Using Other Webcam Image and Image Size?

I’ve got WD setup to use an image from a third-party webcam software. This is working fine now. I recently decided I wanted to change the image size and ran into this question again.

What do the “Image Width / Height Adjust” and “File Image Width / Height Adjust” actually do? I seem to have to pick a strange combination of these values to get the image to look right. I currently have the “Image” controls set to 320x240 and the “File Image” set to 328x268. This produces an image with the demensions of 320x241. The original image is 640x480. I got to this set of numbers by trial and error, but I don’t think it should as dificult as I made it.

How do these three dimensions (original image, image, file image) work together? If my original is 640x480 and I want the final image to be 400x300, is there a way to calculate what numbers need to be in these fields?

Thanks

I guess somebody decided to cleanup the spam replys. Thanks.