Add brightness, saturation and hue modulation #609 (#1601)

test/fixtures/index.js

@@ -120,6 +120,8 @@ module.exports = {
   outputTiff: getPath('output.tiff'),
   outputZoinks: getPath('output.zoinks'), // an 'unknown' file extension
 
+  testPattern: getPath('test-pattern.png'),
+
   // Path for tests requiring human inspection
   path: getPath,
 

test/unit/modulate.js

@@ -0,0 +1,125 @@
+'use strict';
+
+const sharp = require('../../');
+const assert = require('assert');
+const fixtures = require('../fixtures');
+
+describe('Modulate', function () {
+  describe('Invalid options', function () {
+    [
+      null,
+      undefined,
+      10,
+      { brightness: -1 },
+      { brightness: '50%' },
+      { brightness: null },
+      { saturation: -1 },
+      { saturation: '50%' },
+      { saturation: null },
+      { hue: '50deg' },
+      { hue: 1.5 },
+      { hue: null }
+    ].forEach(function (options) {
+      it('should throw', function () {
+        assert.throws(function () {
+          sharp(fixtures.inputJpg).modulate(options);
+        });
+      });
+    });
+  });
+
+  it('should be able to hue-rotate', function () {
+    const base = 'modulate-hue-120.jpg';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
+
+    return sharp(fixtures.inputJpg)
+      .modulate({ hue: 120 })
+      .toFile(actual)
+      .then(function () {
+        fixtures.assertMaxColourDistance(actual, expected, 25);
+      });
+  });
+
+  it('should be able to brighten', function () {
+    const base = 'modulate-brightness-2.jpg';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
+
+    return sharp(fixtures.inputJpg)
+      .modulate({ brightness: 2 })
+      .toFile(actual)
+      .then(function () {
+        fixtures.assertMaxColourDistance(actual, expected, 25);
+      });
+  });
+
+  it('should be able to unbrighten', function () {
+    const base = 'modulate-brightness-0-5.jpg';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
+
+    return sharp(fixtures.inputJpg)
+      .modulate({ brightness: 0.5 })
+      .toFile(actual)
+      .then(function () {
+        fixtures.assertMaxColourDistance(actual, expected, 25);
+      });
+  });
+
+  it('should be able to saturate', function () {
+    const base = 'modulate-saturation-2.jpg';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
+
+    return sharp(fixtures.inputJpg)
+      .modulate({ saturation: 2 })
+      .toFile(actual)
+      .then(function () {
+        fixtures.assertMaxColourDistance(actual, expected, 30);
+      });
+  });
+
+  it('should be able to desaturate', function () {
+    const base = 'modulate-saturation-0.5.jpg';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
+
+    return sharp(fixtures.inputJpg)
+      .modulate({ saturation: 0.5 })
+      .toFile(actual)
+      .then(function () {
+        fixtures.assertMaxColourDistance(actual, expected, 25);
+      });
+  });
+
+  it('should be able to modulate all channels', function () {
+    const base = 'modulate-all.jpg';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
+
+    return sharp(fixtures.inputJpg)
+      .modulate({ brightness: 2, saturation: 0.5, hue: 180 })
+      .toFile(actual)
+      .then(function () {
+        fixtures.assertMaxColourDistance(actual, expected, 25);
+      });
+  });
+
+  describe('hue-rotate', function (done) {
+    [30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360].forEach(function (angle) {
+      it('should properly hue rotate by ' + angle + 'deg', function () {
+        const base = 'modulate-hue-angle-' + angle + '.png';
+        const actual = fixtures.path('output.' + base);
+        const expected = fixtures.expected(base);
+
+        return sharp(fixtures.testPattern)
+          .modulate({ hue: angle })
+          .toFile(actual)
+          .then(function () {
+            fixtures.assertMaxColourDistance(actual, expected, 25);
+          });
+      });
+    });
+  });
+});