Release Notes

VectorGraph Changelog

All notable changes to VectorGraph — the browser-based professional graph digitizer, chart data extractor, and data analysis platform. Updated with each release.

v2.0.0 28 Jun 2026

Platform Evolution — Math Tools, Combined Export & Full Workspace Overhaul

New
  • Combined PDF Export — New export mode generates a single PDF containing the source chart image, extracted data chart visualization, and full data table side by side. Perfect for documentation and audit trails.
  • Advanced Math Tab — Calculus Engine — Full calculus toolkit added: dy/dx Derivative computation with Save-as-New, True Polar Area integration for polar/radar data, and ∫ Area under curve via trapezoidal integration.
  • Bar Chart Delta Analysis — New Bar Math feature: compute sequential changes or group-comparison deltas across extracted bar series.
  • Pareto / Cumulative Sum — One-click Pareto chart generation from extracted bar data. Exports as a new curve alongside original bars.
  • SVG Chart Export — Export the extracted data chart as a scalable SVG vector file directly from the Data Inspector toolbar.
  • PNG Chart Export with Aspect Ratio — High-DPI PNG export with selectable aspect ratio (Free, 16:9, 4:3, 1:1).
  • Pie-of-Pie Sub-Chart Extraction — Compound pie chart support: assign extracted segments as sub-slices of a parent slice. Full export support.
  • Dominant Color Palette Analyzer — Auto-analyze the uploaded chart image and extract its dominant color palette. Click any dominant color to instantly set it as the extraction target.
  • Custom X-Values Sampling — Pixel Harvest tool now supports user-supplied custom X coordinates for targeted data point extraction at specific locations.
  • Workspace Folder Drag-and-Drop — Projects can now be dragged between workspace folders directly in the sidebar.
Improved
  • Data Inspector Table — Added inline cell editing, multi-row selection, column sorting, and keyboard navigation between cells.
  • Excel XLSX Export — Now generates fully formatted multi-sheet workbooks: summary chart sheet + one sheet per extracted curve with proper headers, curve metadata, and color coding.
  • Polar Wedge Scan — Added continuous mask-based tracing mode (toggle between snap-to-spokes and freeform continuous tracing).
  • Image Enhancement — Added CLAHE (Contrast-Limited Adaptive Histogram Equalization) for low-contrast scientific and scanned charts.
  • Performance — Extraction algorithms fully offloaded to Web Worker. Main thread remains responsive during all processing operations.
Fixed
  • Logarithmic axis calibration was incorrectly applying linear interpolation in some edge cases — now uses full log-space distance calculation.
  • Calibration pin positions failed to recalculate correctly after fine rotation (deskew) was applied — now updates automatically.
  • Bar chart horizontal orientation exported X/Y values transposed in some configurations.
  • Large PDF files (>20 MB) caused out-of-memory errors — resolved with streaming page render pipeline.
Security
  • CSV exports now sanitize formula-injection characters in all user-controlled fields (project name, curve name, axis labels).
  • HTTP security headers added: X-Content-Type-Options, X-Frame-Options, Referrer-Policy.
v1.3.1 23 Jun 2026

Stability & Polish — Bug Fixes and UX Refinements

Improved
  • Eyedropper Color Pick — Color tolerance slider now shows live pixel match count updating in real-time as tolerance is adjusted. Helps users find the right threshold faster.
  • Calibration Warnings — Added inline warning messages when calibration points may be invalid (coincident, collinear) before the user clicks Apply.
  • Stylus Settings Panel — Added dedicated Apple Pencil / stylus pressure sensitivity controls in the Calibrate tab for iPad users.
  • Onboarding Tour — Tour steps now highlight the exact UI element being described with an animated glow ring.
  • Mobile Sidebar — Project sidebar now uses a slide-in drawer with backdrop on mobile/tablet, instead of overlapping the canvas.
Fixed
  • ROI freehand mask had a 1-pixel gap at the start/end of the stroke on some devices.
  • Pie chart segment assignment was lost when switching back from a different project and returning.
  • Polynomial fitting panel showed an incorrect R² value when applied to sparse data sets (<5 points).
  • The image crop modal did not properly restore the original image when the user clicked Cancel.
  • Auto-tolerance was resetting to manual mode on project reload.
v1.3.0 19 Jun 2026

