Compression artifacts

I have a project which fills a single layer DVD with the jpg's added to the disk - I have unacceptable pixelation during crossfades and rolling credits - Is there a fix (other than reducing the size) such as DVD Studio Pro? (better codecs?)
Thanks
Steve
G5 Mac OS X (10.4.6) iDVD 6

Masterminds Karl and Lennart (… or was it Matti?) did post here loooong threads, how to avoid "jaggies" with stills in the iApps (please use forum search for threads); so, basic rules are:
* use Ken Burns effect while importing stills
* don't let iMovie render final project
* drag'n drop project's icon directly into iDVD, let iDVD do rendering
* avoid any inbetween exports in lossy codecs....
sure, Compressor/part of DVDSP has much more, elaborated features, how to set up compression.. after some years spending $$$$ and to study the manuals and learning-by-doing, you will produce much better results..

Similar Messages

Interlace problem or compression artifact?

Premiere 6.5
XP sp2
Quad-core 266
4 Gb RAM
7200 rpm SATA HDD for video projects
I am working on a volunteer project for a local museum wherein some old VHS tapes need to be digitized. The final video (probably MPEG-2) will be accessible from research computers at the museum. File size is not a big issue, but preserving as much quality (such as it is) from the 10+ year old VHS (not SVHS) tapes is essential.
So I feed the analog output from my tape deck to my Sony TVR310 camcorder for A/D conversion, then capture from there to my PC via firewire. I have tried capturing via the software that came with my Edius (a.k.a. Canopus) card, and also directly into Premiere. Same thing happens both times.
On the exported video (AVI, MPG1, MPG2) I see these wavy edges on the left and right sides of high-contrast areas. See the guy's hat in the attached image (if it ever gets outa the queu). Does this look like a compression artifact? Or is it an interlace problem? I do not see this effect when I watch the original video on my TV.
Note that Premiere reports the average data rate for the 720x480 @ 29.97 fps clip as 3600 kb/s. So when I export to MPEG I set the data rate at 5000 kb/s.
When I process and export the video in Premiere, I have "no fields" selected everywhere, and for the actual export I have selected the "de-interlace" option. Since this is for viewing on computers only, I figured that was the correct thing to do.
Edited: I should also mention that I do not see this effect in the monitor window when I scrub the clip on the timeline.
Dan Heim

The first time I tried with the capture settings reset to LFF, and then tried to export (as uncompressed AVI), specifying "no fields" in the "keyframe and rendering" dialog box, and selecting "deinterlace" in the "special processing" dialog box, I still got those artifacts.
THEN ... after searching the help file for "deinterlace" and reading all the linked pages, I tried right-clicking on the clip on the timeline, went to "video options" / "field options" and selected "always deinterlace." Had to re-render on the timeline. Then, after exporting same as before, the artifacts were finally gone.
So you were correct about it being an interlacing issue. Thanks for the insight! GSpot now reports the exported video as 29.97 frames and 0 fields.
Here's a puzzle though ... I tried the same thing with the original clip (the one captured as progressive instead of LFF) and it smoothed out as well. Perhaps Premiere is smart enough to recognize what it's getting for input, and ignores stupid commands? Whatever, this means I can use my original footage and not have to recapture 1.5 hours of video.
Dan Heim

Large .jpeg compression/artifacts?

I'm struggling with Muse's jpg compression, which I can't seem to bypass. I'm uploading very large images (2560px wide) for full-screen slideshows which have been optimized for the web in Photoshop. These images have large light backgrounds and hence Muse's jpg compression produces noticeably artifacted areas. I want to make sure it is indeed Muse that's the problem, and not Chrome. I'm previewing these locally. Thanks.

