
Melkiador |

A spell in a scroll is a different form than a spell in a spellbook, so a non-wizard definitely cant copy from scroll to book and have any meaning. One is a spell that is waiting to be finished and the other is instructions for casting a spell. Copying from scroll to scroll won’t do much because you have to put the magic of the spell into the scroll for it to have any meaning.
Copying from spellbook to spellbook is the only thing that could maybe be possible, but even that doesn’t seem to be supported by the rules. While the writing in a spellbook isn’t magical, it does require a certain amount of expertise and even special inks.

OmniMage |
Wizards (and other spell book users) can copy a spell from a scroll into a spell book. Anyone else trying to do the same won't work. They don't have the class ability needed to bind the spells into the special inks as they copy spells. Other casters don't need spell books so why would they have the ability to copy spells into spell books?
Copying a spell from a scroll to a spell book will destroy the scroll. Its one of the more expensive ways to acquire spells for your spell book. More so if the scroll includes expensive material components. On top of that, you still have to buy the inks to scribe the spell into the spell book.
I suggest you instead try to find a wizard and ask if you can copy their spells. The copy fee is normally 1/2 the price to write the spell into your spell book.

avr |

There are class features which reference which class created the spellbook, e.g. alchemists can copy from a wizard's spellbook but wizards can't copy from an alchemist's formula book; but magus and wizard spellbooks can be used interchangeably. This means that which class you are matters for copying spells, which implies that without a spellbook class feature you can't usefully copy spells.

Chell Raighn |

There are class features which reference which class created the spellbook, e.g. alchemists can copy from a wizard's spellbook but wizards can't copy from an alchemist's formula book; but magus and wizard spellbooks can be used interchangeably. This means that which class you are matters for copying spells, which implies that without a spellbook class feature you can't usefully copy spells.
The alchemist rules for coping from a wizard spellbook is a special case scenario... it’s not a hard fast rule for all spellbook users. An alchemist formula book is read more like a chemistry than a spellbook, they are able to decipher a spell and break it down to mundane alchemical components to distill a simimagical extract that they need only infuse a tiny bit of magical power into to make functional. It is far easier to break the instructions down one direction than the other. Think of it like a baker and a chemist making the same cake but while the baker has a simple recipe out of a cookbook the chemist has a recipe of the exact chemical composition... the chemist can take that cookbook recipe and break it down to chemical components but unless the baker is knowledgeable enough in chemistry the recipe won’t make any sense to them any more.

Mysterious Stranger |

Considering that spell books are specific to the character even another character of the same class cannot copy directly to another characters spell book. The section on Wizards spells and borrowed spell books is pretty specific that using a spell book that is not your own does not guarantee you can prepare the spell. A spell copied by someone else would fall into this category.
Also the rules state a wizard can add spell to his book and give specific methods to do so. They don’t mention anyone else being able to add spells to your book.

Mudfoot |

RAW, no, as above posters say. I'd allow it for a feat and a Spellcraft, Knowledge-Arcana or Linguistics-Forgery roll (after all, the ability comes for free with 1 level of wizard and isn't exactly awesome). You might do away with the feat if you can make more than one of the above rolls at a substantial DC. YMMV.