I'm sorry I didn't explain myselft clearly, I don't mean Flash Fullscreen mode, I just want a gallery where you don't see any bit of background, no gray area anywhere, so that photos do resize to browser height proportionally but they would just crop if browser is resized horizontally.

Thanks for your time Felix.

Yes I have both of them set to 0, the problem is not with the space between images (there is none), but with the space above and below horizontal images when there is a horizontal image next to a vertical one on the left and you resize the browser horizontally. It's easy to understand with a screen capture.

arnauanglada dot com slashdot problem dot jpg

They are the same height in pixels, they look equal when the browser is fullscreen or similar proportions, but they lose this proportions when the browser is resized horizontal like in the screen capture, then the horizontal picture gets smaller (so leaving the spaces above and below) but the vertical ones keeps to the full browser height.

I need to set it so the photos only resize down when the browser is resized vertically, and that they crop when it is resized horizontally.