FigureLab: a browser-based tool for assembling publication-quality scientific figures

Abstract

FigureLab is a single-file, browser-based application for assembling publication-quality scientific figures from image data (microscopy, western blots, histology, gels, and clinical or specimen photographs). It runs entirely client-side with no installation, server, or internet connection required, so no image data ever leaves the user's computer. Features include grid layout with drag-to-space gutters, per-panel image adjustments (brightness, contrast, gamma, levels, fluorescence LUTs, and multi-channel composites), two-point scale-bar calibration, an annotation system with undo/redo, and export to PNG, JPEG, WebP, TIFF, PDF, and SVG at publication DPI (up to 1200 dpi for line art). A freeform editor adds vector data charts (bar, line, scatter, box, violin, beeswarm, heatmap, and Kaplan-Meier survival curves) drawn from pasted or CSV data, flowcharts with anchored connectors including PRISMA/CONSORT/fishbone templates, base-pair-scaled gene maps and genetic circuits in SBOL Visual notation (linear or circular, with GenBank/FASTA import), and a recolourable scientific-icon library. Measurements read the retained native samples of 16-bit and floating-point TIFF imports, reporting absolute intensity at the acquisition bit depth rather than the 8-bit display, and disclose per result when they fall back to the display. Scientific-integrity safeguards are built in: no p-value or statistical inference is ever computed, pixel edits are non-destructive overlays, and AI-generated content is disclosed. It also exports reproducibility scripts (R/Python, including chart code), CSV panel metadata, and journal-style captions.