(#68) Moved scaling of Region location into separate function

Author: s1hofmann

lib/provider/opencv/scale-location.function.spec.ts

@@ -0,0 +1,30 @@
+import { Region } from "../../region.class";
+import { scaleLocation } from "./scale-location.function";
+
+describe("scaleLocation", () => {
+  it("should scale location of a Region for valid scale factors", () => {
+    // GIVEN
+    const scaleFactor = 0.5;
+    const inputRegion = new Region(100, 100, 10, 10);
+    const expectedRegion = new Region(200, 200, 10, 10);
+
+    // WHEN
+    const result = scaleLocation(inputRegion, scaleFactor);
+
+    // THEN
+    expect(result).toEqual(expectedRegion);
+  });
+
+  it("should not scale location of a Region for invalid scale factors", () => {
+    // GIVEN
+    const scaleFactor = 0.0;
+    const inputRegion = new Region(100, 100, 10, 10);
+    const expectedRegion = new Region(100, 100, 10, 10);
+
+    // WHEN
+    const result = scaleLocation(inputRegion, scaleFactor);
+
+    // THEN
+    expect(result).toEqual(expectedRegion);
+  });
+});

lib/provider/opencv/scale-location.function.ts

@@ -0,0 +1,15 @@
+import { Region } from "../../region.class";
+import { lowerBound } from "./bound-value.function";
+
+export const scaleLocation = (
+  result: Region,
+  scaleFactor: number,
+): Region => {
+  const boundScaleFactor = lowerBound(scaleFactor, 0.0, 1.0);
+  return new Region(
+    result.left / boundScaleFactor,
+    result.top / boundScaleFactor,
+    result.width,
+    result.height,
+  );
+};