Cross Stitch Pattern Maker from Photo

Turns a photo or drawing into a cross-stitch chart sized to your Aida count. Every cell gets the nearest floss colour and a symbol, and the page shows stitch counts and skeins per colour, the finished size and the fabric to cut. Use it to make a cross stitch pattern from a photo, or to limit a design to the floss you already own.

How to use

1. A chart made from the strawberry sample is shown first. For your own photo, click "Drop a photo or drawing here or click to choose" or paste it with Ctrl+V.
2. Choose the count (11, 14, 16, 18 or 22) under "Aida fabric", then set "Stitches across" or "Finished width, cm" under "Set the size by"; the height follows the picture.
3. Set the number of floss colours with "Use fewer colors (keep the common ones)" and "Most colors". If many single cells remain, raise "Tidy small specks". Turn on "Add backstitch (outline)" for outlines.
4. Under "Cells show", pick "Color", "Symbols (black and white)" or "Color and symbols". Tap a colour in the key to show only its cells while you stitch.
5. Use "Save as PDF", "Print" or "Save PNG". A large chart is split into sheets at the "Printed cell size", and joined sheets repeat 2 cells.

How it works

• The picture is divided into cells, each cell takes its average colour, and the nearest floss colour is chosen in the CIELAB colour space with the CIEDE2000 colour difference. With "Use fewer colors" on, k-means clustering groups the colours first and each group takes its nearest floss colour.
• Finished size = stitches ÷ count (inches) × 2.54 cm. On 14 count, 140 stitches are 10 inches or 25.4 cm. The fabric size adds the margin on every side.
• Skeins are an estimate: one cross stitch is taken to use (2√2 + 2) × cell size × 1.5 of thread for slack and ends, compared with the length one 8 m skein gives at the chosen strands (24 m with 2 strands), rounded up.
• Floss names and shades are approximations of similar colours and the codes are positions in this tool's list. The picture is processed in this browser on this device and is never uploaded.

How a photo becomes a cross stitch pattern

The picture is divided into as many columns as "Stitches across" and every cell takes the average colour of the pixels inside it. If lines of a drawing blur, turn on "Sharp edges (each cell takes its main color)" so a cell takes the colour that covers most of it instead of the average. Transparent pixels are left out of the average and a cell that is more than half empty stays empty.

Each cell colour is then replaced by the nearest colour in the floss chart. Colours are compared in the CIELAB space with the CIEDE2000 colour difference, which follows how the eye judges similar colours. With "Use fewer colors" on, k-means clustering groups the picture's colours into as many groups as "Most colors" allows, each group takes its nearest floss colour and only those colours are used. Dithering uses the Floyd–Steinberg method: the leftover difference of each cell is passed to its neighbours so dots of two colours mix into an in-between shade. Finally "Tidy small specks" merges isolated patches smaller than the chosen size into the colour around them.

Fixing a chart that looks wrong

A face or lettering that turns into a blur usually has too few cells. On 14 count, 80 stitches across are only 14.5 cm, so raise "Stitches across" to 120–150 or move to 18 count. With the same number of stitches, a higher count gives a smaller finished piece and the same chart.

If smooth areas look speckled, turn dithering off and raise "Tidy small specks" to 3 or 4; turn dithering on only to keep the gradients of a sky or skin. If removing the background also removes part of the subject, lower "How close to the background"; if background remains, raise it. For a dark photo, raising "Brightness" by 10 to 20 spreads the floss colours more evenly.

Questions and answers

How many colours does a cross stitch pattern from a photo need?

A photo is usually recognisable with 20 to 30 colours; a simple drawing needs 8 to 12. Lowering "Most colors" also lowers the number of skeins.

How do I work out the finished size on 14 count Aida?

Divide the stitches across by 14 for inches and multiply by 2.54 for centimetres. 112 stitches are 8 inches, about 20.3 cm. The page shows it under "Finished size".

How many skeins of floss should I buy?

The key lists the stitch count and estimated skeins for each colour. On 14 count with 2 strands the estimate is about 1,800 stitches per skein; real use depends on how you stitch, so allow one spare skein.

Can I print the chart on a black-and-white printer?

Set "Cells show" to "Symbols (black and white)": each cell then shows only its symbol and the key matches symbols to colours. On a colour printer, "Color and symbols" is easier to read.

What is backstitch?

A running line stitched with one strand over the finished crosses to outline shapes. With "Add backstitch (outline)" on, a bold line is drawn between cells that differ a lot in lightness and around the empty background, and its length is shown in cell sides.