Build a colour-tile mosaic

The raster is partitioned from the top-left into square cells. Every source pixel in a cell contributes to one mean RGBA colour. That colour fills the cell except for the chosen top and left grout strips, producing a repeatable grid whose geometry scales with export resolution.

Tile size

The side of each square cell in pixels.

Grout width

The separator reserved inside each cell.

Grout colour

The literal output colour written into those separators.

The origin is fixed at the top-left, so an important eye or edge can land under grout. Change tile size to move the grid relationship. A grout width near one third of the tile leaves too little colour area and makes the picture read as a lattice rather than a mosaic.

The preview, draft and export all run the same kernel. Parameters measured in pixels are scaled with the source, so a chosen tile, band or radius does not become unexpectedly finer in the downloaded file.

How is this different from pixelation?

Pixelation fills adjacent blocks with means but no separator. Mosaic reserves a visible grout strip inside every tile, making the grid part of the result.

Are the tiles sampled or guessed?

Each tile colour is the arithmetic mean of the source pixels under that tile. No palette or model is involved.

Can grout be removed?

Yes. Set its width to zero and the result becomes a regular square-block mosaic without separators.

• PixelateSquare or hexagonal blocks, each one flat, with optional palette quantisation.
• PaintingSmoothed regions, reduced colour steps and measured contour weight.
• PosteriseContinuous tone reduced to measured channel levels, with optional pre-dither.
• The effects labAll six effects, chosen from your own photograph rather than from a list of names.

Rendered on your computer, not on a server.