[srauly]

We all talk about how DVDs have 480 lines of resolution and all of the scaling that has to be done to view this on a 1024x768 projector, but what about vertical resolution? How many lines of vertical resolution does a DVD store? What about HDTV signals?


My thoughts behind asking this go back to another post I made questioning whether there might actually be any advantage to projecting a DVD with a lower resolution (e.g. - SVGA) projector vs an XGA projector.


Scott

 

[Wendell R. Breland]

Quote:

Originally posted by srauly: How many lines of vertical resolution does a DVD store? What about HDTV signals?

Scott, In the simple form the max V resolution: DVD=480, HDTV 1080 or 720 lines.


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Wendell

Technical Services Supervisor

MAETV

 

[srauly]

I believe that's horizontal resolution. I'm looking to find out more about the vertical resolution.


Scott

 

[JeffY]

NTSC DVDs are 720x480.


Jeff

 

[Morbius]

Scott,


The "480" lines IS the vertical resolution.


The lines are stacked one above the other. The more

lines you have - the greater the resolution in the

vertical direction.


Now if you want to know how many pixels in a line - that's

horizontal resolution.


Jeff gave you the answer for DVDs which are 720 pixels

horizontal resolution by 480 lines vertical resolution.


Greg

 

[srauly]

 http://www.avsforum.com/ubb/redface.gif Doh! I had a feeling I was going to mix them up. As a programmer and graphic artist, I should know better.


Thanks for the info, and sorry Wendell.


OK, how about HDTV's horizontal http://www.avsforum.com/ubb/wink.gif resolution?


Scott


[This message has been edited by srauly (edited 10-05-2001).]


[This message has been edited by srauly (edited 10-05-2001).]

 

[Tryg]

this post may help
http://www.avsforum.com/ubb/Forum31/HTML/000163.html

 

[dreamer]

HDTV is either 1920h X 1080v or 1280h X 720v.


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*********************

Kirk Ellis

G1000 D-ILA, HTPC, Panamorph, Vutec 107x60 (16:9),

Dish 6000 (HBOHD,SHOHD,CBS,NBC,ABC,WB,FOX,UPN, KCET -- does it get any better ?)

 

[Jonmx]

XGA is sufficient to display the total resolution of DVD material. In theory a 16:9 panel or a panamorph adds nothing but maybe some additional light output.

 

[srauly]

Are there actually devices out there that can handle a horizontal resolution of 1920?


Scott

 

[Frode]

Srauly - yes, they're called CRTs http://www.avsforum.com/ubb/tongue.gif


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/frode

 

[Don O’Brien]

It should be pointed out that the big difference among the 4:3 NTSC sources/technologies is the horizontal resolution, not the vertical resolution. The only reasonable way to compare horizontal resolution is to quote TVL, which is the number horizontal lines per picture height. For DVD the horizontal resolution on a 4:3 screen would be 540 lines (720/1.33), 16:9 screen 405 lines (720/1.77778).


All NTSC sources contain approximately 480 interlaced horizontal lines that make up our appreciation of the vertical resolution. The number of vertical lines (analog) or pixels per horizontal line (DVD, computers), varies the horizontal resolution.


Lastly, when comparing the two competing HDTV standards it is important to consider the issue of temporal resolution. If you apply the Kell factor to the 1080i signal it results in simliar vertical resolution for 720p and 1080i HDTV.


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Don O


[This message has been edited by Don O'Brien (edited 10-05-2001).]

 

[John Mason]

Quote:

Originally posted by Don O'Brien: Lastly, when comparing the two competing HDTV standards it is important to consider the issue of temporal resolution. If you apply the Kell factor to the 1080i signal it results in simliar vertical resolution for 720p and 1080i HDTV.

Excellent point, Don. For folks that aren't that aware of the differences, perhaps laying out the numbers would be useful. The temporal or time difference isn't that apparent when you simply say 720pX1280 versus 1080iX1920.


So I'll use the resolution data for both scan formats found by the FCC's experts committee . Keep in mind the resolution numbers below are for stationary black-and-white test patterns, the data usually specified for resolution. The resolution decreases for moving test patterns. Also, color signals add additional pixels, as the modified FCC chart data at the hyperlink above shows.


TOTAL PIXELS/SEC. FOR 720P HDTV

550 Vert. Res. X 1139 Hor. Res. X 60 frames/sec =

3.76 million pixels/sec.


TOTAL PIXELS/SEC FOR 1080I HDTV

800 Vert. Res. X 1638 Hor. Res. X 30 frames/sec =

3.93 million pixels/sec.


Recall a recent fairly lengthy thread that debated this. Believe some pointed out that 1080i is actually delivering 60 fields/sec (2 1/60-sec fields = one 1/30-sec frame). -- John