Heatmap Digitizer

Heatmap Digitizer is a Swift-based macOS app designed to digitize heatmaps/density maps efficiently using KDTree for spatial queries. The app allows users to extract data points from an image of a heatmap and save the results as a CSV file for further analysis.

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Purpose

This app is designed to:

• Digitize heatmaps with high efficiency.
• Provide an intuitive interface for aligning axes and colorbars.
• Export digitized data in a structured format.

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Features

1. Load an image of a heatmap for processing.
2. Align the axes and colorbar to map image coordinates to real-world data values.
3. Efficiently digitize the heatmap using KDTree for nearest-neighbor queries.
4. Export the digitized data as a CSV file.

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Usage

1. Load an Image

• Open the app and load the heatmap image you want to digitize.

2. Align Axes

• Select the lower-left corner of the heatmap and click. A red dot will appear at the selected point.
• Select the lower-right corner of the heatmap and click. Another red dot will appear.
• Select the upper-left corner of the heatmap and click. A third red dot will appear.
• Make sure to select the points in this order: lower-left, lower-right, upper-left.

3. Align Colorbar

• Select the lower limit of the colorbar and input its lower bound value. A blue dot will appear at the selected point.
• Select the upper limit of the colorbar and input its upper bound value. Another blue dot will appear.
• Ensure you select the points in this order: lower limit, upper limit.

4. Digitize the Heatmap

• Once the axes and colorbar are aligned, proceed with digitizing the heatmap.
• The digitized result will be saved automatically as a CSV file in your home folder.

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Output

The output CSV file will contain the Value Matrix: The corresponding data matrix for each point.

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Requirements

• macOS: 11.0 or later
• Swift: Built using Swift and KDTree for efficient digitization.

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Future Enhancements

• Support for additional heatmap formats.
• Option to select points without following this order.
• Export data in multiple file formats (e.g., JSON, Excel).

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Support

For issues, suggestions, or feedback, please contact shihuamingzhi'at'gmail.com. You can create a pull request if you would like to implement new features.