Post cover image : W=695, H=254px
Channel image : W=695px, H=300 px
Course and library thumbnail image: W=345px, H=255 px
Course background cover image: W=1014 px, H=330 px
Event cover image: W=1010px, H=320 px
Invite page banner image: W=1040px, H=334px
Community image: W=970px, H=260px
Community logo: W= 90px, H =90px
Community favicon same as before W=32px, H=32px