First, I have to say the delta between the screenshots is extremely small. I've had multiple people drop into my office for other reasons and none could see differences without me pointing them out using a pixel magnifying tool.
That said, here are some thoughts regarding this specific case.
Given this appears to be a photograph of black and white line art, it's a very problematic case for JPEG compression. To get a high quality result for this specific use case you'd want to start with a Camera RAW image from the camera (to avoid the camera introducing JPEG compression artifacts) and then go directly to a lossless image format such as PNG or GIF, rather than JPEG. For this specific subject matter going from Camera RAW directly to PNG/GIF would provide the best result, but at the cost of page load speed since the PNG/GIF image will likely be several times larger than a JPEG.
I expect what's occurred in this case is that the original image was a JPEG from a camera that was resized smaller and then re-encoded as JPEG.
The encoding as JPEG in the camera would introduce some artifacts but due to the very high resolution image the artifacts would be very small. Then the image was resized smaller. Resizing alters the image by using one of any number of algorithms to combine/average a set of pixels into a single pixel. The most common high quality approach is bicubic resampling. When resizing smaller this has the side effect of softening any hard edges within an image resulting in a final image that's sometimes considered ever so slightly blurry or "softer" than the original. I see this in the format.com example, in that it looks every so slightly soft or blurry compared to the PS and Muse examples. The algorithm available in PS and used by Muse when resizing smaller is bicubic sharper. This approach combines bicubic resampling with a very small amount of sharpening to counteract the blurring/softening effect of the resizing. For the specific subject matter in your image and the JPEG artifacts that were likely introduced before the image was resized, the sharping results in making the edges of the JPEG artifacts more noticeable (along making all the edges in the image crisper).
Without the URL for the webpage and the original image file (and probably the .muse file), I can only speculate on exactly what's being generated and why, but hopefully the above information is helpful.

MPEG Compression Artifacts (aka "Picture Quality Issues")

I can't stomach watching the Broncos / Browns game on NFL Network HD - the signal breaks up with small, rectangualar "compression artifacts" every 10 seconds, or every time there's a sudden movement (like the camera panning to follow the football).
This is what Comcast HD was like, and this is why I switched.
Verizon FIOS HD Picture Quality has gone down the tubes -- very much contrary to the claims of the advertising.

Glenn,
Well, I disagree, so I guess we will just have to agree to disagree.
There are going to be occasional glitches in anything, be it the TV or my car or my house or travel or elections or even my darling wife of 45 years...I have had FiOS TV for 3+ years, and over that time I have very rarely seen pixellation on any channels. I agree, tonight there is some on NFLNet, but I have had the new channels for several weeks now and this is the first time that I can remember anything more than one or two times in maybe 30 minutes. I don't see this as anything more than an unusual occurance that will probably happen again some time in the future, hopefully a long time in the future; I certainly don't see it as a trend, at least until I see it happening regularly.
Just curious, have you reported this to the FSC? I hope you and others have, otherwise Verizon may not even realize there is a problem.
Here is a link to a dslreports.com thread discussing this same issue: http://www.dslreports.com/forum/r21388668-HD-Thr-Nite-Football-on-NFLNET-HD-Pixelating
I guess TV is not just that important to me to worry about a little pixellation. I watch a lot of TV now as I am retired and have some health problems, but gee, it really is only TV.
Justin
Verizon FiOS TV, Internet, and phone
IMG 1.6.0, Build 06.89
Keller, TX
Message Edited by Justin on 11-06-2008 10:21 PM

AE CS6 imported video shows compression artifacts

So I was trying to make a video from a lossy source that plays without any compression artifacts in VLC media player or Windows Media Player, but I noticed that during preview and RAM preview that there are many compression artifacts that are visible. Rendering and playing the rendered video in both H.264 and lossless would cause the artifacts to be seen in both media players.
I tried to make a new composition from the source but it still shows these artifacts. Rendering the video in lossless would still show the artifacts.
So how do I fix this?
Here are some screenshots.
Here, you can see some very clear artifacts in preview.
This will carry over to the rendered video, no matter the render settings.
The source plays just fine.
Creating composition directly from the source yields the same artifacts.

you can't fix what is broken in the first place. The artifacts are there in the first place and any additional processing and re-compression will intensify them.
Mylenium

Compression artifacts on long form video

I have created three 1:45 min. videos on iMovie (multi-cam event shot on professional DVCAM camcorders (Sony DSR-390). When I burned to i-DVD5.1, I was disappointed with the image quality. The movies look great but there are very noticeable compression artifacts against dark backgrounds (the black area "swim" with pixel blocks) on the DVD At first, iDVD required me to use a dual-layer disc which I did and then was able on a second (seperate encode) try to use a standard single layer. The first pass, I used "best performance" preference. The second, I used "best quality." Both deliver slightly different but similarly disappointing results.
One question is: does iDVD 5.1 automatically compress in proportion to the file size/running length? The other is: is there any other tricks that can reduce the compression artifacts without having to go into more professional solutions (Compressor/DVDPro).
I have succesfully burned other long form programs but not quite this long. The most notable quality issues in previous projects were moving pixels blocks showed up on fades ins.
Any thoughts will be greatly appreciated.
Powerbook G4 167MHZ Mac OS X (10.4.5)

