You should always ask permission to use image that are not yours if you want
to make them public, In the context of labs and assignment, specify the source
of the image, and you have done to it
Scan : Scanner (from 300 dpi to 72 dpi)
Snap
: Digital Camera (any digital camera is enough for the web : 72dpi target)
If you want to print your pictures, simple trick (
2000 x 3000 pixels ... 20 x 30 cm)
Snap
: Digital Camera (any digital camera is enough for the web : 72dpi target)