Warped Photos - Scanning Resolution for Stills - Etc.

[bpll]

Hello Everyone,

Your help would be very much appreciated. I know I will receive posts from many a kind person here – thank you in advance – really.

This will probably be so basic it will bore you, however I have the following problems/questions all pertaining to eventual use in a video slideshow (in which I will be using effects, including zoom effects ala Ken Burns) to be shown on a television:

* Note: I have the following software:
1. Puremotion’s Edit Studio 5
2. DVD Lab 2,
3. Adobe Encore 1.2
5. Windows Movie Maker

Questions:

1. What resolution should I scan my photos if displaying on 4:3 TV?
2. What resolution should I scan my photos if I want to display on 16:9 TV?
3. If I want to display 16:9 “look” on a 4:3 television can this be done? If so, how?
4. What resolution should I scan my photos if I want to project them on to a screen with a projector (home size – 8 ft. high, maximum)?
5. In putting together a video slideshow sample – should I simply do one for projector and one for television?
6. How do I correct the "warping problem" as listed below under Problems 1 and 2?

Problems:

1. Photos warp with “ease in” (Ken Burns) effect along right vertical margin when using Movie Maker. They warp as the picture is zoomed in upon.

2. Photos display warped within menu (along the margins only, not within the photo, i.e. the right vertical margin will be wavy, not a straight line, as if the photo is trying to be packed in to a space too small for it) Perhaps the pictures within the body of the video would appear warped as well if their margins could be seen – but I don’t know. As of now the menu photos are the only photos centred within the TV guide lines so as to ensure the full image is seen.

Troubleshooting Attempted (to no avail):

1. Resized the photo to be used as the menu picture to 720 x 480
2. Rendered DVDs using multiple programs - DVD Lab Pro2.0, Adobe Premiere, and Adobe Encore
3. Viewed on 4 different TVs and DVD players
4. Searched this forum, and others, for these answers

Observations:
1. Appears fine on computer monitors. This leads me to believe it’s an aspect ratio problem brought about in the process of rendering the project to DVD - but I really don't know.


Alright, I'm done. Any words of advice would be greatly appreciated.
Brad

[Capmaster]

1. What resolution should I scan my photos if displaying on 4:3 TV?
200 dpi

2. What resolution should I scan my photos if I want to display on 16:9 TV?
200 dpi

3. If I want to display 16:9 “look” on a 4:3 television can this be done? If so, how?
Change your scanning area so it's less square and more oblong. Scan at 200 dpi

4. What resolution should I scan my photos if I want to project them on to a screen with a projector (home size – 8 ft. high, maximum)?
200 dpi

5. In putting together a video slideshow sample – should I simply do one for projector and one for television?
No. Use the same one.

Your selected scan area will determine the shape of the projected or displayed image. If you maintain a 4:3 ratio of width pixels to height pixels, it should fit nicely on a 4:3 screen. The same logic applies for a 16:9.

And, as my answers indicate, anything higher than 200 dpi on a television is vast overkill

[gadgetguy]

I have to respectfully disagree with Capmaster. 200dpi is fine for slideshows that are showing the full picture at all times, but if you intend to zoom in and do pan and scan effects a higher resolution will produce better results. How much higher will depend on the effect so you'll probably need to experiment.
Also the pictures are usually scanned with square pixels. If you maintain the 4:3 ratio with square pixels, the resulting video will be distorted unless your editing software compensates for you. In general, a 640x480 photo resized to 720x480 will produce the correct appearance when viewed on a 4:3 TV. Can't help with 16:9. I've not worked with that yet.

[Cornucopia]

I'm in agreement with gadgetguy on this...

(Said this before, but here goes again)
Basically, you want to keep in mind the tenets of the Nyquist theorem. IOW, for real good quality looks, SCAN with at least DOUBLE the resolution (hopefully higher color bit depth, too!) and do your processing and then resize down to your final required resolution.
You got to remember that, for all your purposes, electronic media don't have "dpi" like print media do. It's all about the actual pixels.
SD video in NTSC-land is 720x480(non-square) and that's it, whether it's with a pixel size of 1/200th" or 1/4". (BTW, depending upon how far away you are from those 2 screens will determine which one looks to be better resolution).
But, for example, if you can't get over the DPI mindset yet, use 72dpi as a temporary rule of thumb.
So, at the very LEAST, you should always scan at 150dpi (But--WATCH YOUR ACTUAL PIXEL VALUES!). But that's with NO cropping, editing, processing, anything.
If you scan a postage stamp (~3/4" x ~3/4") at 150dpi, you've just saved a file that has ~112x112 pixels. Even with no processing, you'll end up with CRAP if you try to size it up to full screen (480x480, with pillarboxed sides). In this example, you ought to scan it at :

480 x 2(nyquist) = 960 pixels
960 / 3/4" = 1280dpi

So, you scan at ~1200dpi, do you cropping and processing, resize down to 480x480 and VOILA! you've got a beautiful fullscreen stamp.

*Note: since SD video is non-square, your last resize should take that into account (but all other previous resizes/processing SHOULDN'T).
Act like you're going to resize down to 720x540 or 640x480, but change it at the last minute to 720x480.
If you want to be real anal about it, you would resize to 704x480 (=(640 / .909090909) x 480)+ 8 black pixels padded on each side.
This all assumes 4:3 aspect ratio. If you want 16:9 AR, use 853x480 as your SQUAREPIXEL target size (same non-square as before though).

Clear as mud, huh?!!

HTH,
Scott

(for the technically-minded, this process is analogous to Oversampling in audio A-to-D converters, with similar benefits)

[Cornucopia]

Hint: notice I worked my way backwards to dpi from my final required size in the calculation.

Scott