Aspect ratio of a pictures in the Slide Show ?

[mnegahban]

I am trying to crop my pictures to correct aspect ratio for NTSC format TV using DVD.

I have orignially scanned several thousand negatives at 2900 dpi, and saved them in TIFF format. I would like to make an slide show using MYDVD (or other software if someone suggest) and burn it into DVD-R media. I am trying to fill the whole TV screen without making the contant to look fat or thin. I also want to avoid the black bars. After reading so many post, I narrow down the ratio to the following

4 x 3 (TV)
720 x 480 (DVD)
704 x 480 (DVD or SVCD)

I am confused about buring pictures in DVD and displaying in a TV (with SVHS) input.
Should the pictures' aspect ratio follow the TV or DVD

Thanks,
Mohammad

[Vejita-sama]

You are confuding display aspect ratio (DAR) with resolution. You have have a given DAR at any resolution. There are three DARs you're likely to deal with:

1:1 PC
4:3 TV
16:9 film and widescreen TV

ALL PC video has a DAR of 1:1. You're TV can ONLY display 4:3 video. So you need to convert your 1:1 progressive video into 4:3 when your encode/author.

DVD has three supported resolutions: 720x480, 352x480 and 352x240. All of these resolutions have DAR of 4:3. Again don't confuse DAR with resolution (aside DVDs can also be flagged with a DAR of 16:9 but that's not really important for this topic )

You say you want to aviod 'the black bars' well those bars (like letter boxing) are necessary to maintain the source aspect ratio. You have two choices letterbox your pictures, or crop them to fit full screen.

I personally recommend letterboxing (as you can see the entire source picture).

[mnegahban]

Thanks for making me clear about the "Display Aspect Ratio" vs the "Resolution".

So If I decided to crop, the ratio of "720 x 480" would prefectly fit into DVD and TV.

Since my pictures have much more pixles, I am planing to crop this ratio (but leave it at High resolution). Then save these files in TIFF or PNG. and then let the MYDVD software to down size these files to actual (720 x 480) pixles in JPEG format for DVD burning.

Does the precedure make sense
How many pictures can I fit in DVD-R without any transition effect or sound

[MachineMan]

You should do a quick test with a few pictures useing your slideshow software before you spend all that time individually cropping each jpeg. I think that the software will automatically dislplay all the pictures with out distortion if they are already at aspect ratio 4:3. What is the resolution of your stills?

[mnegahban]

My original pictures were scanned from the negatives at 2900 dpi. The picture is about 4100 x 2700, which they are saved in TIFF with LZW compression (about 26MB file).

[MachineMan]

Those are huge! Im not sure what the authoring software would do to them but if it preserved that size you probably would get many pictures in your slideshow. Anyway that resolution would be way over kill for a typical TV. It might convert them down to a DVD resolution??

Also some photo software packages have a batch process feature where you could specify an output format and it will convert all the pictures automatically rather then you doing it manually for each one.

Try loading a few into your MyDVD and see what happens.

[mnegahban]

I just tested different aspect ratio, and here is the result. I am going to explain the process for ONE picture in 3 different aspect ratio.

Picture 1. Original Picture...................................(4112 x 2684) pixles
Picture 2. Cropped to "4x3" aspect ratio...........(3545 x 2659) pixles
Picture 3. Cropped to "720x480" aspect ratio...(4009 x 2673) pixles

the above picture were imported (PNG format) into MYDVD software. The software did all the convertion to create a slide show. Then the Slide show was burned into DVD-R media.

The Slide show was viewed both in TV (using set top DVD), and in PC ( using the PowerDVD).

Picture 1 has a thick horizontal black bars on top and bottom.
Picture 2 has NO black bars at all
Picture 3 has a thin horizontal black bars on top and bottom.

First interesting observation was that picture 1 and 3 had a black bar, which a jitter could be observed at the edge of the video where it met the horizontal black line. It might be that the black line intensify the effect of the jitter.

Second interesting observation was that the picture 2 was chopped off at all four edges in TV only However that same picture 2 was displayed in PC without any cutoff For example the very top of a person's head was NOT visible in TV, but it was without any problem in PC
The pictures 1 and 3 did not have any problem because they had the whole picture PLUS the black bar. I don't know how to calculate the "TV Safe Zone" (like 97% of a frame or ...)

In one hand a thin black line helps to view a complete picture frame in TV, and on the other hand there is some jitter at the edge of the video with the black line.
It seems that there is no perfect world even in DIGITAL world

[themichael]

See the following posts about safe areas:

https://www.videohelp.com/forum/viewtopic.php?t=162703&highlight=safe+area

https://www.videohelp.com/forum/viewtopic.php?t=163766&highlight=safe+area

These should help, but you can also search for posts on MPEG stills, slideshows, and overscan.

Mike