Post #161741

Author: Moth3r
Parent topic: Citizen's Aspect Ratio Calculator Tool for your browser
Link to post in topic: https://originaltrilogy.com/post/id/161741/action/topic#161741
Date created: 8-Dec-2005, 3:17 AM

I see what you've done now, you've calculated how to turn a 16:9 anamorpic image into a 4:3 letterboxed image - compress 576 lines down to 432 and add 72-line thick bars top and bottom.

That's not what we're doing here. The image starts off in 4:3 and we want to make it 16:9. To do that it must be stretched vertically by (16/9)/(4/3)=1.333.

After cropping out the black bars with crop(0, 126, 720, 324) we have 324 lines left.

324 * 1.333 = 432.