Choose File > Import Command+I to bring an image into the current document. You can also paste an image, or paste a file copied in the Finder.
The imported image arrives as a floating selection centred on the canvas, so you can position it before clicking elsewhere to set it down. Its colours are added to your palette. Dottie is a 256-colour editor, so an image with more than 256 colours is automatically reduced to a 256-colour palette on import. If the image is a different size from your canvas, Dottie offers to resize the canvas to match.
A successful import is a single undo step—selection or new layers, palette colours, canvas resize, and any aspect-ratio change from the filename reverse together with Command+Z. A failed import leaves the document unchanged.
Dottie imports the common image formats: PNG, GIF, JPEG, TIFF, BMP, PSD, WebP, HEIF, AVIF, PICT, MacPaint, TGA, ICO, CUR, ICNS, XPM, Piskel (.piskel), and PICO-8 cartridge (.p8) files. Photographic or full-colour images are welcome—Dottie reduces anything over 256 colours to a palette on the way in. Piskel layers and frames become Dottie layers. A PICO-8 .p8 file imports the sprite sheet from its __gfx__ section using the PICO-8 16-colour palette. A MacPaint file brings in its picture and its 38 brush patterns together—see Use dither patterns in Dottie on Mac.
Dottie’s own .dottie files open directly with File > Open.
A PNG whose filename ends in -table-<width>-<height>—for example walk-table-16-16.png—is recognised as a sprite sheet. Dottie slices it on that grid and imports each cell as its own layer, ready for animation or tileset editing.
Sheets exported from Dottie use the same naming, so they round-trip back into layers automatically.
Tip A filename ending in -aspect-<x>-<y> sets the pixel aspect ratio on import, for artwork drawn for non-square-pixel displays.