A screenshot map is a single image of a location within a video game compiled from various screenshots. The screenshots are usually taken using an emulator in order to achieve "pixel-perfect" quality. Adjacent screens are pasted together in an image editing program, and the onscreen sprites are usually removed. The maps allow large in-game areas (usually referred to as "levels", "stages" or "worlds") to be seen in their entirety. More accurately, these are maps as much as they are omniscient views of (fictional) locations.
Screenshot maps were a common feature of the tips, hints and walkthroughs sections of game magazines throughout the late 1980s and early 1990s, such as Nintendo Power. They are fairly rare in modern gaming due to the dwindling number of games rendered in only two dimensions, but are popular in retrogaming where the two required ingredients—2D and emulators—are both common. The current uncommonality of these maps and the reminiscence of older two-dimensional games leads to the creation of many screenshot maps for nostalgia rather than just for navigation. Web sites such as VGMaps, among others, are based around the collection and creation of screenshot maps for either reason.
As the name suggests, screenshot maps are maps constructed primarily from screenshots. In the most common creation process, the screenshots are taken during play (typically on an emulator) and are then spliced together in an image editing program. This can be a time-consuming process largely dependent on the size of the area mapped, as there could be hundreds of screenshots used, with each screenshot carefully hand-placed to ensure that pixels are aligned correctly.
The number of screenshots required is also dependent on the amount of redundancy involved; often it makes more sense to take the next screenshot even without scrolling over a full screen, as the "overlapping" area helps to ensure proper pixel alignment. Taking multiple screenshots of the same area allows for the synchronizing of dynamic elements or the removal of character sprites if desired.
Some games may use parallax scrolling, so the basic screenshot approach may not lead to an aesthetically pleasing map. The background layer(s) should be assembled separately from the foreground before being combined. This may require that the background be enlarged, extended or modified at the mapper's discretion so that it better "fits" with the foreground.
Dynamic elements (animated tiles, moving platforms, etc.) should also be harmonized. Sprites, especially the main character sprites, are usually edited out, as they don't need to be seen on every screen. Enemy sprites are usually excluded as well. This makes it more like a literal map that only shows a location and not its inhabitants, but also because they may be hard to consistently place, as it would look more tidy to not have any enemies at all than to have them appear while performing various actions. It would be assumed that a player using a map for gameplay would know how to deal with enemy characters and they would be more concerned about the terrain or the direction they should be going. (However, if enemy placement data can be extracted from the game's code, that might allow for consistent placement of them if the mapper so desires.) There are some common exceptions, such as bosses, or the mapper might choose to show the main character sprite just once to indicate a starting position.
While screenshots are usually taken while playing, for some games it may be simpler to rip images and/or layouts directly from the data in the game's code. Another advantage of this method is that information which would not be visible from screenshots during normal play (e.g. invisible objects, difficult-to-reach areas, etc.) may also be extracted. Dynamic elements will typically be harmonized by default when using this method.
The mapper may also choose to label points of interest, such as the locations of items or treasures, boss characters, the paths of doorways and warp points, etc. They may also add gameplay tips relating to the area that is mapped.
Some mappers prefer to leave the areas completely untouched, while others prefer to put accompanying strategies or other relevant information directly on the image. Mappers may choose to fill in areas the original game designers left blank with tiles copied from other sections to create a more continuous, picturesque image. When adding to or altering in-game elements, one addresses the question of whether priority is placed on accuracy or aesthetics, and the approach chosen depends on whether its purpose is navigational or nostalgic.
Due to the nature of pixel art it is preferred to use lossless image formats such as PNG.