AxisMend: Graph Digitizer

Turn charts into numbers you can inspect and reuse.

AxisMend is an offline workbench for recovering data from chart images and PDF pages. Import a source, define the axes, trace each series, review every point, then export the reconstructed dataset.

CALIBRATE THE CHART
Place axis anchors and enter their known values. Choose linear or logarithmic scaling for each axis. AxisMend shows calibration quality and residuals so you can identify uncertain setups before tracing.

TRACE WITH CONTROL
Use color-assisted tracing to follow plotted lines while keeping the result editable. Add multiple series, inspect gaps, and refine the trace when labels, gridlines, compression, or overlapping marks make pixels ambiguous.

REVIEW THE EVIDENCE
Zoom and pan across the chart, edit individual points, compare the canvas with the coordinate ledger, and inspect uncertainty. Interpolate or resample a series while preserving the original project for further correction.

EXPORT FOR THE NEXT STEP
Save reconstructed data as CSV or JSON, create SVG or PDF reports, or produce a portable project backup. Exports go only to the destination you choose.

PRIVATE BY DESIGN
All image processing, calibration, tracing, review, and export happen on your device. AxisMend has no network access, requests no Android permissions, and does not collect or share data. Imported sources and saved projects stay in app-private storage until you delete the project or uninstall the app.