fast-bmp

Maintained by Zakodium

A library for encoding and decoding bmp image file format. References:

• Wikipedia BMP format page
• Microsoft BMPV5 format page

Supported features

This library only supports V5 headers.

• binary (1-bit per pixel)
• greyscale (8-bits per pixel)
• RGB (24-bits per pixel)
• RGBA (32-bits per pixel)

Usage

Encoding

import { encode } from 'fast-bmp';

// 0 0 0 0 0
// 0 1 1 1 0
// 0 1 0 1 0
// 0 1 1 1 0
// 0 0 0 0 0
const data = new Uint8Array([
  0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0,
]);
const imageData = {
  width: 5,
  height: 5,
  data,
  bitsPerPixel: 1,
  components: 1,
  channels: 1,
};
// Encode returns a Uint8Array.
const encoded = encode(imageData);
fs.writeFileSync('image.bmp', encoded);

Decoding

import { decode } from 'fast-bmp';

// 0 0 0 0 0
// 0 1 1 1 0
// 0 1 0 1 0
// 0 1 1 1 0
// 0 0 0 0 0
const buffer = fs.writeFileSync('image.bmp');
const imageData = decode(buffer);
/* Returns object:
{
width: 5,
height: 5,
data: new Uint8Array([
    0, 0, 0, 0, 0, 
    0, 1, 1, 1, 0, 
    0, 1, 0, 1, 0, 
    0, 1, 1, 1, 0, 
    0, 0, 0, 0, 0,
  ]),
bitsPerPixel: 1,
components: 1,
channels: 1,
colorMasks: [0x00ff0000, 0x0000ff00, 0x000000ff],
compression: 0,
xPixelsPerMeter: 2835,
yPixelsPerMeter: 2835,
}
*/