Polar & Radar/Spider Charts — Full Radial Data Extraction

New
  • Polar Chart Support — New project type for polar coordinate charts. Radial calibration with configurable origin value, max value, and ring count. Full extraction and export support.
  • Radar / Spider Chart Support — Full radar/web/spider chart extraction. Configure 3–16 spoke axes with custom labels. Polar Wedge Scan algorithm sweeps radially from the center to extract values at each spoke.
  • Polar Calibration System — New CALIBRATE tab mode for polar/radar charts: set center origin, outer ring value, spoke count, and angular direction. Supports clockwise and anticlockwise spoke ordering.
  • Custom Radial Scale Modes — Four radial scale modes: Max Value (simple), Two Rings (interpolated from two known rings), Two Points (from two measured values), Custom CSV (comma-separated ring values from center).
  • Spoke Label Input — Assign custom text labels to each spoke axis directly in the Data Inspector. Labels are included in all exports.
  • Polygon Fill Rendering — Optional filled polygon rendering in the Data Inspector chart preview for radar series. Configurable per-series.
  • Polar Area Integration — Math tab ∫ Area function now computes the true geometric polar area for radar/polar chart data.
  • Polar Wedge Scan Algorithm — New extraction algorithm using radial wedge sweeping from chart center. Configurable spoke snapping and gap-bridge for dashed lines.
Improved
  • Chart Group System — ChartGroups now support per-group color assignment, locking, visibility toggling, and polygon fill control.
  • Data Inspector — Radar chart data is grouped by spoke/series with spoke labels shown as column headers.
Fixed
  • Polar Wedge Scan returned incorrect angles when the chart image was rotated using the deskew tool.
  • Spoke angle detection failed on charts with fewer than 4 spokes.
v1.2.0 13 Jun 2026

Bar Charts, Histograms & Complete Export Suite

New
  • Bar Chart & Histogram Project Type — New project type supporting vertical and horizontal bar charts, grouped and stacked bar series, and continuous frequency histograms.
  • Auto Bar Extraction Tool — Single-click bar detection and height measurement. Automatically identifies bar boundaries, groups by color, and produces well-formatted labeled output.
  • Histogram Mode — Dedicated histogram extraction: detects bin widths, class intervals, and frequency values. Exportable as class interval table.
  • DXF Export (AutoCAD) — Export any extracted curve or chart as an AutoCAD-compatible DXF vector file. Supports all chart types.
  • PDF Report Export — Professional paginated PDF report with embedded ECharts chart visualization and extracted data table.
  • Bar Statistics Panel — Math tab now includes bar-specific analysis: Sum, Mean, Median, Mode, Min, Max, Std Dev, and visual display.
  • Grouped Bar Chart Support — Each color group in a bar chart is extracted as a separate named series. Groups are auto-organized and color-coded to match the original chart exactly.
  • K-Means Color Cluster Algorithm — New advanced extraction algorithm for charts with complex or multi-color backgrounds. Clusters image pixels by color to isolate target curves.
  • Blob Detector Algorithm — Scatter plot marker detection algorithm. Identifies and centers on discrete data point blobs by shape analysis.
Improved
  • Color Tolerance — Eyedropper color tolerance slider now shows pixel match count live, updated via debounced WebWorker analysis.
  • ROI Masking — Added Freehand brush mask type with configurable brush size. Added Ellipse mask type.
  • Project Sidebar — Folders now support drag-and-drop project reordering within the same folder.
Fixed
  • Large images (>8000px wide) caused the ROI mask to misalign from the canvas rendering.
  • JSON export included extra fields for calibration data that should not appear in user-facing output.
  • CSV export was using semicolon as separator in some locales — now always uses comma with UTF-8 encoding.
v1.1.0 07 Jun 2026

