From 7cc3d7afd9b70851324dd77ead2e9a001629d6a9 Mon Sep 17 00:00:00 2001
From: Oleksii Trekhleb <trehleb@gmail.com>
Date: Wed, 21 Apr 2021 07:26:50 +0200
Subject: [PATCH 1/5] Test that two images are identical for the Seam Carving
algorithm.
---
.husky/pre-commit | 1 +
.../__tests__/resizeImageWidth.test.js | 40 ++++++++++++++++++-
2 files changed, 39 insertions(+), 2 deletions(-)
diff --git a/.husky/pre-commit b/.husky/pre-commit
index bec1c08a1a..a29a4166ea 100755
--- a/.husky/pre-commit
+++ b/.husky/pre-commit
@@ -1,5 +1,6 @@
#!/bin/sh
. "$(dirname "$0")/_/husky.sh"
+# @TODO: Implement the pre-commit checks.
# npm run lint
# npm run test
diff --git a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
index b6400a3522..bd9340fc71 100644
--- a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
+++ b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
@@ -4,6 +4,40 @@ import resizeImageWidth from '../resizeImageWidth';
const testImageBeforePath = './src/algorithms/image-processing/seam-carving/__tests__/test-image-before.jpg';
const testImageAfterPath = './src/algorithms/image-processing/seam-carving/__tests__/test-image-after.jpg';
+/**
+ * Compares two images and finds the number of different pixels.
+ *
+ * @param {ImageData} imgA - ImageData for the first image.
+ * @param {ImageData} imgB - ImageData for the second image.
+ * @param {number} threshold - Color difference threshold [0..255]. Smaller - stricter.
+ * @returns {number} - Number of different pixels.
+ */
+function pixelsDiff(imgA, imgB, threshold = 0) {
+ if (imgA.width !== imgB.width || imgA.height !== imgB.height) {
+ throw new Error('Images must have the same size');
+ }
+
+ let differentPixels = 0;
+ const numColorParams = 4; // RGBA
+
+ for (let pixelIndex = 0; pixelIndex < imgA.data.length; pixelIndex += numColorParams) {
+ // Get pixel's color for each image.
+ const [aR, aG, aB] = imgA.data.subarray(pixelIndex, pixelIndex + numColorParams);
+ const [bR, bG, bB] = imgB.data.subarray(pixelIndex, pixelIndex + numColorParams);
+
+ // Get average pixel's color for each image (make them greyscale).
+ const aAvgColor = Math.floor((aR + aG + aB) / 3);
+ const bAvgColor = Math.floor((bR + bG + bB) / 3);
+
+ // Compare pixel colors.
+ if (Math.abs(aAvgColor - bAvgColor) > threshold) {
+ differentPixels += 1;
+ }
+ }
+
+ return differentPixels;
+}
+
describe('resizeImageWidth', () => {
it('should perform content-aware image width reduction', () => {
// @see: https://jestjs.io/docs/asynchronous
@@ -21,6 +55,7 @@ describe('resizeImageWidth', () => {
const canvasAfter = createCanvas(imgAfter.width, imgAfter.height);
const ctxAfter = canvasAfter.getContext('2d');
ctxAfter.drawImage(imgAfter, 0, 0, imgAfter.width, imgAfter.height);
+ const imgDataAfter = ctxAfter.getImageData(0, 0, imgAfter.width, imgAfter.height);
const toWidth = Math.floor(imgBefore.width / 2);
@@ -44,8 +79,9 @@ describe('resizeImageWidth', () => {
expect(imgDataTest.width).toBe(imgAfter.width);
expect(imgDataTest.height).toBe(imgAfter.height);
- // @TODO: Check that images are identical.
- // expect(canvasTest.toDataURL()).toEqual(canvasAfter.toDataURL());
+ const colorThreshold = 10;
+ const differentPixels = pixelsDiff(imgDataTest, imgDataAfter, colorThreshold);
+ expect(differentPixels).toBe(0);
});
});
});
From d4285412a17bf4071e48830761a01d97761d2d81 Mon Sep 17 00:00:00 2001
From: Oleksii Trekhleb <trehleb@gmail.com>
Date: Wed, 21 Apr 2021 07:31:07 +0200
Subject: [PATCH 2/5] Tune the Seam Carving tests.
