Counted Thread

Your photograph, counted in thread

Your photograph stays in this browser, by policy

Or drop a photograph anywhere on the page. JPEG, PNG or WebP.

An Old English Sheepdog, white with a grey patch over one eye, in front of green leaves
The photograph. Old English Sheep Dog, Meredith Bannan, 2007, public domain.
The chart. Colours in DMC floss; symbols appear when a stitch is drawn large enough to read one.
60
24
Aida count
Page

Drawing the sample chart.

True size on the cloth, with a square to measure

The first page of the print file: the chart's grid at true size and, at the foot, the 50 mm square to measure
Page 1 of the print file, scaled to fit this screen. On paper it is the size of the cloth.

Every page is an SVG drawn in millimetres. Print it at Actual size (100%), never "fit to page", then measure the red square before the first stitch: it is 50 mm on each side. Rows and columns are numbered every 10 stitches across all pages, and red triangles mark the centre row and column.

    The Method

    A published formula, checked against its 34 test pairs

    From photograph to stitches

    The photograph is fitted to the stitches across you choose; the rows follow its shape. Every pixel whose centre falls inside a stitch counts once toward that stitch, averaged as light (linear sRGB, so a black-and-white fringe averages to the grey your eye sees) and then turned into CIELAB under the D65 white, with the sRGB matrix and white point Bruce Lindbloom publishes. A photograph larger than 2,400 pixels on its long side is first reduced to 2,400 by your browser.

    The colour cap

    The stitches' colours are grouped into at most the number of colours you set, by k-means clustering in CIELAB, seeded by k-means++ from a number computed from the photograph itself, so the same photograph always gives the same chart. The cap is a ceiling: a photograph with fewer colours gets fewer flosses.

    Matching to DMC floss

    Each colour takes the DMC six-strand floss nearest to it by the CIEDE2000 colour difference, in the form of G. Sharma, W. Wu and E. N. Dalal, "The CIEDE2000 color-difference formula: implementation notes, supplementary test data, and mathematical observations", Color Research and Application 30(1), 2005, with kL = kC = kH = 1. The largest colour chooses first. Two colours never share a floss: when a colour's nearest floss is taken, it gets its next nearest, and the legend marks it with an asterisk and names the floss it wanted.

    Lone stitches

    A stitch with no stitch of its own floss among its eight neighbours is a single stitch of colour, which stitchers call confetti. It takes whichever neighbouring floss is nearest, by CIEDE2000, to its own colour in the photograph. The rule runs once, every stitch judged on the chart as it stood before the pass, and the tally says how many stitches it changed. Untick "Merge lone stitches" to keep them.

    Symbols and pages

    Each floss gets one symbol, drawn as a path (letters, digits and simple marks; never a font glyph or an emoji), given out darkest floss first. The print file draws one stitch as 25.4 ÷ count millimetres: 1.814 mm on 14-count Aida, 1.588 mm on 16, 1.411 mm on 18.

    The receipts

    The CIEDE2000 code reproduces all 34 test pairs published by Sharma, Wu and Dalal to within 0.0001; the worst is pair 23, 1.00005 against 1.0000. The sRGB to CIELAB conversion matches six colours from Bruce Lindbloom's own calculator to within 0.01. The tests in the repository fix those tolerances before they run, along with the colour cap, the one-floss-per-colour rule, the confetti rule, the true size of the print file and the same chart from the same photograph.

    The photograph stays here

    Charting happens in your browser, in a background thread. Nothing is uploaded. This page's security policy allows a connection only back to this site, which serves static files and runs no code that could receive a photograph; your browser enforces that policy, whatever this page's code tried to do. This is the policy your browser received with this page:

    default-src 'self'; connect-src 'self'; img-src 'self' blob: data:

    Check it yourself: open your browser's developer tools, then Network, select this page, and read the Content-Security-Policy response header; or ask Mozilla's HTTP Observatory to read it.

    What the colours are, and are not

    A floss's colour here is an RGB approximation of dyed thread from a published table, the DMC floss data in craft-color-codes by MakeBead, under CC BY 4.0. The floss numbers and names are DMC's; the RGB values are that project's approximations. Dye lots vary, and thread on cloth reads darker than light on a screen. The chart is a guide: hold each floss against a real skein in daylight before you buy.

    Not built

    No backstitch, no half or quarter stitches, no PDF, no kits, no account. For woven cloth rather than stitched, Treadling draws the weaving draft; for the print of a hand itself, Painted Letters.