Simple Sprite Maker

Simple Sprite Maker Help › Reference Images

Reference Images

A reference image sits behind your canvas so you can trace from a photo, concept sketch, or another sprite.

Loading a reference

  • From a file — open the reference panel and choose Load Image….
  • From the clipboard — copy any image, then choose Edit > Paste as Reference Image (⇧⌘V).

The reference image is saved inside the .ssm file, along with its opacity, scale, offset, rotation, and visibility. It travels with the project.

Adjusting the reference

The reference panel (the strip that appears above the canvas when a reference is loaded) groups these into six icon buttons. The three middle buttons — opacity, scale, and rotation — each open a small popover with a slider.

  • Show/hide — toggle visibility with ⌘T or from View > Reference Image.
  • Opacity — click the half-circle icon to set how transparent the reference is.
  • Scale — click the resize icon, or hold ⌥⌘ and drag up/down on the canvas.
  • Rotate (granular) — click the rotate icon to set an angle between -180° and 180°. This is a display-only transform; the underlying image isn't modified.
  • Reposition (drag) — hold ⌘ and drag anywhere on the canvas to move the reference image.
  • Rotate 90° — ⇧⌘R rotates the underlying bitmap clockwise (undoable, modifies the saved image data).
  • Flip — hold ⌥⇧⌘ and drag horizontally or vertically anywhere on the canvas to flip the reference. Works regardless of the active tool. Undoable.
  • Reset — the counter-arrow button resets scale, position, and granular rotation back to defaults.
  • Remove — the trash button clears the reference entirely.

Sampling colors from the reference

Hold ⇧ while clicking with the Eyedropper (⌘I) to sample the color of the underlying reference pixel rather than the canvas pixel. A small dot indicator shows the exact sampled position. A normal click (without ⇧) samples the canvas pixel as usual.

You can also reach the reference Eyedropper without switching tools: while Pencil or Bucket is active, hold ⌥⇧ and click — that's a one-shot reference pick that returns you to your drawing tool.

Stamping the reference into pixels

The Stamp Reference to Pixels… command turns the visible portion of the reference into a starting set of pixels on the canvas. Open it from the stamp button in the reference panel, the Reference Image submenu, or ⇧⌘T. Whatever portion of the reference currently overlaps the canvas, at its current scale and position, is what gets sampled. The granular rotation slider is currently not respected by the stamp — use the 90° rotate (⇧⌘R) for orthogonal stamps.

Results look best on art with clean silhouettes (game sprites, icons, logos) and rougher on photos or smooth gradients. Treat the stamp as a starting point you'll touch up — it's not a one-click converter.

Settings inside the sheet:

  • Palette source — Current palette snaps every output cell to the nearest color in your active palette. Unconstrained writes the sampled RGB directly.
  • Alpha threshold — reference pixels below this opacity are treated as transparent in the output.
  • Color matching — Perceptual (Lab) uses CIE Lab distance and typically picks more natural-looking palette matches than RGB nearest. Only meaningful when constrained to a palette.
  • Dithering — Floyd–Steinberg diffuses quantization error across neighbors, producing smoother gradients at the cost of grain. Ordered (Bayer 4×4) applies a stable pattern that's frame-coherent across animations.
  • Apply to — overlay onto the current frame, replace it wholesale, or insert a new frame after the current one.
  • Preserve existing pixels under transparent areas — when overlaying, keep whatever was already on the frame where the reference is transparent. Turn off to clear those cells instead.

The live preview on the left updates as you change settings. The whole stamp lands as a single undo step.