Editing Planar (computer graphics) (section)

==Advantages and disadvantages==
Planar arrangements offer space and time efficiencies over packed arrangements at bit depths that are not powers of 2. As an example, consider 3 {{abbr|bpp|bits-per-pixel}}, allowing 8 colors. With planar arrangements, this simply requires 3 planes. With packed arrangements, supporting exactly 3 bpp would require either allowing pixels to cross byte boundaries (incurring time costs due to complications with addressing and unpacking pixels) or padding (incurring space costs, as each byte would store 2 pixels and have 2 unused bits); historically, this is one reason (though not necessarily the main one) packed pixels used bit depths that fit evenly into bytes.

Planar arrangements allow for faster bit depth switching: planes are added or discarded and (if colors are indexed) the palette is extended or truncated. Consequently, support for higher bit depths can be added with little to no impact on older software. Ease of bit depth switching also allow elements with different bit depths to be easily used together. 

A disadvantage of planar arrangements is that more RAM address cycles are needed for [[scrolling]] and [[animation]]s.