I am brazilian, living in the U.S. with a F1 Visa, and If I decide to visit Canada, do I need a Visa? Since I am not american, and if I was in Brazil, I know they require Visa to go to Canada, if you depart from Brazil... Do I need Visa departing from the U.S. Thank you

No, you can not come to Canada without a Visa.

Only US citizens may enter Canada without a Visa, and since you are not a US citizen, but rather a citizen of Brazil, you will need a Visa.

Since, citizens of Brazil require Visas.

Source: http://www.trailcanada.com/travel/planning-visas.asp