sharp/test/unit/colourspace.js

// Copyright 2013 Lovell Fuller and others.
// SPDX-License-Identifier: Apache-2.0

const assert = require('node:assert');

const sharp = require('../../');
const fixtures = require('../fixtures');

describe('Colour space conversion', function () {
  it('To greyscale', function (done) {
    sharp(fixtures.inputJpg)
      .resize(320, 240)
      .greyscale()
      .toFile(fixtures.path('output.greyscale-gamma-0.0.jpg'), done);
  });

  it('To greyscale with gamma correction', function (done) {
    sharp(fixtures.inputJpg)
      .resize(320, 240)
      .gamma()
      .grayscale()
      .toFile(fixtures.path('output.greyscale-gamma-2.2.jpg'), done);
  });

  it('Not to greyscale', function (done) {
    sharp(fixtures.inputJpg)
      .resize(320, 240)
      .greyscale(false)
      .toFile(fixtures.path('output.greyscale-not.jpg'), done);
  });

  it('Greyscale with single channel output', function (done) {
    sharp(fixtures.inputJpg)
      .resize(320, 240)
      .greyscale()
      .toColourspace('b-w')
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual(1, info.channels);
        assert.strictEqual(320, info.width);
        assert.strictEqual(240, info.height);
        fixtures.assertSimilar(fixtures.expected('output.greyscale-single.jpg'), data, done);
      });
  });

  it('From 1-bit TIFF to sRGB WebP', async () => {
    const data = await sharp(fixtures.inputTiff)
      .resize(8, 8)
      .webp()
      .toBuffer();

    const { format } = await sharp(data).metadata();
    assert.strictEqual(format, 'webp');
  });

  it('From CMYK to sRGB', function (done) {
    sharp(fixtures.inputJpgWithCmykProfile)
      .resize(320)
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual(true, data.length > 0);
        assert.strictEqual('jpeg', info.format);
        assert.strictEqual(320, info.width);
        done();
      });
  });

  it('From CMYK to sRGB with white background, not yellow', function (done) {
    sharp(fixtures.inputJpgWithCmykProfile)
      .resize(320, 240, {
        fit: sharp.fit.contain,
        background: 'white'
      })
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual('jpeg', info.format);
        assert.strictEqual(320, info.width);
        assert.strictEqual(240, info.height);
        fixtures.assertSimilar(fixtures.expected('colourspace.cmyk.jpg'), data, done);
      });
  });

  it('From profile-less CMYK to sRGB', function (done) {
    sharp(fixtures.inputJpgWithCmykNoProfile)
      .resize(320)
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual('jpeg', info.format);
        assert.strictEqual(320, info.width);
        fixtures.assertSimilar(fixtures.expected('colourspace.cmyk-without-profile.jpg'), data, done);
      });
  });

  it('Profile-less CMYK roundtrip', async () => {
    const [c, m, y, k] = await sharp(fixtures.inputJpgWithCmykNoProfile)
      .pipelineColourspace('cmyk')
      .toColourspace('cmyk')
      .raw()
      .toBuffer();

    assert.deepStrictEqual(
      { c, m, y, k },
      { c: 55, m: 27, y: 0, k: 0 }
    );
  });

  it('CMYK profile to CMYK profile conversion using perceptual intent', async () => {
    const data = await sharp(fixtures.inputTiffFogra)
      .resize(320, 240)
      .toColourspace('cmyk')
      .pipelineColourspace('cmyk')
      .withIccProfile(fixtures.path('XCMYK 2017.icc'))
      .raw()
      .toBuffer();

    const [c, m, y, k] = data;
    assert.deepStrictEqual(
      { c, m, y, k },
      { c: 1, m: 239, y: 227, k: 5 }
    );
  });

  it('CMYK profile to CMYK profile with negate', (done) => {
    sharp(fixtures.inputTiffFogra)
      .resize(320, 240)
      .toColourspace('cmyk')
      .pipelineColourspace('cmyk')
      .withIccProfile(fixtures.path('XCMYK 2017.icc'))
      .negate()
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual('tiff', info.format);
        assert.strictEqual(320, info.width);
        assert.strictEqual(240, info.height);
        fixtures.assertSimilar(
          fixtures.expected('colourspace.cmyk-to-cmyk-negated.tif'),
          data,
          { threshold: 0 },
          done
        );
      });
  });

  it('From sRGB with RGB16 pipeline, resize with gamma, to sRGB', function (done) {
    sharp(fixtures.inputPngGradients)
      .pipelineColourspace('rgb16')
      .resize(320)
      .gamma()
      .toColourspace('srgb')
      .toBuffer(function (err, data, info) {
        if (err) throw err;
        assert.strictEqual(320, info.width);
        fixtures.assertSimilar(fixtures.expected('colourspace-gradients-gamma-resize.png'), data, {
          threshold: 0
        }, done);
      });
  });

  it('Convert P3 to sRGB', async () => {
    const [r, g, b] = await sharp(fixtures.inputPngP3)
      .raw()
      .toBuffer();
    assert.strictEqual(r, 255);
    assert.strictEqual(g, 0);
    assert.strictEqual(b, 0);
  });

  it('Passthrough P3', async () => {
    const [r, g, b] = await sharp(fixtures.inputPngP3)
      .withMetadata({ icc: 'p3' })
      .raw()
      .toBuffer();
    assert.strictEqual(r, 234);
    assert.strictEqual(g, 51);
    assert.strictEqual(b, 34);
  });

  it('Invalid pipelineColourspace input', function () {
    assert.throws(function () {
      sharp(fixtures.inputJpg)
        .pipelineColorspace(null);
    }, /Expected string for colourspace but received null of type object/);
  });

  it('Invalid toColourspace input', function () {
    assert.throws(function () {
      sharp(fixtures.inputJpg)
        .toColourspace(null);
    });
  });
});