DSWiki: DPI FAQ

DPI FAQ

(TJ_5.23.07)

Q. How many DPI should my supplied graphics be for use in my DS?

A. DPI is irrelevant in the video industry. The only thing you're interested in is the image SIZE, or the number of pixels making up the width and height.

In print, the closer together the points are, the higher the resolution. But in the world of video you have a fixed screen size (such as 720 pixels wide for SD, 1920 pixels wide in 1080 and so on).

So, the ONLY thing you need consider is the size of your TV format and whether or not you want to zoom into that image.
Let's take some examples:
1. You want to Capture an image into a 1080 project.
You need an image that's 1920 pixels wide by 1080 pixels high. (HD has square pixels, just like print graphics)

2. You want to LINK to an image in an SD NTSC sequence, and you want to zoom in 300%.
NTSC has a raster size of 720x480 pixels, but the pixels aren't square; they have a pixel aspect ratio of 0.9 (it's actually 0.904, but who's counting that close), so that makes the image size at 1:1 to be 720x531 pixels. You want to zoom in 300%, so your source image needs to be at least (3 x 720x531) = 2160 pixels wide x 1593 pixels high.

3. You want to Capture an image to a 16:9 anamorphic PAL sequence
SD Anamorphic PAL has a raster size of 720x576, with a pixel aspect ratio of 1.42 (or 1.422 for the pedants), making the square pixel equivalent of 1024 pixels wide, by 576 pixels high.

Note that for all of the above to work, you MUST have Capture Settings for "Computer Graphics - Square"
By now you should understand that as long as you know how big your image needs to be, whatever the dpi might be the image SIZE (in pixels) is the only thing you care about.



































Revised: Nov 28, 2007 4:04 pm