Suspicious Specs for DVD menu

[steviespin]

Hi there

i am prepping a series of graphics for a DVD menu. I supplied tiffs at 720x540.

When we got a check disk, the graphics were blurry and i was then asked to redo all the graphics at 300 dpi.

This doesnt make any sense to me, but I havent done many dvd menus so i wanted to put the question out there.

Is there any possible reason for this?

S

[poisondeathray]

Perhaps you could provide more information on what programs were used to create the DVD menu?

[Cornucopia]

Firstoff, anybody that uses "DPI" with video is either using their terminology sloppily or they honestly don't know what they're doing.

DPI is a print/scanner scale. Video just uses pixels. If you want to "equate" usual video resolution to a print scale, you could say it has 72 dpi, but strictly speaking it doesn't apply.

Now with that behind us, your 720x540 image is fine if it were composed for a Square pixel display device. Non-HD TV however, ISN'T a squarepixel device. To get a work test copy that is exactly what you were hoping for, you should have pre-composed it for the proper resolution, or should have done a final crop/resize to the proper resolution. I'm assuming NTSC land here, so it should have been 720x480 (or alternately, 704x480). It may make things blurry, but it'll be alot less blurry if you do it correctly with the correct software and algorithms rather than rely on somebody else who may or maynot know the optimal method.

You also should know all about the huge differences in quality to be expected between progressive vs. interlaced, and RGB vs. NTSC monitors.

Good luck,

Scott

[lordsmurf]

Somebody is a moron, and it's not you.

Indeed, DPI is a printer measurement. DVD menu screens are to be done at 72dpi (the standard "print size" for onscreen-only images). Most DVD authoring software accepts (AND PREFERS!) 720x540 still images for a "full screen" (4:3) menu. Only video clips (for motion menu) should be 720x480.

The problem is this person applied anti-aliasing filters to your images. It's as easy as that. Turn off the stupid filters. Ulead DVD Workshop, for example, has these turned on, and it totally blurs the image. One of the first things a person should do after installing DVDWS2 is go to preferences and uncheck the "use anti-alias filter" option. You could supply 7200x5400 images (what is that? 20MP? -- as shot by a $35,000 MF DSLR) and it would still be blurred by this filter.

If you need a new author, depending in the project, I might be available. 8)

[steviespin]

thanks for the feedback everyone.

I was prepping in 720x540 in photoshop - they requested tiffs and would squish the images to 720x480 themselves.

I am web designer and don't have much experience in prepping gfx for a dvd menu, though asking for high res files (300 PPI) raised some obvious red flags.

I'll take your feedback into my next call with them. so it's sure that the high res files are not a solution (and a waste of my time to produce during my busy period

thanks
Steve

[steviespin]

lordsmurf - where are you located?
S

[steviespin]

I just had a meeting with the company - they said because of the compression process, I should give them high-res source files for the dvd menus.

does this make sense?

thx

[dun4cheap]

I agree with the hi resolution images, and depending on the aspect reolution you are working with you would want to make sure you keep correct aspect ratio.

Lordsmurf is right on with the filter issue as well. Pinnacle Studio 9 had a similiar issue where users would click the filter on in the render settings and then wonder why there final project did not look as sharp as the original source. Well these filters cause this problem. Now if you have a lot of bad footage and some good, using the filter would make all your footage look bad not just some.

Myself anymore, all my footage including for my DVD menus etc, usually come from HD sources. My still images have always come from a nice digital SLR 6-10 megapixel worthe.

example

16:9 something like 960x540 should fill the wide screen aspect but my source clips are usually 2-3 times that size. But in the end it also depends on the scaling process and mpeg encoder.

[lordsmurf]

lordsmurf - where are you located?S

I sent you a PM (private message). Check your PMs (top of page).

[lordsmurf]

. My still images have always come from a nice digital SLR 6-10 megapixel worthe. example
16:9 something like 960x540 should fill the wide screen aspect but my source clips are usually 2-3 times that size. But in the end it also depends on the scaling process and mpeg encoder.

Most of my menu images also come from a professional DSLR (currently a D200 and a D3 using good glass), or are custom drawn in Illustrator or Photoshop ... but they still have to be downconverted to 720x540 for the authoring application to accept them. The image processing in Photoshop (especially 3rd-party plug-ins like Fred Miranda's) far exceed anything an MPEG encoder would do. I wouldn't trust an MPEG encoder to down-convert one of my 10MP images and maintain any degree of quality.

Note that I rarely author 16:9. About 99% of my "authored with a menu" work is still 4:3. The 16:9 stuff tends to be menu-free. For 16:9, I'd still have an at-resolution image, I would not use a high-MP image. It just doesn't make any sense.

[lordsmurf]

does this make sense? thx

No. Not one bit.
The "compression process"? I don't recall seeing that in the video glossary.

Seriously, run away. Find somebody else.
I don't care who, but this is like the 4th red flag for me, from this conversation.

[dun4cheap]

Lordsmurf,

I prefer working in hi-resolution. All of my work now is in widescreen. All of my video I shoot now is HD. I use a Canon XTI with a 28-200USM lens normally and 2 Canon HV20's right now.

