JSPM – @thi.ng/pixel-io-netpbm@0.1.16

Package Exports

@thi.ng/pixel-io-netpbm

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@thi.ng/pixel-io-netpbm) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

This project is part of the @thi.ng/umbrella monorepo.

About
- Status
Installation
Dependencies
API
Authors
License

About

Multi-format NetPBM reader & writer support for @thi.ng/pixel.

This package can read & write binary NetPBM image formats from byte arrays/buffers to @thi.ng/pixel pixel buffers (aka PackedBuffer).

Source format	Destination format	Rec. file extension⁽¹⁾
1 bit	`GRAY8`⁽²⁾	`.pbm`
2-8 bit grayscale	`GRAY8`	`.pgm`
9-16 bit grayscale	`GRAY16`	`.pgm`
24 bit RGB	`ARGB8888`	`.ppm`

⁽¹⁾ no relevance to actual parse/export logic ⁽²⁾ currently no support for actual 1-bit pixel buffers

Furthermore the parseHeader() function can be used to just extract image type, size and other meta data (from comments), without parsing the full image.

Status

ALPHA - bleeding edge / work-in-progress

Search or submit any issues for this package

Installation

yarn add @thi.ng/pixel-io-netpbm

// ES module
<script type="module" src="https://unpkg.com/@thi.ng/pixel-io-netpbm?module" crossorigin></script>

// UMD
<script src="https://unpkg.com/@thi.ng/pixel-io-netpbm/lib/index.umd.js" crossorigin></script>

Package sizes (gzipped, pre-treeshake): ESM: 1.31 KB / CJS: 1.39 KB / UMD: 1.49 KB

Dependencies

API

Generated API docs

import * as pbm from "@thi.ng/pixel-io-netpbm";
import * as fs from "fs";

const src = fs.readFileSync("a.pbm");
// <Buffer 50 34 0a 23 20 67 65 6e 65 72 61 74 65 64 20 62 79...>

// parse image header data
// P4 type => 1bit bitmap
pbm.parseHeader(src)
// {
//     type: 'P4',
//     width: 12,
//     height: 8,
//     max: undefined,
//     start: 47,
//     comments: [ 'generated by @thi.ng/pixel-io-netpbm' ]
// }

const img = pbm.read(src);
// PackedBuffer {
//   width: 12,
//   height: 8,
//   format: [Object],
//   pixels: Uint8Array(96) [
//     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
//     255, 255, 255,   0,   0, 255, 255, 255, 255, 255,   0, 255,
//     255, 255,   0,   0,   0,   0, 255, 255, 255,   0,   0, 255,
//     255,   0,   0, 255, 255,   0,   0, 255,   0,   0,   0, 255,
//     255,   0,   0,   0,   0,   0,   0, 255,   0,   0,   0, 255,
//     255,   0,   0, 255, 255,   0,   0, 255, 255,   0,   0, 255,
//     255,   0,   0, 255, 255,   0,   0, 255, 255, 255,   0, 255,
//     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255
//   ]
// }

// convert to RGB image and export w/ additional meta data
// (will be stored in PBM header comments)
fs.writeFileSync(
    "a-rgb.ppm",
    pbm.asPPM(
        img.as(RGB888),
        [
            "@prefix dc: http://purl.org/dc/terms/",
            "dc:created 2021-02-08",
            "dc:creator toxi"
        ]
    )
);

Authors

Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

@misc{thing-pixel-io-netpbm,
  title = "@thi.ng/pixel-io-netpbm",
  author = "Karsten Schmidt",
  note = "https://thi.ng/pixel-io-netpbm",
  year = 2021
}

@thi.ng/pixel-io-netpbm