 The Actual Canvas 
Given MIMEType: image/png
Used MIMEType: image/png
MIME types are the SAME.

Given MIMEType: image/jpeg
Used MIMEType: image/jpeg
MIME types are the SAME.

Given MIMEType: image/gif
Used MIMEType: image/gif
MIME types are the SAME.

Given MIMEType: 
Used MIMEType: image/png
MIME types DIFFER.

Given MIMEType: null
Used MIMEType: image/png
MIME types DIFFER.

Given MIMEType: undefined
Used MIMEType: image/png
MIME types DIFFER.

Given MIMEType: image/x-webkitbitmap
Used MIMEType: image/png
MIME types DIFFER.