Home › Photo check

Will This Photo Make a Workable Tattoo?

A photo is ready when it has enough pixels, enough tonal separation, a background that does not compete, and a subject that fills the frame. This page measures those four from the file, in this tab, and tells you which one to fix.

Quick answer: 1000 px on the long edge, the subject filling 45–85% of the frame, a background quieter than the subject, and clear light-to-dark separation. If a check fails, crop or reshoot before converting — a better input costs less than a redraw.

Choose a photo to checkJPG or PNG. Measured in this tab; the file is not uploaded.

Pick a file to see the four measurements.

What each check measures

All four are arithmetic on a 256 px copy of the image. “Strong edge” means a pixel whose Sobel gradient is in the top 20% of that copy.

Check	What is computed	Bands used here	What it tells you
Resolution	Longest pixel edge of the file	≥2000 plenty · 1000–1999 workable · 600–999 small · <600 too small	How much real detail the outline can trace
Contrast	Standard deviation of luminance on the 256 px copy, 0–255	≥40 good · 28–39 flat · <28 very flat	Whether subject and background separate in tone
Background	Strong-edge density in the outer 12% ring ÷ density in the middle 60% box	≤0.60 quiet · 0.60–0.85 some texture · >0.85 busy	Whether background objects will be read as part of the design
Subject in frame	Area of the box holding 90% of strong edges, or the box you drag	45–85% good · 25–44% small · <25% too little · >85% tight	How much of the frame the subject claims

These are heuristics. The bands were set by hand, not fitted to a labelled dataset, and nothing here predicts how a tattoo will heal. We sanity-checked the arithmetic on the site’s own sample photos and on synthetic edge cases — flat light, a noisy background, a small subject — which is enough to catch nonsense and not enough to call it accuracy.

What this page cannot tell you

Whether it will look like the subject. That is the conversion’s job, not the file’s. How much detail survives depends on the style you choose.
Whether your chosen size is possible. That is the needle-and-gap question; the seven handoff checks cover it.
How ink will read on your skin. The five skin-tone swatches in the try-on are screen approximations, not a prediction.
Sharpness. A 4000 px blurry photo scores at the top on resolution. Zoom to 100%: if the eyes or the letter edges are mush, they will not get sharper downstream.

Two fixes that solve most photos

Crop. A tight crop usually fixes background clutter and subject size at the same time, and it costs nothing.

Reshoot in even daylight. Put the light behind you rather than behind the subject, turn the flash off, and avoid a background with the same tone as the fur, hair or clothing. That is the practical fix for a flat contrast reading.

For angle, light and what to leave out of the frame, see photo tips.

Frequently asked

Does this page upload my photo?

No. The file is read into this tab and measured on a canvas; no request carries the image. The page still records a click event like the rest of the site, but not the photo. See the full data flow.

What resolution do I actually need?

1000 px on the long edge is workable for most line art; 600–999 px is enough for a bold silhouette only; under 600 px means the outline has to be invented. More pixels cannot fix flat light or a busy background.

Why does subject size matter?

A line drawing keeps the subject and drops most of the room. If the subject fills a quarter of the frame, the design is mostly room. 45–85% is the range where the conversion has enough subject to work with.

Is this an AI score?

No. It is four measurements with fixed bands: pixel dimensions, luminance spread, edge density in the border versus the middle, and the area of a subject box. There is no model and no training data. A high result is a better starting point, not a guarantee.

Next: the seven checks before a design goes to an artist · sizes by placement