Guides

How to make a brick mosaic from a photo

A brick mosaic is a grid of 1 × 1 parts, one on every stud, that reads as a picture from a few steps back. You can build one from a LEGO® Art set, have one made from a photo at a LEGO Store’s Mosaic Maker, or design your own from any photo and buy the parts. This guide covers the third way. Three choices decide whether it looks like your photo: its size, its colours and what it is built on.

Start with the size

Size matters more than any colour setting. We built four test pictures (a photo of a Labrador and three paintings: Hokusai’s Great Wave, Vermeer’s Girl with a Pearl Earring and Van Gogh’s Starry Night) at several sizes and compared them side by side. At 48 studs, the size of one LEGO® Art canvas, the photo was hard to recognise and even the paintings lost their faces. At 96 studs the pictures read clearly, and at 128 faces, stars and the crest of the wave became sharp.

Part counts depend on the picture’s shape; each stud is 8 mm. LEGO Art’s 48 × 48 works well for artwork drawn for that grid. For an ordinary photo, plan on 96 studs or more.

Choose a photo that survives the grid

A mosaic keeps shapes and contrast and loses texture. One subject, a plain background and a tight crop work best. Dark against dark disappears: in our Labrador photo the chocolate fur and the shaded grass merged into one black area at 48 studs, and the head and tongue only separated at 128. Very dark fur can also come out black and grey rather than brown, because the darkest pixels carry almost no colour to match.

Colours: real parts only, and fewer than you think

Every colour has to exist as a real part. The 1 × 1 round tile (part 98138) has been made in 47 opaque colours, and 38 of them appear in ten or more sets, which makes them easier to buy. Square tiles (3070b), round plates and square plates (3024) each have their own colour lists, so changing the surface part changes the palette.

Limiting the number of colours costs less than it sounds. Taking the Labrador from 26 colours down to 12 raised the average colour difference by about 0.3 (CIEDE2000), which you cannot see at viewing distance, and fewer colours means fewer orders and less sorting. Official sets go further: the photo-portrait Mosaic Maker set (40179) uses five colours on one 48 × 48 baseplate.

Dithering: for gradients, not photos

Dithering spreads each stud’s colour error onto its neighbours. On a grey ramp it helps: with three colours, Floyd–Steinberg cut the average brightness error of 8 × 8 patches from 9.2 to 6.4. On photos it scatters stray colours. Our Labrador’s fur picked up blue, pink and brown dots, and 22% of the studs became noticeably more saturated than the photo. Use it for skies, sunsets and other smooth gradients.

Pick the base

• LEGO® Art panels. LEGO Art sets use 16 × 16 panels (part 65803) joined through the holes in their sides with Technic pins (2780). Use three pins on each edge that two panels share: a 3 × 3 panel picture has 12 shared edges and needs 36 pins. The picture holds together as one piece and grows in steps of 16 studs. The panel has only been made in six colours.
• 48 × 48 or 32 × 32 baseplates (4186 and 3811). Easier to buy, but they only fit sizes that are whole multiples of their side, and they do not clip together, so mount them on a board or in a frame.

Buy the parts and build

A custom mosaic is mostly 1 × 1 parts in a handful of colours, so it suits ordering in bulk from Pick a Brick or BrickLink. Order a few percent extra of each colour; small tiles get lost. If you already own LEGO Art sets, a mosaic designed around their colours and counts needs few or no extra parts.

Build one panel at a time from a numbered chart, with each colour sorted into its own tray, and mark the top edge of every panel before you join them.

MOCsmith’s mosaic maker does the design steps above in your browser: crop, size, palette, surface part and base. It can fit the picture to sets you own, and it exports a PDF chart for each panel, an LDraw model and a CSV parts list.

Open the mosaic maker