Excel Pixel Art

Convert images to Excel pixel art and back. Each cell becomes a pixel with its background colour matching the original image.

Installation

pip install excel-pixel-art

Or install from source:

git clone https://github.com/luigipascal/excelart.git
cd excelart
pip install -e .

Usage

Convert Image to Excel

image2xlsx photo.png
image2xlsx photo.png -o output.xlsx
image2xlsx photo.png --max-size 150

Options:

• -o, --output: Output Excel file path (default: <input>_excel.xlsx)
• --max-size: Maximum dimension in cells (default: 100)

Convert Excel Back to Image

xlsx2image output.xlsx
xlsx2image output.xlsx -o recovered.png
xlsx2image output.xlsx --sheet Sheet1

Options:

• -o, --output: Output image path (default: <input>_reconstructed.png)
• --sheet: Worksheet name to use (default: 'Image' if present, else active)
• --background R,G,B: Background colour for missing cells (default: 0,0,0)
• --no-autocrop: Disable auto-crop to solid-fill bounds

QA & Verification

# Compare with original for fidelity check
xlsx2image output.xlsx --compare original.png

# Generate visual diff heatmap
xlsx2image output.xlsx --compare original.png --diff-image diff.png

# CI pass/fail with threshold
xlsx2image output.xlsx --compare original.png --diff-threshold 5

Python API

from excel_pixel_art import image_to_excel, excel_to_image, compare_images

# Convert image to Excel
image_to_excel("photo.png", "output.xlsx", max_size=100)

# Convert back
excel_to_image("output.xlsx", "recovered.png")

# Compare for QA
compare_images("photo.png", "recovered.png", diff_output="diff.png", diff_threshold=5)

How It Works

1. Image → Excel: The image is resized to fit within max_size cells, maintaining aspect ratio. Each pixel becomes a cell with a solid fill colour matching the RGB value.

2. Excel → Image: Cells with solid fills are read back, extracting their ARGB colour values. Auto-crop detects the actual pixel bounds, ignoring stray formatting.

3. QA Tools: The fidelity report compares reconstructed images against originals, with optional diff heatmaps and threshold-based pass/fail for CI integration.

Features

• ARGB colour handling - Proper Excel colour format (no transparency bugs)
• Fill caching - Fast generation even for images with thousands of unique colours
• Auto-crop - Ignores stray formatting outside the pixel grid
• Robust extraction - Handles both fgColor and start_color patterns
• CI-friendly - Threshold-based pass/fail for automated testing

License

MIT