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    eth-signature-mark

    1.1.1 • Public • Published

    eth-signature-mark

    Generates a visual marker which can be embedded in a PNG image and then later translated into an Ethereum signature. The purpose of this library is to provide a simple way of adding an Ethereum signature to PNG files (for example, NFTs) so that identity information can be encoded directly in an image even if that image were to be downloaded.

    Sample

    Sample Signature Mark

    Generated by the following call: await drawSignatureMark('./sample.png', '0x21fbf0696d5e0aa2ef41a2b4ffb623bcaf070461d61cf7251c74161f82fec3a4370854bc0a34b3ab487c1bc021cd318c734c51ae29374f2beb0e6f2dd49b4bf41c', 0, 0, 100, 100);

    Installation

    # as a command-line tool
    npm install eth-signature-mark -g
    
    # as a library
    npm install eth-signature-mark --save

    Usage

    CLI

    # an Ethereum signature:
    SIG='0x21fbf0696d5e0aa2ef41a2b4ffb623bcaf070461d61cf7251c74161f82fec3a4370854bc0a34b3ab487c1bc021cd318c734c51ae29374f2beb0e6f2dd49b4bf41c'
    
    # get version
    eth-signature-mark -v
    
    # create a signature mark on a new image (250x250)
    eth-signature-mark --create './newImage.png' $SIG 0,0,50,50
    
    # create a signature mark on an existing image (30x30)
    eth-signature-mark --create './existingImage.png' $SIG
    
    # extract a signature mark from an image
    eth-signature-mark --extract './newImage.png' 0,0,50,50
    
    # extract a signature mark from an image
    eth-signature-mark --extract './existingImage.png'

    NodeJS Library

    const { drawSignatureMark, extractSignatureMark } = require('eth-signature-mark');
    
    // an Ethereum signature:
    const sig = '0x21fbf0696d5e0aa2ef41a2b4ffb623bcaf070461d61cf7251c74161f82fec3a4370854bc0a34b3ab487c1bc021cd318c734c51ae29374f2beb0e6f2dd49b4bf41c';
    
    // write a new PNG file (new file will be 500x500 in size):
    await drawSignatureMark('newImage.png' sig, 0, 0, 100, 100);)
    
    // write a signature mark on an existing file:
    // defaults to 6px by 6px cells starting at position (6, 6)
    await drawSignatureMark('existingImage.png', sig);
    
    // extract signature data from an existing image (also accepts x, y, width, height parameters).
    const checkSig = await extractSignatureMark('existingImage.png');
    
    assert.ok(sig === checkSig);

    Install

    npm i eth-signature-mark

    DownloadsWeekly Downloads

    2

    Version

    1.1.1

    License

    MIT

    Unpacked Size

    13.3 kB

    Total Files

    6

    Last publish

    Collaborators

    • stevenmhunt