and not a still).

I will give the vertical blur a try, but will that cause my images to lose the sharpness of image I am craving? :)

Thanks again for your help on this. It is much appreciated!!!


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Bill McFadden
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 10:12:34 pm

John,

I just noticed I am getting some of that shimmering effect on the white window pane frames in some of the animated images too, but not on all of them.

Is there some way to post a small piece of the rendered video so you and others can see what is happening here? May be helpful in some way perhaps.

Thanks!


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Bill McFadden
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 29, 2014 at 10:19:15 pm

When you ask, "are you cropping the project aspect", do you mean the outputted render size? For example, my video is 1920x1080, my images (resized) are now 1920x1440 (or close to that... I had to rotate some of them slightly to straighten them, and then re-crop to the final saved image).

I am then rendering to more than one size for different applications. For You Tube, I'm rendering to Sony Tablet 720p and Sony Tablet 1080p (still trying to decide which one I want to use). For my web banner, I have a cell that is 832 pixels wide to place the rendered video in. I have tried a height of 288 and 304, but they don't look right to me. I used multiples of 16, but am relatively new to this stuff, so not sure what to use yet.


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Russ Froze
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 30, 2014 at 1:42:19 am
Last Edited By Russ Froze on Nov 30, 2014 at 1:58:40 am

Yes that droves me nuts or it used to. And yes that is moire which does not become apparent until there is movement in the image. Do some pixel peeping and likely you will see odd artifacts in the still image at intersecting lines in repeating patterns.

To combat this issue one might add a slight vertical blur as John has suggested.

Also 1440 x 1080 is a trick invented by clever engineers to cut down the data rate and file size so as to allow tape and SD cards to handle data. The pixel aspect ratio is not exactly square. The same formula was used on DV footage for both square (TV) and 16 x 9 (widescreen). Pesky engineers fooled us again like they did with interlacing. The famous 720 x 480 pixel (TV) which had an aspect ratio of 0.9091 or 16 x 9 widescreen aspect ratio of 1.2121.

The 1440 x 1080 is even more out of square at a whopping 1.3333 pixel aspect ratio. The math is incredible and as you might know anything divided by 1/3 can not be reconstructed. There is always a shortfall or excess. Pixels need to be mathematically square or the leftovers will case problems. Now compound matters by adding rotation or skew. Just imagine the formula needed to work it all out with pencil and paper.

I have been creating banners via video editor since Macromedia created the flv codec. Before that it was flash animations only for the web. At that time is was explained to me that whatever the dimension the pixels need to be square. If there is half a pixel or two left over they have to be crammed in somewhere. Use even numbered font size, stay away from odd numbered fonts like 11 or 13 and lo and behold your flash animations will come out crisp and clear.

The same holds true for digital video, the pixels must be square and divisible by 2 in order to attain a crisp clear image.

I understand it's a complex issue and will garner a great deal of debate but, that is what has worked for me.
Russ Froze


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John Rofrano
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Nov 30, 2014 at 1:36:32 pm

[Bill McFadden] "Is there some way to post a small piece of the rendered video so you and others can see what is happening here? May be helpful in some way perhaps."
No need. I know exactly what you are seeing. I do lots of photo montages and experience this a lot.

Do you have your project set up as interlaced? If so, what you are seeing are details that are smaller than 2 scan lines (i.e., just 1 scan line in height). What interlacing does is display odd scan lines and then even scan lines. If there is a detail that is only 1 scan high, it will appear to flicker on and off as the odd/even scan lines display. This is why I said to add a slight vertical blur... to smear the details over more than one scan line. ;-)
[Bill McFadden] "When you ask, "are you cropping the project aspect", do you mean the outputted render size? "
Yes, right-click on the image in Pan/Crop and select Match Output Aspect.
[Bill McFadden] "I am then rendering to more than one size for different applications. For You Tube, I'm rendering to Sony Tablet 720p and Sony Tablet 1080p (still trying to decide which one I want to use). For my web banner, I have a cell that is 832 pixels wide to place the rendered video in."
All of those delivery formats are progressive. I would recommend that you set your project properties to be progressive. This should solve the interlacing artifacts that you are seeing.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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Stephen Mann
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Dec 12, 2014 at 12:39:09 am

DPI is a printing term and means nothing in video.

Steve Mann
MannMade Digital Video
http://www.mmdv.com


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John Rofrano
Re: Shimmering effect & pixelation makes rendered video look unprofessional & unacceptable
on Dec 12, 2014 at 2:17:10 am

[Stephen Mann] "DPI is a printing term and means nothing in video."
True, but it does mean something in an image editor so it's an important distinction to bring up. If you are using Pixels as the measurement, then most image editors will ignore DPI. If, however, you are using Inches or Millimeters, then most image editor will change the Pixels to match the DPI. So just be careful. Always work in Pixels for video.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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