feat: implement sliceBrief

Author: opatiny

scripts/featureMatching/featureMatchingTest.ts

@@ -17,7 +17,7 @@ import { GetColorsOptions } from '../../src/featureMatching/utils/getColors';
 import { getMinMax } from '../../src/utils/getMinMax';
 
 import util from 'util';
-import { sliceBrief } from './sliceBrief';
+import { sliceBrief } from '../../src/featureMatching/descriptors/utils/sliceBrief';
 util.inspect.defaultOptions.depth = 5;
 
 const getBriefOptions: GetBriefOptions = {

src/featureMatching/descriptors/utils/__tests__/sliceBrief.test.ts

@@ -0,0 +1,49 @@
+import { ImageColorModel } from '../../../../Image';
+import { getOrientedFastKeypoints } from '../../../keypoints/getOrientedFastKeypoints';
+import { getBriefDescriptors } from '../../getBriefDescriptors';
+import { sliceBrief } from '../sliceBrief';
+
+test('default options', () => {
+  const image = testUtils
+    .load(`featureMatching/polygons/polygon.png`)
+    .convertColor(ImageColorModel.GREY)
+    .invert();
+
+  const keypoints = getOrientedFastKeypoints(image);
+
+  const brief = getBriefDescriptors(image, keypoints);
+
+  const result = sliceBrief(brief);
+
+  expect(result).toStrictEqual(brief);
+});
+
+test('slice 0 to 3', () => {
+  const image = testUtils
+    .load(`featureMatching/polygons/polygon.png`)
+    .convertColor(ImageColorModel.GREY)
+    .invert();
+
+  const keypoints = getOrientedFastKeypoints(image);
+
+  const brief = getBriefDescriptors(image, keypoints);
+
+  const result = sliceBrief(brief, { end: 3 });
+
+  expect(result.descriptors.length).toBe(3);
+});
+
+test('range error', () => {
+  const image = testUtils
+    .load(`featureMatching/polygons/polygon.png`)
+    .convertColor(ImageColorModel.GREY)
+    .invert();
+
+  const keypoints = getOrientedFastKeypoints(image);
+
+  const brief = getBriefDescriptors(image, keypoints);
+
+  expect(() => sliceBrief(brief, { start: -1 })).toThrow(
+    'start or end are out of range',
+  );
+});

scripts/featureMatching/sliceBrief.ts renamed to src/featureMatching/descriptors/utils/sliceBrief.ts

@@ -1,5 +1,4 @@
-import { option } from 'yargs';
-import { Brief } from '../../src/featureMatching';
+import { Brief } from '../..';
 
 export interface SliceBriefOptions {
   /**
@@ -16,12 +15,19 @@ export interface SliceBriefOptions {
   end?: number;
 }
 
+/**
+ * Slice a Brief to keep only the desired keypoints and the corresponding descriptors.
+ *
+ * @param brief - Brief to process
+ * @param options - Slice Brief options.
+ * @returns The desired keypoints + descriptors.
+ */
 export function sliceBrief(
   brief: Brief,
   options: SliceBriefOptions = {},
 ): Brief {
   const { start = 0, end = brief.keypoints.length } = options;
-  if (start < 0 || end > brief.keypoints.length - 1) {
+  if (start < 0 || end > brief.keypoints.length) {
     throw new Error('start or end are out of range');
   }
   return {