exporting still image in 16:9 from a video 16:9

Hello,

I have some problems for exporting some images from a video file.
I try FILE- EXPORT-VIA QUICKTIME CONVERSION-STILL IMAGE
until here is ok, but how can I modify formats parameters? video file is in 16:9 but when I export the image is in 4:3 (par default), I didn't find where i can change this.
if someone could help me...I spent a lot of time with this (little) thing. Thanks

What the format here? DV? NTSC? All DV NTSC is 720x480. You need to resize in a graphic application to 853x480.

DV PAL

resize, here is the problem

What's the problem? You resize to 1024x576 for PAL.