Added more unit tests for ChannelPerceptualHash.

tests/statistics/channel-perceptual-hash/hu-phash.spec.ts

@@ -0,0 +1,47 @@
+/*
+  Copyright Dirk Lemstra https://github.com/dlemstra/magick-wasm.
+  Licensed under the Apache License, Version 2.0.
+*/
+
+import { ColorSpace } from '@src/enums/color-space';
+import { PixelChannel } from '@src/enums/pixel-channel';
+import { TestFiles } from '@test/test-files';
+
+describe('ChannelPerceptualHash#huPhash', () => {
+    it('should throw error for invalid colorspace', () => {
+        TestFiles.Images.fujiFilmFinePixS1ProJpg.use(image => {
+            const phash = image.perceptualHash();
+
+            let red = phash.getChannel(PixelChannel.Red);
+            red = expectToNotBeNull(red);
+
+            expect(() => red.huPhash(ColorSpace.HCL, 0)).toThrowError('Invalid color space specified');
+        });
+    });
+
+    it('should throw error for invalid channel index', () => {
+        TestFiles.Images.fujiFilmFinePixS1ProJpg.use(image => {
+            const phash = image.perceptualHash();
+
+            let red = phash.getChannel(PixelChannel.Red);
+            red = expectToNotBeNull(red);
+
+            expect(() => red.huPhash(ColorSpace.XyY, 7)).toThrowError('Invalid index specified');
+        });
+    });
+
+    it('should return the correct value', () => {
+        TestFiles.Images.fujiFilmFinePixS1ProJpg.use(image => {
+            const phash = image.perceptualHash();
+
+            let red = phash.getChannel(PixelChannel.Red);
+            red = expectToNotBeNull(red);
+
+            const huPhashXyY = red.huPhash(ColorSpace.XyY, 6);
+            expect(huPhashXyY).toBeCloseTo(9.1503);
+
+            const huPhashHSB = red.huPhash(ColorSpace.HSB, 6);
+            expect(huPhashHSB).toBeCloseTo(12.000);
+        });
+    });
+});

tests/statistics/channel-perceptual-hash/sum-squared-distance.spec.ts

@@ -0,0 +1,23 @@
+/*
+  Copyright Dirk Lemstra https://github.com/dlemstra/magick-wasm.
+  Licensed under the Apache License, Version 2.0.
+*/
+
+import { PixelChannel } from '@src/enums/pixel-channel';
+import { TestFiles } from '@test/test-files';
+
+describe('ChannelPerceptualHash#sumSquaredDistance', () => {
+    it('should return the distance', () => {
+        TestFiles.Images.fujiFilmFinePixS1ProJpg.use(image => {
+            const phash = image.perceptualHash();
+
+            let red = phash.getChannel(PixelChannel.Red);
+            let green = phash.getChannel(PixelChannel.Green);
+            red = expectToNotBeNull(red);
+            green = expectToNotBeNull(green);
+
+            const distance = red.sumSquaredDistance(green);
+            expect(distance).toBeCloseTo(32.1654);
+        });
+    });
+});

tests/statistics/channel-perceptual-hash/to-string.spec.ts

@@ -0,0 +1,21 @@
+/*
+  Copyright Dirk Lemstra https://github.com/dlemstra/magick-wasm.
+  Licensed under the Apache License, Version 2.0.
+*/
+
+import { PixelChannel } from '@src/enums/pixel-channel';
+import { TestFiles } from '@test/test-files';
+
+describe('ChannelPerceptualHash#toString', () => {
+    it('should return the correct value', () => {
+        TestFiles.Images.fujiFilmFinePixS1ProJpg.use(image => {
+            const phash = image.perceptualHash();
+
+            let red = phash.getChannel(PixelChannel.Red);
+            red = expectToNotBeNull(red);
+
+            const value = red.toString();
+            expect(value).toEqual('a329882b94893dc8af62621c88f098623beac1c9846fd61b208e63962ee061ab562ee0');
+        });
+    });
+});