How to prepare a picture for a crochet graph
The quality of a crochet graph depends on the picture you start with. A grid of 24 to 80 stitches cannot hold the detail of a photo. These steps help a picture survive the conversion. They apply to the free graph maker and to flat single-crochet colorwork in general.
1. Crop tight
Crop to the subject in any photo app before you upload. Every stitch spent on empty background is a stitch not spent on the subject. The tool has no crop control, so crop first.
2. Raise contrast
Increase contrast and remove busy backgrounds. A dark subject on a light flat background converts cleanly. Soft gradients turn into patchy cells.
3. Choose few colors
Start with 2 to 4 colors. More colors mean more yarn changes and more weaving of ends. The tool supports 2 to 8 colors.
4. Size the grid to the detail
A simple icon works at 20 to 30 stitches wide. A face needs 60 or more. Use the size calculator to see what the grid means in inches at your gauge.
5. Fix it by hand
After conversion, paint over stray cells and use undo. Hand edits usually matter more than any setting.
6. Check the proportions
Stitches are wider than rows are tall in many gauges. Read the gauge guide so a round subject does not come out as an oval.
A chart is a color map, not a full pattern. Swatch first and test a small piece before committing a big project.