File output size incorrect

[rontop]

I ran ad-detect to select the ads from a program, then did little adjustments to the selections. Then I selected "Invert selections" to select the program material I wanted to save. When I looked to see how much disk space I would need, this is what I saw.

ftp://upload:upload@videoredo.net/rontop/untitled.jpg

When I invert again:

ftp://upload:upload@videoredo.net/rontop/untitled2.jpg