pngv

A Rust library and CLI tool for converting PNG images to color matrices and reconstructing them as PNG or SVG files with 1x1 vector pixels.

Features

• Encode: Convert PNG images to JSON color matrices (.pngv format) where each cell contains a hex color with alpha channel (#RRGGBBAA)
• Decode: Reconstruct PNG images from .pngv files with 1x1 pixels
• SVG Export: Generate SVG files with 1x1 vector rectangles from .pngv files
• Simple CLI with automatic output path generation
• Can be used as a library in your own projects

Installation

As a CLI tool

cargo install pngv

As a library

Add this to your Cargo.toml:

[dependencies]
pngv = "0.1"

CLI Usage

The CLI requires a command and an input file. The output path is optional and will be auto-generated if not provided.

Basic syntax

pngv <COMMAND> <INPUT> [OUTPUT]

Commands

Encode: PNG → .pngv

Convert a PNG image to a color matrix:

pngv encode image.png
# Creates: image.pngv

pngv encode input.png output.pngv
# Creates: output.pngv

Decode: .pngv → PNG

Reconstruct a PNG from a color matrix:

pngv decode image.pngv
# Creates: image.png

pngv decode input.pngv output.png
# Creates: output.png

SVG: .pngv → SVG

Generate an SVG with 1x1 vector pixels:

pngv svg image.pngv
# Creates: image.svg

pngv svg input.pngv output.svg
# Creates: output.svg

Library Usage

use pngv::{encode_to_pngv, decode_from_pngv, decode_to_svg};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Encode a PNG to .pngv format
    encode_to_pngv("image.png", "image.pngv")?;
    
    // Decode back to PNG
    decode_from_pngv("image.pngv", "output.png")?;
    
    // Export to SVG
    decode_to_svg("image.pngv", "output.svg")?;
    
    Ok(())
}

.pngv Format

The .pngv file is a JSON array of arrays, where each element represents a pixel color:

[
  ["#FF0000FF", "#00FF00FF", "#0000FFFF"],
  ["#FFFFFFFF", "#000000FF", "#808080FF"]
]

• Each row represents a horizontal line of pixels (top to bottom)
• Each color is in #RRGGBBAA format (Red, Green, Blue, Alpha in hexadecimal)
• Alpha channel is fully supported

Use Cases

• Pixel art editing: Edit images as JSON matrices
• Image analysis: Process images as structured data
• Vector conversion: Convert pixel art to scalable SVG format
• Data visualization: Represent images as color data
• Backup/versioning: Store images in text-friendly format

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.