Ok, I used scale_x/y and FILTER flag like Kartoffel said and it worked ,but there is some line on the right side/bottom of the screen that the panel doesn't cover, is this normal? I have to decrease one or two pixels from the size of the panel when I use the 2 instructions for resizing (f.i. if the size of the image file is 1000x500 ,I have to change it in the script to be 998x498) and it works ,but should I do this every time or there is a permanent solution?