Hi Andrea,
If I understand correctly, you are using "saveas" on a figure handle to save an image. When you do this, the image is translated. However, when you use the GUI interface (File > Save As...), the image is saved properly. Is this correct?
I am not able to reproduce this behavior. Could you please provide the code you are using to save the figure, and the steps you are taking in the GUI to save it?
Note that by default, "saveas" will save a figure handle as a FIG file. However, the GUI can save a figure as many different types, including JPEG and PNG.