Replace-color-multicolor NPM

Replace Color

replace-color-multicolor was fork replace-color for add function multicolor and delta and Testcase already

Install

npm install --save replace-color-multicolor

Basic usage

replace-color-multicolor supports both Node.js error-first callbacks and promises. The package returns a Jimp's instance which you can use to execute some other image manipulations methods or save it with Jimp's write method.

Node.js error-first callback example

const replaceColor = require('replace-color')

replaceColor({
  image: './input.jpg',
  colors: [{
    type: 'hex',
    targetColor: '#FF0000',
    replaceColor: '#FFFFFF'
  }]
}, (err, jimpObject) => {
  if (err) return console.log(err)
  jimpObject.write('./output.jpg', (err) => {
    if (err) return console.log(err)
  })
})

Promise example

const replaceColor = require('replace-color')

replaceColor({
  image: './input.jpg',
  colors: [{
    type: 'hex',
    targetColor: '#FF0000',
    replaceColor: '#FFFFFF'
  }]
})
  .then((jimpObject) => {
    jimpObject.write('./output.jpg', (err) => {
      if (err) return console.log(err)
    })
  })
  .catch((err) => {
    console.log(err)
  })

API

replaceColor(options, callback)

options Object (required) - the options.
- image Buffer | Object | String (required) - an image being processed. It can be a buffer, Jimp's instance, a path to an image on your host machine or a URL address to an image on the internet. Please, take a look at the tests to understand all these options.
- colors Object (required) - the colors.
  - type String (required) - a targetColor and replaceColor type. Supported values are hex and rgb.
  - targetColor String | Array (required) - a color you want to replace. A 7-symbol string in case of hex type (e.g. #000000, #FFFFFF). An array of 3 integers from 0 to 255 in case of rgb type (e.g. [0, 0, 0], [255, 255, 255]).
  - replaceColor String | Array (required) - a new color which will be used instead of a targetColor color. A 7-symbol string in case of hex type (e.g. #000000, #FFFFFF). An array of 3 integers from 0 to 255 in case of rgb type (e.g. [0, 0, 0], [255, 255, 255]). You can also define a transparent channel for a replaceColor color. To achieve this, you can use a 9-symbol string in case of hex type (e.g. #00000000, #FFFFFFFF). Based on this Stack Overflow answer, an alpha channel is controlled by the first pair of digits in a hex code (e.g., 00 means fully transparent, 7F means 50%, FF means fully opaque). Also, you can use an array of 4 integers in case of rgb type. The first 3 integers must be from 0 to 255 and the last one must be from 0 to 1 (e.g., 0 means fully transparent, 0.5 means 50%, 1 means fully opaque).
- formula String (optional) - one of the three formulas to calculate the color difference. Supported values are E76, E94 and E00. The default value is E00 (the best algorithm).
- deltaE Number (optional) - a deltaE value which corresponds to a JND. The default value is 2.3. Please, read more about deltaE here. Generaly speaking, if the processed by the replace-color package image still has the watermarks, you should increase the deltaE value.
callback Function (optional) - a Node.js error-first callback.

Examples

Remove a watermark

Let's try to remove a watermark from this picture.

const replaceColor = require('replace-color')

replaceColor({
  image: 'https://i.imgur.com/XqNTuzp.jpg',
  colors: {
    type: 'hex',
    targetColor: '#FFB3B7',
    replaceColor: '#FFFFFF'
  },
  deltaE: 20
})
  .then((jimpObject) => {
    jimpObject.write('./output.jpg', (err) => {
      if (err) return console.log(err)
    })
  })
  .catch((err) => {
    console.log(err)
  })

Result

Example

Change a background color from a green to a blue one

Let's try to change a background color for this picture.

const replaceColor = require('replace-color')

replaceColor({
  image: 'https://i.imgur.com/aCxZpaq.png',
  colors: {
    type: 'hex',
    targetColor: '#66AE74',
    replaceColor: '#63A4FF'
  },
  deltaE: 10
})
  .then((jimpObject) => {
    jimpObject.write('./output.png', (err) => {
      if (err) return console.log(err)
    })
  })
  .catch((err) => {
    console.log(err)
  })

Result

Example

Change a background color from a green to a transparent one (using `hex` type)

Let's try to change a background color for this picture.

const replaceColor = require('replace-color')

replaceColor({
  image: 'https://i.imgur.com/aCxZpaq.png',
  colors: {
    type: 'hex',
    targetColor: '#66AE74',
    replaceColor: '#00000000'
  },
  deltaE: 10
})
  .then((jimpObject) => {
    jimpObject.write('./output.png', (err) => {
      if (err) return console.log(err)
    })
  })
  .catch((err) => {
    console.log(err)
  })

Result

Example

Change a background color from a green to a 50% transparent green (using `rgb` type)

Let's try to change a background color for this picture.

const replaceColor = require('replace-color')

replaceColor({
  image: 'https://i.imgur.com/aCxZpaq.png',
  colors: {
    type: 'rgb',
    targetColor: [102, 174, 116],
    replaceColor: [102, 174, 116, 0.5]
  },
  deltaE: 10
})
  .then((jimpObject) => {
    jimpObject.write('./output.png', (err) => {
      if (err) return console.log(err)
    })
  })
  .catch((err) => {
    console.log(err)
  })

Result

Example

Error handling

To indicate the replace-color's errors you should use the err instanceof replaceColor.ReplaceColorError class.

replaceColor({}, (err, jimpObject) => {
  if (err instanceof replaceColor.ReplaceColorError) {
    //  A replace-color's error occurred. 
  } else if (err) {
    // An unknown error occurred.
  }
  
  // Everything went fine.
})

A replace-color's error instance has the code and field properties. For now, the package has two codes: PARAMETER_INVALID and PARAMETER_REQUIRED. The field property shows which exact property was not passed or is invalid using the glob notation (e.g. options.colors.type). Please, take a look at the tests to see all the possible cases.