Added extractArea to the MagickReadSettings.

src/settings/magick-read-settings.ts

@@ -5,6 +5,7 @@
 
 import { Disposable } from '../internal/disposable';
 import { ImageMagick } from '../image-magick';
+import { MagickGeometry } from '../types/magick-geometry';
 import { MagickSettings } from './magick-settings';
 import { NativeMagickSettings } from './native-magick-settings';
 import { _withString } from '../internal/native/string';
@@ -20,6 +21,11 @@ export class MagickReadSettings extends MagickSettings {
         Object.assign(this, partialSettings);
     }
 
+    /**
+     * Gets or sets the specified area to extract from the image.
+     */
+    extractArea?: MagickGeometry;
+
     /**
      * Gets or sets the height.
      */
@@ -41,6 +47,12 @@ export class MagickReadSettings extends MagickSettings {
             });
         }
 
+        if (this.extractArea !== undefined) {
+            _withString(this.extractArea.toString(), extractAreaPtr => {
+                ImageMagick._api._MagickSettings_Extract_Set(settings._instance, extractAreaPtr);
+            });
+        }
+
         return Disposable._disposeAfterExecution(settings, func);
     }
 

tests/settings/magick-read-settings/extract-area.spec.ts

@@ -0,0 +1,35 @@
+/*
+  Copyright Dirk Lemstra https://github.com/dlemstra/magick-wasm.
+  Licensed under the Apache License, Version 2.0.
+*/
+
+import { ImageMagick } from '@src/image-magick';
+import { MagickGeometry } from '@src/types/magick-geometry';
+import { MagickReadSettings } from '@src/settings/magick-read-settings';
+import { MagickColor } from '@src/magick-color';
+
+describe('MagickReadSettings#extractArea', () => {
+    it('should only read the specified area of the image', () => {
+        const settings = new MagickReadSettings();
+        settings.extractArea = new MagickGeometry(350, 260, 100, 100);
+
+        ImageMagick.read('logo:', settings, (image) => {
+            expect(image.width).toBe(100);
+            expect(image.height).toBe(100);
+
+            expect(image).toHavePixelWithColor(0, 0, new MagickColor('#223e92ff'));
+        });
+    });
+
+    it('should not outside the image', () => {
+        const settings = new MagickReadSettings();
+        settings.extractArea = new MagickGeometry(600, 400, 100, 100);
+
+        ImageMagick.read('logo:', settings, (image) => {
+            expect(image.width).toBe(40);
+            expect(image.height).toBe(80);
+
+            expect(image).toHavePixelWithColor(0, 0, new MagickColor('#fff'));
+        });
+    });
+});