Expose libvips recombination matrix operation #1477

test/unit/recomb.js

@@ -0,0 +1,131 @@
+'use strict';
+
+const assert = require('assert');
+
+const sharp = require('../../');
+const fixtures = require('../fixtures');
+
+describe('Recomb', function () {
+  it('applies a sepia filter using recomb', function (done) {
+    const output = fixtures.path('output.recomb-sepia.jpg');
+    sharp(fixtures.inputJpgWithLandscapeExif1)
+      .recomb([
+        [0.3588, 0.7044, 0.1368],
+        [0.299, 0.587, 0.114],
+        [0.2392, 0.4696, 0.0912]
+      ])
+      .toFile(output, function (err, info) {
+        if (err) throw err;
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(600, info.width);
+        assert.strictEqual(450, info.height);
+        fixtures.assertMaxColourDistance(
+          output,
+          fixtures.expected('Landscape_1-recomb-sepia.jpg')
+        );
+        done();
+      });
+  });
+
+  it('applies a sepia filter using recomb to an PNG with Alpha', function (done) {
+    const output = fixtures.path('output.recomb-sepia.png');
+    sharp(fixtures.inputPngAlphaPremultiplicationSmall)
+      .recomb([
+        [0.3588, 0.7044, 0.1368],
+        [0.299, 0.587, 0.114],
+        [0.2392, 0.4696, 0.0912]
+      ])
+      .toFile(output, function (err, info) {
+        if (err) throw err;
+        assert.strictEqual('png', info.format);
+        assert.strictEqual(1024, info.width);
+        assert.strictEqual(768, info.height);
+        fixtures.assertMaxColourDistance(
+          output,
+          fixtures.expected('alpha-recomb-sepia.png')
+        );
+        done();
+      });
+  });
+
+  it('applies a different sepia filter using recomb', function (done) {
+    const output = fixtures.path('output.recomb-sepia2.jpg');
+    sharp(fixtures.inputJpgWithLandscapeExif1)
+      .recomb([
+        [0.393, 0.769, 0.189],
+        [0.349, 0.686, 0.168],
+        [0.272, 0.534, 0.131]
+      ])
+      .toFile(output, function (err, info) {
+        if (err) throw err;
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(600, info.width);
+        assert.strictEqual(450, info.height);
+        fixtures.assertMaxColourDistance(
+          output,
+          fixtures.expected('Landscape_1-recomb-sepia2.jpg')
+        );
+        done();
+      });
+  });
+  it('increases the saturation of the image', function (done) {
+    const saturationLevel = 1;
+    const output = fixtures.path('output.recomb-saturation.jpg');
+    sharp(fixtures.inputJpgWithLandscapeExif1)
+      .recomb([
+        [
+          saturationLevel + 1 - 0.2989,
+          -0.587 * saturationLevel,
+          -0.114 * saturationLevel
+        ],
+        [
+          -0.2989 * saturationLevel,
+          saturationLevel + 1 - 0.587,
+          -0.114 * saturationLevel
+        ],
+        [
+          -0.2989 * saturationLevel,
+          -0.587 * saturationLevel,
+          saturationLevel + 1 - 0.114
+        ]
+      ])
+      .toFile(output, function (err, info) {
+        if (err) throw err;
+        assert.strictEqual('jpeg', info.format);
+        assert.strictEqual(600, info.width);
+        assert.strictEqual(450, info.height);
+        fixtures.assertMaxColourDistance(
+          output,
+          fixtures.expected('Landscape_1-recomb-saturation.jpg')
+        );
+        done();
+      });
+  });
+
+  describe('invalid matrix specification', function () {
+    it('missing', function () {
+      assert.throws(function () {
+        sharp(fixtures.inputJpg).recomb();
+      });
+    });
+    it('incorrect flat data', function () {
+      assert.throws(function () {
+        sharp(fixtures.inputJpg).recomb([1, 2, 3, 4, 5, 6, 7, 8, 9]);
+      });
+    });
+    it('incorrect sub size', function () {
+      assert.throws(function () {
+        sharp(fixtures.inputJpg).recomb([
+          [1, 2, 3, 4],
+          [5, 6, 7, 8],
+          [1, 2, 9, 6]
+        ]);
+      });
+    });
+    it('incorrect top size', function () {
+      assert.throws(function () {
+        sharp(fixtures.inputJpg).recomb([[1, 2, 3, 4], [5, 6, 7, 8]]);
+      });
+    });
+  });
+});