Hi DP,
welcome to this forum
iDVD is a consumer tool, so convenience is No1, and the main user gruop is the average "Daddy films son in the zoo" moviemaker... as me!
the specs allow up to 120min, but that pushes as said before iDVD to its limits: iDVD uses a "simple" audio codec (=huge files) and a very high bitrate with projects below 60min (8kB/Sec), that drops (dramatically) when doing longer projects.
switching "performance/quality" is to be translated with VBR/CBR...
you have two (and a half) options:
create two disks
spend $$$$ for DVDSP
all free otpions I do know (ffmpeg) don't allow setting manually bitrates for specific scenes...
silly workaround:
you could add some slight "blurr" on that specific, low key/dark scene, that reduces artifacts too... but ... well, blurrs the scene ..

Compression artifacts only in part of encode

I am going to list as best as i can.
Beautiful QT movie plays great DV-NTSC 4:3
still looks beautiful in DVDSP till I encode
After encode i get compression artifacts or what looks like old avr 3.
starting about 40 seconds in and it last for 15 seconds then it "heals" itself.
I have tried everything.
I've trashed perfs
restarted.
Printed beautiful working movie to tape, then re-diged
Presently i am trying to get compressor to work but can't figure it out. I've never needed to use it before

fcp workflow was the same as always and I have never had a problem. Dig with dv-ntsc easy set up work in blackmagic esu export using compressor making a dv-ntsc movie. I am sure I have left steps out but I do it without thinking most days. I have been using both programs since their first versions this is totally new and baffling
At this point I am willing to go to another facility to see if its in my computer or if its a footage problem
the other thing I did was to make a dvd in Idvd and I got the same result there. Which makes me think its a footage problem. Printing to tape and diging the tape in a new project in FCP and exporting a new movie should have corrected the problem. The only thing I have not tried is to re-dig the original source tapes.

Compression Artifacts in Whites!

I have a lot of movies exported from FCP as DV50 NTSC 23.98P with intentionally blown out whites. When working with the clips is FCP at "Super-White", everything is fine. But when I drop the clips into iDVD to compress, ALL of the blown out whites have grey vertical bands running through them! It looks horrible.
I've tried compressing using both the High Quality and Professional Quality settings and I get the same result. This is not a problem using iDVD 5 with the same clips. What I am doing wrong? How do I get rid of these HORRIBLE compression artifacts???

I remember seeing the effect you describe with MiniDV material years ago. But I'm not working with MiniDV, nor have I had this issue with previous versions of iDVD.
The material I'm working with was shot on HDCAM, cut in 1080P DVCPROHD, and downconverted to DVCPRO50. The DVCPRO50 version is the version that I am compressing with iDVD. And like I said, I've been doing this workflow in iDVD 5, with the same clips for the last year and have NEVER experienced a single issue with image quality or compression artifacting. So I'm confused as to what is causing it now in the newer vesion of iDVD. Software is supposed to get better with each new release, right???

Compression artifacts in validate dng output - proof attached

I have uploaded a zip file - out.dng is the output of validate dng.
https://dl.dropboxusercontent.com/u/9906333/dngs.zip
Look at the edges of the white chair - you will see classic jpeg compression artifacts.
Note that this is the default lossless jpeg conversion only.
I used the program as
dng_validate -dng out.dng <input>
I confirmed this with a build in Visual Studio using qDNGUseLibjpg=0
I would appreciate the admins looking at the provided examples.

Some suggestions and answer at least the 16 questions at the end of the Wiki article.

MPEG 2 Compression Artifacts

Hey gang, this was encoded from an MOV export (with compression markers); DVCPROHD codec. In this part of the film we tilt down from the trees and I get these strange low res frames, which follow into the next shot- a locked off interview shot. Can anyone give me some guidance as to and changes I might make in the preset (90 minutes best quality 2 pass) to help compresser deal withh this situation? THanks!
[IMG]http://i454.photobucket.com/albums/qq261/kcolber/screen-capture-1.jpg[/IMG]
[IMG]http://i454.photobucket.com/albums/qq261/kcolber/screen-capture.jpg[/IMG]
[IMG]http://i454.photobucket.com/albums/qq261/kcolber/screen-capture-3.jpg[/IMG]
[IMG]http://i454.photobucket.com/albums/qq261/kcolber/screen-capture-2.jpg[/IMG]

Can you please post all your FCP Export and Compressor settings and if you can send me 10 seconds of the critical video portion so that I can make some tests, my email is in my profile.
G.

