The way to get the Gallery and the Music apps to ignore folders on your phone is to create an empty file in the folder called "
The easiest way to create that file is to plug your phone into a PC, explore the phone until you can find the folder that has your unwanted icons in it.
Then if you open Windows Notepad, click File -> Save As, navigate your way to the folder on the phone and then make sure that Notepad's Save As Type box says All Files (*.*) and does not say "Text Documents (*.txt)" you can now type
.nomedia (note the full stop/period at the start of the file name) and click Save.
If you've done it right the file should not have a Notepad icon in in Explorer, it should just have a default plain white, rectangular icon. Now safely remove the drive, unplug your phone and (after your phone's done a media scan) the icons should disappear from the gallery.