Epson 660 - Manual (Page 43)

C OMBO T AB
Each item in this tab:
Invert
If you click this button, the current frame will be converted into inverse color. This means the brightness
value of each pixel in the channels is converted to the inverse value on the 256-step color-values scale.
Horizontal mirror
This effect is not displayed in the preview area but be realized on the scanning result.
Rotate
You can type a rotating angle into the editing cell or drag the scroll bar.