---
.../seam-carving/__tests__/resizeImageWidth.test.js | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
index bd9340fc71..7c44aafb03 100644
--- a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
+++ b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
@@ -79,7 +79,7 @@ describe('resizeImageWidth', () => {
expect(imgDataTest.width).toBe(imgAfter.width);
expect(imgDataTest.height).toBe(imgAfter.height);
- const colorThreshold = 10;
+ const colorThreshold = 50;
const differentPixels = pixelsDiff(imgDataTest, imgDataAfter, colorThreshold);
expect(differentPixels).toBe(0);
});
From c89241a5b5f56e5f5dbecfc03ae2643e0c9517e9 Mon Sep 17 00:00:00 2001
From: Oleksii Trekhleb <trehleb@gmail.com>
Date: Wed, 21 Apr 2021 07:33:12 +0200
Subject: [PATCH 3/5] Tune the Seam Carving tests.
---
.../seam-carving/__tests__/resizeImageWidth.test.js | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
index 7c44aafb03..9e52d3c515 100644
--- a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
+++ b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
@@ -79,7 +79,8 @@ describe('resizeImageWidth', () => {
expect(imgDataTest.width).toBe(imgAfter.width);
expect(imgDataTest.height).toBe(imgAfter.height);
- const colorThreshold = 50;
+ const pixelsTreshold = 50;
+ const colorThreshold = 100;
const differentPixels = pixelsDiff(imgDataTest, imgDataAfter, colorThreshold);
expect(differentPixels).toBe(0);
});
From 0adad2b7ff24ee43b60d23829f8b7da35ac45f75 Mon Sep 17 00:00:00 2001
From: Oleksii Trekhleb <trehleb@gmail.com>
Date: Wed, 21 Apr 2021 07:36:50 +0200
Subject: [PATCH 4/5] Tune the Seam Carving tests.
---
.../seam-carving/__tests__/resizeImageWidth.test.js | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
index 9e52d3c515..8f91391caa 100644
--- a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
+++ b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
@@ -79,10 +79,13 @@ describe('resizeImageWidth', () => {
expect(imgDataTest.width).toBe(imgAfter.width);
expect(imgDataTest.height).toBe(imgAfter.height);
- const pixelsTreshold = 50;
- const colorThreshold = 100;
+ const colorThreshold = 50;
const differentPixels = pixelsDiff(imgDataTest, imgDataAfter, colorThreshold);
- expect(differentPixels).toBe(0);
+
+ // Allow 10% of pixels to be different
+ const pixelsThreshold = Math.floor(imgAfter.width * imgAfter.height);
+
+ expect(differentPixels).toBeLessThanOrEqual(pixelsThreshold);
});
});
});
From 4b39862bbacddd2bc0505ff57ee9c0c000031e2e Mon Sep 17 00:00:00 2001
From: Oleksii Trekhleb <trehleb@gmail.com>
Date: Wed, 21 Apr 2021 07:37:43 +0200
Subject: [PATCH 5/5] Tune the Seam Carving tests.
---
.../seam-carving/__tests__/resizeImageWidth.test.js | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
index 8f91391caa..9afed97123 100644
--- a/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
+++ b/src/algorithms/image-processing/seam-carving/__tests__/resizeImageWidth.test.js
@@ -83,7 +83,7 @@ describe('resizeImageWidth', () => {
const differentPixels = pixelsDiff(imgDataTest, imgDataAfter, colorThreshold);
// Allow 10% of pixels to be different
- const pixelsThreshold = Math.floor(imgAfter.width * imgAfter.height);
+ const pixelsThreshold = Math.floor((imgAfter.width * imgAfter.height) / 10);
expect(differentPixels).toBeLessThanOrEqual(pixelsThreshold);
});