Ideal compression settings

I'm trying to make a DVD with DVD Studio Pro 4 which features a 109 minute movie and the option of commentary over it, along with about 20-30 minutes of Special Features. Basically exactly what you might find on any Blockbuster rental DVD. However, I can't find a compression system that allows this much footage to fit on a DVD. None of the Pre-set "DVD: Best Quality 120 min" or anything even allow a 109 minute movie to fit, let alone everything else...
Is there something I am missing? Considering that Compressor is part of the same "family" as DVD Studio Pro, it seems like they ought to work better together to make the "standard" DVD...
And if there is not a pre-set setting that works for this, does anyone have any suggestions about what settings to use? I am working with an action-adventure movie using DV footage and want the best quality possible.

Commercial DVDs are often dual-layer which means that they can contain almost twice the data that will fit on a single-layer DVD-R/W. This means that commercial DVDs can place more video on a single disc or can use lower compression levels (higher bitrates) which will result in better quality.
Also, the "DVD: Best Quality 120 min" preset will hold 120 minutes of video/audio only when you select the Dolby/AC3 audio option. Otherwise, that preset when used with uncompressed PCM/AIFF audio will only be able to place about 90 minutes of combined video and audio onto a single DVD.
Given that you are apparently using Comressor 2, I'd suggest that you create a one-pass non-VBR preset at a data rate around 4Mbps (that should allow for about 140 minutes of video with compressed Dolby/AC3 audio). Next option would be to use a one-pass VBR preset with a target of 4Mbps and a maximum of perhaps 7Mbps. The reason I'm suggesting that you don't use two pass VBR is that Compressor 2 seems to have intermittent problems with its VBR output (notable digital compression artifacts in areas of high motion -- and in a highly unpredictable manner -- some areas will be okay, others will look notably degraded -- you'd have to carefully review the entire movie to make certain that there weren't problems).
Generally speaking, the one pass and particularly the two pass VBR presets should produce the best quality at any given target or average bitrate. However, you may find that Compressor 2 doesn't always deliver the expected benefits from VBR.
You may also want to try one of the bitrate calculators that are available on the internet. Here is one to try (there are others):
http://www.customflix.com/Special/AuthoringNightmares/03/BitBudget.jsp
In any case, there is really no "ideal compression setting." It depends upon the nature of your source video, the delivery mechanism, the target audience, and to some extent the skill and experience of both the videographer and the compression/DVD technician (including the software/hardware used to actually author the DVD).

Changing default jpeg compression for Web Gallery files

I have created several web galleries from both Raw and Jpeg files with Iphoto '08 that suffer from serious jpeg compression artifacts. I haven't found any way to change the compression amount to reduce the artifacts. Is there actually a way?

papasteveo:
Welcome to the Apple Discussions. There is no way in iPhoto for the user to manage the jpg compression of the web gallery photos. If the option for visitors to download the photos is selected the copy that's uploaded is compressed approximately equivalent to an Photoshop quality setting of 8 or 9 out of 12. The pixel dimensions are the same as the original unless the max dimension in the original exceeds 3054. The the file is resized to 3054 max dimension.
If the gallery is just for viewing the image is resized to 800 x 600 with additional compression.
You could manually replace the file with one that you've prepared but it would be very tedious as each file has it's own folder and the file name is changed to web.jpg (viewing only) or large.jpg (download). You would have to rename each file to be uploaded to the new name and make sure it's placed in the correct folder.
Do you Twango?
TIP: For insurance against the iPhoto database corruption that many users have experienced I recommend making a backup copy of the Library6.iPhoto database file and keep it current. If problems crop up where iPhoto suddenly can't see any photos or thinks there are no photos in the library, replacing the working Library6.iPhoto file with the backup will often get the library back. By keeping it current I mean backup after each import and/or any serious editing or work on books, slideshows, calendars, cards, etc. That insures that if a problem pops up and you do need to replace the database file, you'll retain all those efforts. It doesn't take long to make the backup and it's good insurance.
I've created an Automator workflow application (requires Tiger), iPhoto dB File Backup, that will copy the selected Library6.iPhoto file from your iPhoto Library folder to the Pictures folder, replacing any previous version of it. It's compatible with iPhoto 08 libraries. iPhoto does not have to be closed to run the application, just idle. You can download it at Toad's Cellar. Be sure to read the Read Me pdf file.

