CodeD.CSV2Heatmap

日本語 | English

This is a .NET library that generates heatmap images from 2D map data in CSV format. It is ideal for visualizing scientific measurement data such as surface roughness measurements, X‑ray focusing intensity distributions, and point‑cloud data.

Supported Data Formats:

• Grid Data (Height Map / Surface Map / Intensity Map / Raster Map)
• Point Cloud Data (XYZ Format / Scatter Data / Tabular XYZ Data)

Both grid‑based and XYZ‑based data structures are supported, enabling efficient image generation through fast parallel processing and SIMD optimization.

Features

• 📊 Supports multiple data formats: Grid Data and Point Cloud Data (XYZ Format)
• 🎨 Multiple color modes: Rainbow, Monochrome, Black‑Purple‑White
• 🚀 High performance: Parallel processing + SIMD‑optimized bitmap generation
• 🔧 Image processing utilities: Plane correction, rotation, trimming, and more
• 📈 Data conversion: Linear, logarithmic, and natural‑log scales
• 🔌 Powered by SkiaSharp: Cross‑platform graphics backend

Use Cases

• Surface roughness data (Surface Map / Height Map)
• X‑ray intensity distribution (Intensity Map / Raster Map)
• Visualization of temperature or concentration fields
• 2D projection of point‑cloud data
• Gridding and visualization of scattered data
• Any other 2D map (Grid / Raster) data

Installation

NuGet Package

dotnet add package CodeD.CSV2Heatmap

Manual Build

git clone https://github.com/dck-jp/CodeD.CSV2Heatmap.git
cd CodeD.CSV2Heatmap
dotnet build src/CodeD.CSV2Heatmap/CodeD.CSV2Heatmap.csproj -c Release

Requirements

• .NET Standard 2.0 or later

Dependencies

This library uses the following NuGet packages:

• SkiaSharp 2.88.8 or later - Cross-platform 2D graphics library for image generation and processing
• UTF.Unknown 2.5.1 - Character encoding detection library for CSV file parsing

Usage

For detailed usage examples and code samples, see docs/USAGE.md.

Supported File Formats

Grid Data (GridCSV / 2D Map Data)

Represents numerical data arranged in a grid—commonly used for surface roughness, X‑ray intensity, and raster data.

1.0  2.0  3.0  4.0
2.5  3.5  4.5  5.5
3.0  4.0  5.0  6.0

• Delimiters: Tab, comma, space
• Headers: Rows containing strings are treated as headers
• Data: Numeric rows only

Point Cloud Data (XYZ Format)

Contains X, Y, and Z values (multiple Z columns allowed).

X   Y   Z1    Z2    Z3
0   0   10.5  20.0  30.5
1   0   11.0  21.5  31.0
0   1   12.0  22.0  32.0

• Delimiters: Tab, comma, space
• Columns: X, Y, Z (multi‑value supported)
• Conversion: Automatically transformed into grid data

Note: Assumes regularly spaced grid points. Irregular point-cloud data may not interpolate correctly.

Performance

Optimizations used:

• Parallel processing
• SIMD acceleration (Vector)
• Asynchronous file I/O
• Memory‑efficient direct pixel access

Samples

Available in samples/:

• grid_sample_simple.txt
• grid_sample_temperature.csv
• xyz_sample.txt
• xyz_sample2.txt

See the samples/ folder for details.

Tests

cd tests/CodeD.CSV2Heatmap.Tests
dotnet test

Includes unit tests for:

• GridCsvParser
• XyzCsvParser
• HeatmapRenderer
• File-format parsing

License

Released under the MIT License. See LICENSE.

Contributing

Pull requests are welcome. For major changes, open an issue first.

Author

dck-jp

Changelog

See CHANGELOG.md for a detailed list of changes.

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