logo_converter

A Python tool to trim empty borders from images, leave a margin, and convert them into fixed aspect ratios (1.5 and 3.75) without distortion.

It works well for images with transparent backgrounds (e.g., logos, icons), but also supports opaque images with flat-color or white backgrounds.

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Features

• Content-aware trimming:
  • Uses transparency (alpha channel) if present.
  • Falls back to detecting flat background color from the corners.
• Margin control:
  • 1.5 ratio output keeps ~5% margin by default.
  • 3.75 ratio output keeps ~1% margin by default.
  • Both are configurable with separate flags.
• Aspect ratio correction:
  • Always pads (never crops or distorts) to reach the exact target ratio.
  • Ensures all content is preserved.
• Batch mode: Process a single file or an entire folder of images at once.
• Output naming:
  • Saves files as originalname_150ratio.png (for 1.5 ratio).
  • Saves files as originalname_375ratio.png (for 3.75 ratio).
• Format support:
  • PNG, JPEG/JPG, and SVG (requires CairoSVG).
  • Output is always PNG (to preserve alpha transparency).

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Installation

1. Clone the repo:

   git clone https://github.com/yourname/logo_converter.git
   cd logo_converter

2. (Optional but recommended) Create a virtual environment:

   python3 -m venv .venv
   source .venv/bin/activate

3. Install dependencies:

   pip install pillow cairosvg

   • Pillow: Image processing library
   • CairoSVG: Required for handling SVG input

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Usage

Convert a single image

python logo_converter.py logo.png

This will generate two files in the same folder:

• logo_150ratio.png (1.5 aspect ratio, ~5% margin)
• logo_375ratio.png (3.75 aspect ratio, ~1% margin)

Convert an entire folder

python logo_converter.py ./logos/

All supported images (.png, .jpg, .jpeg, .svg) in the folder will be converted.

Options

Option	Default	Description
--margin150	0.05	Margin fraction for 1.5 ratio output (e.g., 0.05 = 5%).
--margin375	0.01	Margin fraction for 3.75 ratio output (e.g., 0.01 = 1%).
--alpha-threshold	10	Alpha cutoff [0..255] for treating a pixel as "solid".
--corner-tol	12	Tolerance vs. corner background color.
--bg-white-threshold	245	Pixels above this are considered "near white" (likely background).
--pad-bg	white	Background for padding: "transparent", "white", or hex like "#333333".

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Example

Input: Meta_logo.png

python logo_converter.py Meta_logo.png --pad-bg transparent

Outputs:

• Meta_logo_150ratio.png (1.5 aspect ratio, ~5% margin, transparent padding)
• Meta_logo_375ratio.png (3.75 aspect ratio, ~1% margin, transparent padding)

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License

MIT License. See LICENSE for details.