If your flight to Korea is direct from Canada, you can enter Korea visa-free for up to 30 days during your transit.

Here's what TIMATIC, a database of visa requirements, has to say (follow the first "For details, click here" link on the linked page):

Korea (Rep.) (KR)

Visa Exemptions:

• Passengers with a visa issued by Australia, Canada, New Zealand or USA to nationals of any country except for China (People's Rep.), Cuba, Iran, Macedonia (FYROM), Sudan and Syria, only if in transit through Korea (Rep.):

-holding confirmed onward tickets on flights departing within 30 days; when

-arriving from a third country, departing to the country that issued the visa (e.g. DEL-ICN-YVR); or

-arriving on a direct flight from the country that issued the visa (a visa that expired on departure from that country is accepted), departing to a third country (e.g. YVR-ICN-DEL).

In order to be exempt from needing a Korean visa, you need to meet the first requirement listed above, the second requirement, and either the third or the fourth.

• You meet the first requirement because you're from the Philippines and hold a valid Canadian visa, or at least one valid at the time of your departure.
• You meet the second requirement because you have a confirmed onward ticket from Korean to the Philippines.
• You meet the fourth requirement if you will be arriving on a direct flight from Canada.

So, as long as you arrive on a direct flight from Canada (not, for example, Canada -> China -> Korea), you will not need a Korean visa.

You can enter Korea visa-free for up to 30 days during your transit.

Here's what TIMATIC, a database of visa requirements, has to say (follow the first "For details, click here" link on the linked page):

Korea (Rep.) (KR)

Visa Exemptions:

• Passengers with a visa issued by Australia, Canada, New Zealand or USA to nationals of any country except for China (People's Rep.), Cuba, Iran, Macedonia (FYROM), Sudan and Syria, only if in transit through Korea (Rep.):

-holding confirmed onward tickets on flights departing within 30 days; when

-arriving from a third country, departing to the country that issued the visa (e.g. DEL-ICN-YVR); or

-arriving on a direct flight from the country that issued the visa (a visa that expired on departure from that country is accepted), departing to a third country (e.g. YVR-ICN-DEL).

In order to be exempt from needing a Korean visa, you need to meet the first requirement listed above, the second requirement, and either the third or the fourth.

• You meet the first requirement because you're from the Philippines and hold a valid Canadian visa, or at least one valid at the time of your departure.
• You meet the second requirement because you have a confirmed onward ticket from Korea to the Philippines departing within 30 days of arrival in Korea.
• You meet the fourth requirement because, as you mentioned in a comment, you will be arriving on a direct flight from Canada.

So, you will not need a Korean visa to enter the country during your 16-hour layover.