Data Inspector, Math Tools & Image Enhancement

New
  • Data Inspector Panel — New dedicated inspection panel with editable data table and live ECharts chart preview. Replaces the old static data view.
  • Inline Data Editing — Edit any extracted (X,Y) value directly in the Data Inspector table. Changes immediately reflect in the live chart preview.
  • Math Tab — Moving Average — Apply smoothing to any extracted curve using a configurable window size (2–30 points). Save result as a new curve or overwrite.
  • Math Tab — Polynomial Fitting — Fit a polynomial curve of degree 1–8 to extracted data. View equation coefficients. Save as new curve.
  • Math Tab — Peak Detection — Detect local maxima and minima in extracted curves with configurable prominence threshold. Results include (X,Y) coordinates of each peak/trough.
  • Math Tab — Descriptive Statistics — Compute count, X/Y range, mean, standard deviation, and area under curve for any extracted series.
  • Image Crop Tool — New crop modal for trimming chart borders before calibration. Non-destructive.
  • Advanced Image Filters — Added Grayscale, Sharpen, Invert Colors, Denoise (Gaussian smooth), and Binarize (pure black & white with threshold slider) filters to the Image tab.
  • Fine Rotation / Deskew Slider — ±45° rotation slider for correcting tilted or skewed chart scans.
  • Gridline Removal — Morphological open/close operations to remove horizontal and vertical chart gridlines before extraction. Auto-detect grid color button.
  • Excel XLSX Export — First version of Excel export with basic multi-column data sheet.
Improved
  • Image Tab — Reorganized with collapsible Advanced Filters section. Image upload now shows drag-and-drop zone with visual feedback.
  • Calibration — Added axis name and unit fields (e.g., “Time (ms)”, “Voltage (V)”) that are included in exports.
  • Eyedropper — Added auto-tolerance detection that automatically computes optimal color distance threshold.
Fixed
  • Calibration Apply button was accessible even when fewer than 2 points were placed — now properly disabled.
  • Image brightness/contrast sliders were not persisted when switching between projects.
  • ROI polygon mask had incorrect hit-testing on high-DPI (retina) displays.
v1.0.0 01 Jun 2026

Initial Public Release — Line, Scatter & Pie Charts

New
  • Line Chart Extraction — Auto Trace algorithm for continuous line curves using Averaging Window technique. Configurable strip width and merge window.
  • Scatter Plot Extraction — X-Step Interpolated algorithm for regular-interval sampling with sub-pixel cubic spline interpolation.
  • Pie & Donut Chart Extraction — Segment angle measurement from center pin. Configurable total value (percentage or absolute). Donut charts supported via inner radius setting.
  • 3-Point & 4-Point Axis Calibration — Place calibration pins on known coordinate values. Affine transformation (Cramer’s Rule) maps every pixel to real coordinates.
  • Linear & Logarithmic Axes — Support for Linear X/Y, Log-Log (both axes), and Semi-Log (single axis) coordinate systems.
  • Eyedropper Color Selection — Click to capture target color from the chart. Configurable color distance tolerance.
  • Region of Interest (ROI) Masking — Restrict extraction to a specific area using Rectangle and Polygon mask drawing tools.
  • Multi-Project Workspace — Create and organize multiple projects in the sidebar. Data persisted to browser IndexedDB (Dexie.js).
  • Project Folders — Group projects into named folders for organization.
  • CSV Export — Export extracted data as UTF-8 encoded comma-separated values.
  • JSON Export — Export as structured JSON array of coordinate objects.
  • XML Export — Export as standard XML data document.
  • Offline First — Service worker caches the app after first load. All processing runs locally via WebAssembly (OpenCV.js). No server uploads.
  • Zhang-Suen Skeleton Algorithm — Advanced extraction option for thick or overlapping lines. Reduces thick lines to 1-pixel topological skeletons.
  • Frangi Ridge Filter — Vessel-like line structure detection algorithm for noisy or low-contrast charts.
  • Hessian Maxima — Auto-traces continuous lines by following ridge peak positions.
  • Interactive Onboarding Tour — 12-step guided tour highlights every major feature for new users.
  • Interactive Guide Book — In-app guide with 6 topic categories, live diagrams, and swipe navigation.
  • Clipboard Paste — Paste a chart image directly from clipboard (Ctrl+V / Cmd+V).

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