nanoimg

The art of making image files incredibly small. Can be used to compress images drastically without losing too much quality. Can lead to reduction of sometimes over 90% compared to the original file size.

Installation

npm install nanoimg

Usage

import { nano } from 'nanoimg';

// Default settings
nano({
    inputFile: "in.png",
    outputFile: "out.png",
});

// or
const outputBuffer = await nano({
    inputBuffer: buffer,
});

// Custom settings
const options = {
  enableColorQuantization: true,
  colorTolerance: 10,
  enableAlphaStripping: false,
  enableAdaptiveFiltering: true,
  floidSteinbergDitheringLevel: 0,
  enableColorLimit: false,
  colorLimit: 256,
  enableQualityReduction: true,
  quality: 90,
};
nano({
    inputFile: "in.png",
    outputFile: "out.png",
    options: options,
});

Used techniques

• Color Quantization
• [To do] Color Averaging
• Image compression
• Adaptive row filtering
• Color palette limitation
• Removal of error diffusion

Results

Default settings

Average reduction of 50-70% compared to the original file size. Usually no visible loss of quality.

Very high

Average reduction of 90-95% compared to the original file size. Noticeable but not too bad loss of quality.

Extreme

Average reduction of 95-99% compared to the original file size. Visible loss of quality.

This is an example of what extreme compression can do to an image (97% reduction):

To do

• [ ] Color averaging
• [ ] Better tests
• [ ] More documentation
• [ ] Support for more output formats
• [x] Support for outputting to buffer
• [x] Support for inputting from buffer

License

This project is licensed under the MIT License - see the LICENSE file for details