Backgrounds are used to display visual novel backgrounds as well as CGs (computer graphics; a common term for full screen art in visual novels that isn't overlaid with sprites). They can be viewed and edited through the background editor.

Replacing

Backgrounds can easily be replaced in the background editor. Simply press the "Replace" button and select a new image file from disk. This will open the built-in crop & scale tool to let you size your image to fit the standard set of background sizes (see below).

Crop and Scale

Once an image file has been selected after choosing "Replace", a box overlay cut-out will be layered over the imported bitmap. Using the mouse, you can click and drag the image to adjust its crop; the portion that is uncovered in the box will be the final image. Additionally, you can use the mouse wheel to scale the image up and down. Additionally, you can use the arrow keys to move the image in any direction more precisely.

Finally, you can press the "Apply" button to scale the image to fit the crop, preserving its aspect ratio.

Background sizes

Background Type	Size (WxH in pixels)	Notes
KINETIC_SCREEN	256x192	16 color images, so make sure your image is exceedingly simple
TEX_BG	256x192
TEX_CG	256x192
TEX_CG_DUAL_SCREEN	256x512	Displayed on both screens, but each portion is taller than the full screen (scrolled with BG_SCROLL)
TEX_CG_WIDE	512x192	Displayed on bottom screen, but wider than the full screen (scrolled with BG_SCROLL)
TEX_CG_SINGLE	256x256	Displayed on bottom screen, but taller than bottom screen (scrolled with BG_SCROLL)

CG Titles

Many CGs have titles associated with them that are shown in the Extras CG viewer. Where this is the case, a text box will be shown letting you modify the title.