What is the best compression scheme?

Material shot on HD, downconverted to DV, edited in FCP and now I want to put in onto a DVD. About an hour of material.
What is the best compression scheme? So far testing seems to be export as 10 bit uncompressed and let DVD SP compress it but it's still not great. Lots of compression artifacts in the dark backgrounds.

Also place compression markers at those points in your presentation, where you have sudden scene changes but not because you made an edit at that point. FCP automatically places compression markers at edit points during the edit process in FCP. Then when you export out of FCP, be sure to use the DVD SP Markers export option, (Export as Quicktime Movie) this will then include any compression and chapter markers you've placed in FCP, which will be used by Compressor, during the encoding process to the .m2v file, which helps avoid artifacting on sudden scene changes.
The chapter markers will then be embeded in the .m2v file and used by DVD SP when imported. Personally, I use BitVice, (as my m2v encoder) but compressor works well as well.

Compressing movies for web use

I have just finished a movie which is now about 6 gb. I do not have a .mac or iweb account. I am looking to upload this on youtube or myspace. However, it needs to be down to about 100 mb.
How can I convert this to a wv format or anything of lower quality??
thanks.

III. hand for iSquint...
have a look in its options:
1) select "for TV"… that generates an mpeg4 ("iPod" generates h264)
2) push Quality slider to the far right, max... click expert options (my user interface is German, correct?)
3) youtube.com requires 320x240
4) bitrate & fps: you reduce the final file size with that; and you set the quality.. NTSC has 30fps, but 15fps cuts the size in half... but movements aren't as smooth...
for publishing that files on your own site, 500-700 kB/s result excellent quality, 200kB/s still acceptable 8depends on content & your personal threshhold)...
my experience with youtube.com: it adds ALLWAYS compression artifacts... no sense to go beyond 300-400 kB/sec
5) you should choose deinterlace
and you can spare some MB by reducing audio quality, I do use 60kB/sec, 22050HZ, mono...
to give you an impression of resulting quality, watch both demo movies on my HowDidYouDoTHAT website (some tricks with iMovie...), in the section Filmstrip ... my demos are .mac hosted, the YouTube demo was uploaded and is on my website embedded...
30minutes... long movie.. for webuse...

Weird JPG compression question

Hi,
I am using I am using Windows 7 x64. My camera (Nikon D700) automatically saves copyright data with my name and phone number. I am editing thoose JPEG files from Photoshop CS5 and save them on a HDD with compration ratio 12. For example:
http://dl.dropbox.com/u/26109102/TEST1.jpg
As you can see file size is about 4.67 MB
However, when I right click to file in windows 7 and choose properties and than remove my phone number, file size dramatically reduce at 1.45 MB. Here is a file:
http://dl.dropbox.com/u/26109102/TEST1%20-%20just%20remove%20phone%20number.jpg
So what is the reason of that? Whan I compare both files I can not see the difference in compression. Could you also check it please. Is it a kind of bug?
Thanks in advance.
Koray

The original compression ratio is 66MB/4.5MB = 15 (mental arithmetic).
The final compression ratio is about 66MB/1,45MB = 45.
Such a high compression should be clearly visible, mainly at edges.
But the two images are almost identical. Use image calculation > subtract
and analyze the resulting alpha channel.
a) by histogram
b) by an extremely steep curve.
There are differences, but these are very small.
In my opinion the question is not yet answered. Or is the answer "Microsoft
has improved the standard JPEG compression by factor three"?
I'm using older software, therefore I can't reproduce the OP's tests.
Best regards --Gernot Hoffmann
Edit:
Compression by factor 45 for arbitrary images would deliver really bad results.
The situation here is slightly less critical, because large parts of the image are
almost uniform.
But even if we assume an effective compression by factor 25 for the image parts
with details - the compression artifacts should be visible, in my opinion.
But the aren't. Here we need some clarification.
Message was edited by: Gernot Hoffmann

Compression artifacts

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