Added cannyEdge to MagickImage.

Author: dlemstra

src/magick-image.ts

@@ -658,6 +658,16 @@ export interface IMagickImage extends IDisposable {
      */
     brightnessContrast(brightness: Percentage, contrast: Percentage, channels: Channels): void;
 
+    /**
+     * Uses a multi-stage algorithm to detect a wide range of edges in images.
+     */
+    cannyEdge(): void;
+
+    /**
+     * Uses a multi-stage algorithm to detect a wide range of edges in images.
+     */
+    cannyEdge(radius: number, sigma: number, lower: Percentage, upper: Percentage): void;
+
     /**
      * Charcoal effect image (looks like charcoal sketch).
      */
@@ -2642,6 +2652,20 @@ export class MagickImage extends NativeInstance implements IMagickImage {
         });
     }
 
+    cannyEdge(): void;
+    cannyEdge(radius: number, sigma: number, lower: Percentage, upper: Percentage): void;
+    cannyEdge(radiusOrUndefined?: number, sigmaOrUndefined?: number, lowerOrUndefined?: Percentage, upperOrUndefined?: Percentage): void {
+        const radius = this.valueOrDefault(radiusOrUndefined, 0);
+        const sigma = this.valueOrDefault(sigmaOrUndefined, 1);
+        const lower = this.valueOrDefault(lowerOrUndefined, new Percentage(10)).toDouble() / 100;
+        const upper = this.valueOrDefault(upperOrUndefined, new Percentage(30)).toDouble() / 100;
+
+        this.useException(exception => {
+            const instance = ImageMagick._api._MagickImage_CannyEdge(this._instance, radius, sigma, lower, upper, exception.ptr);
+            this._setInstance(instance, exception);
+        });
+    }
+
     charcoal(): void;
     charcoal(radius: number, sigma: number): void;
     charcoal(radiusOrUndefined?: number, sigmaOrUndefined?: number): void {

tests/magick-image/canny-edge.spec.ts

@@ -0,0 +1,33 @@
+/*
+  Copyright Dirk Lemstra https://github.com/dlemstra/magick-wasm.
+  Licensed under the Apache License, Version 2.0.
+*/
+
+import { ErrorMetric } from '@src/enums/error-metric';
+import { Percentage } from '@src/types/percentage';
+import { TestFiles } from '@test/test-files';
+
+describe('MagickImage#cannyEdge', () => {
+    it('should change pixels of the image', () => {
+        TestFiles.Images.Builtin.logo.use(image => {
+            image.cannyEdge();
+
+            expect(image).toHavePixelWithColor(313, 288, '#fff');
+            expect(image).toHavePixelWithColor(314, 288, '#000');
+            expect(image).toHavePixelWithColor(466, 224, '#fff');
+            expect(image).toHavePixelWithColor(467, 224, '#000');
+        });
+    });
+
+    it('should use the correct default values', () => {
+        TestFiles.Images.Builtin.logo.use(image => {
+            image.clone(other => {
+                image.cannyEdge();
+                other.cannyEdge(0, 1, new Percentage(10), new Percentage(30));
+
+                const difference = other.compare(image, ErrorMetric.RootMeanSquared);
+                expect(difference).toBe(0);
+            })
+        });
+    });
+});