I even edit in HD from Liquid. What is nice about this is I can export to HD from the timeline or DVD from the same HD timeline. Menus and all.

[SCDVD]

Regardless of the video resolution that you use, the authoring program has to downsize an image to the resolution of the video if it is too big. You will get a better quality downsize if you do it in a good graphics program like PhotoShop. It has to be downsized somewhere. Why not do it in a program that will produce the best results?

[dun4cheap]

That is not all together true. First off, most of my menus are animated. So if I were looking to say do some pan and sooms on the background then this would absolutely not be the case. Further more, not all mpeg encoders are created equal, so you may want to run tests on the downsizing and quality before you make a final decision.

[lordsmurf]

I've run tests on pretty much every engine but the Scenarist hardware encoder (because I don't have access to one). MPEG encoders are very craptastic at downsize, as compared to Photoshop. If your menus are animated, then you're not creating a still menu, which is what we're discussing. But your animations should still be to-size for DVD as exported by After Effects, Premiere or whatever NLE / graphics solution you're using.

In your case, it appears that Avid Liquid is doing the downsize for you, prior to the encoding. Even then, you would do best to give Avid (at minimum) an image that is pre-sized to HD in Photoshop. The HD to DVD downsize may be acceptable in Liquid, but I'd still bet good money Photoshop (or a good PS sizing plug-in) would look far cleaner.

The person who created this thread does not appear to be doing an animation or submitting images for NLE work, but images for use in authoring. You're talking about something entirely different (and I would agree with the need for higher res, in that situation -- such as pan/zoom of a background in a motion menu).

Most MPEG encoders alias and add other distortions in images on downsize or upsize, with the single exception of 720x540 to 720x480 aspect compression (as the disc is assembled in 4:3 view, but must be encoded to the non-4:3 720x480 pixel ratio for storage).

[2Bdecided]

I don't have the numbers for NTSC land (I assume they're exactly the ones you're quoting!) but for PAL:

4x3: create at 788x576 square pixel, resize to 720x576
16x9: create at 1050x576 square pixel, resize to 720x576

These numbers are from the BBC, who also provide photoshop templates with safe areas etc included (16x9 and 14x9 only - no one makes programmes in 4x3 any more )...

http://www.bbc.co.uk/commissioning/tvbranding/picturesize.shtml

One thing to note is that I think it makes sense to resize to 720x576 (or 480) in your paint application - I don't understand the preference for giving the square pixels to the authoring app and letting it resize (unless it can't support 720x480 1:1 input, which a decent app should).

Cheers,
David.

[dun4cheap]

Even if your using a still image with an alpha channel with transparent masks I would recommend a high quality image. The other reason for the high resolution image, is for preparation of exporting to HD_DVD or Blue Ray or for any other HD export. Not many people would be able to tell any difference as to which program did the downsize from a Liquid timeline. However, I imagine one could from other programs depending on how the downsize was done.

Unfortunately as you have already identified, the mpeg encoders in most of these programs are not the greatest and only a few select have multi pass encoding.

Anyhow rule of thumb, the better the source the better the output. The real key though is to make sure the source aspect matches that of the outputed source or the round soccer ball becomes and egg.

[Alex_ander]

4x3: create at 788x576 square pixel, resize to 720x576
16x9: create at 1050x576 square pixel, resize to 720x576
These numbers are from the BBC...
http://www.bbc.co.uk/commissioning/tvbranding/picturesize.shtml

Their discovery of extra 18 'television pixels' is a good illustration of how dangerous the idea of square/non-square pixels can be sometimes. They take PAL pixel AR number (12:11) actually coming from 704/768, apply it to the image corrected to 768 for getting 4:3 and wonder why they don't get back their 720, then begin distorting the image.

[Cornucopia]

If you yourself do all the work doing the composing AND resizing, and you get it exactly to spec, then the authoring app should use it without any conversion at all (other than MPEG encoding), which should leave the image as CLOSE AS POSSIBLE to what you intended. That's why I suggested going straight to 720/704 x 480. Yes, apps can do 540->480 resizing, but I wouldn't rely on that. It's a VERY BAD idea to do that for video (think about interlacing---I've seen weird banding happen that way when done by ignorant co-workers!!!). In terms of actual output, composing at 640x480 and expanding (to 720/704) is probably closer to how the image would look anyway.

Scott

[lordsmurf]

Menus are almost never interlaced. Even when it is, the software understands what to do with the 720x540 image.

Remember the software documentation itself has requested 720x540.

I've tested giving authorware 720x540 vs 720x480. Many of the WYSIWYG authoring packages want a 4:3. If you give it 720x480, it'll resize to 720x540 to be worked with, then resize again to 720x480. Stuff gets lost in translation.

Even Adobe Premiere requests 640x480 for slideshows. It'll resize to your 720x480 video.

Small resizes are not as big a deal as huge megapixel sized images. To request a huge resolution image for a still menu is just clueless. THe only time I can see the need is with a fancy motion menu along the lines of what somebody else mentioned. But that's not what the OP was talking about that I can see.