image-comparator - npm Package Compare versions

Comparing version 1.2.0 to 1.3.0

index.js

@@ -11,3 +11,3 @@ const {
 module.exports = {
-  compare: async (buffer1, buffer2) => {
+  compare: async (buffer1, buffer2, comparator) => {
     const isInterformatComparison =
@@ -22,4 +22,4 @@ buffer1[0] === MIMES.WEBP && buffer1[0] !== buffer2[0];
       ...(await Promise.all([compareImpl(buffer1), compareImpl(buffer2)])),
-      BYTE_COMPARERS[buffer1[0]],
-      BYTE_COMPARERS[buffer2[0]],
+      comparator || BYTE_COMPARERS[buffer1[0]],
+      comparator || BYTE_COMPARERS[buffer2[0]],
       buffer1[0]
@@ -26,0 +26,0 @@ );

package.json

 {
   "name": "image-comparator",
-  "version": "1.2.0",
+  "version": "1.3.0",
   "description": "Compares images by resizing without dependencies",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

@@ -29,15 +29,94 @@ # image-comparator
 
-const areSame = await comparator.compare(imageBuffer1, imageBuffer2);
+const compare = async () => {
+  const areSame = await comparator.compare(imageBuffer1, imageBuffer2);
 
-if (areSame) {
-  console.log("Images are the same");
-} else {
-  console.log("Images are different");
-}
+  if (areSame) {
+    console.log("Images are the same");
+  } else {
+    console.log("Images are different");
+  }
+};
+
+compare();
 ```
 
-## Supported formats
+### With custom threshold
 
+```js
+const fs = require("node:fs");
+const comparator = require("image-comparator");
+
+const imagePath1 = "path/to/same.png";
+const imagePath2 = "path/to/same.jpg";
+
+const imageBuffer1 = fs.readFileSync(imagePath1);
+const imageBuffer2 = fs.readFileSync(imagePath2);
+
+const compare = async () => {
+  const compareFunction = (byte1, byte2) => false; // Images are always different
+
+  const areSame = await comparator.compare(
+    imageBuffer1,
+    imageBuffer2,
+    compareFunction
+  );
+
+  if (areSame) {
+    throw new Error("Should not happen");
+  } else {
+    console.log("Images are different");
+  }
+};
+
+compare();
+```
+
+```js
+const fs = require("node:fs");
+const comparator = require("image-comparator");
+
+const imagePath1 = "path/to/same.png";
+const imagePath2 = "path/to/same.jpg";
+
+const imageBuffer1 = fs.readFileSync(imagePath1);
+const imageBuffer2 = fs.readFileSync(imagePath2);
+
+const compare = async () => {
+  const compareFunction = (byte1, byte2) => Math.abs(byte1 - byte2) < 128; // If color difference is small enough
+
+  const areSame = await comparator.compare(
+    imageBuffer1,
+    imageBuffer2,
+    compareFunction
+  );
+
+  if (areSame) {
+    console.log("Images are the same");
+  } else {
+    console.log("Images are different");
+  }
+};
+
+compare();
+```
+
+# API
+
+```js
+compare: (
+  buffer1: Buffer,
+  buffer2: Buffer,
+  compareFunction: (byte1, byte2) => boolean
+) => bool;
+```
+
+Compares two images.
+
+Throws if WEBP image is compared with imag of another extension.
+
+## Supported extensions
+
 - png
 - jpg
+- webp
 
@@ -52,2 +131,3 @@ ## Detection algorithm
 
-May produce false positives for comparison of images of different format origins due to inconsistent resulting bitmap size
+- May produce false positives for comparison of images of different format origins due to inconsistent resulting bitmap size (use `compareFunction` to avoid this)
+- Can work with interformat images, but WEBP is not supported for this at the moment

test/index.js

@@ -34,2 +34,26 @@ const assert = require("node:assert");
   });
+
+  it("should perceive different images as same with low threshold", async () => {
+    const expected = true;
+    const comparator = (byte1, byte2) => Math.abs(byte1 - byte2) < 256;
+    const commonPathSegments = [...commonPngImagesPath, "different"];
+    const image1 = readFileSync(join(...commonPathSegments, "image1.png"));
+    const image2 = readFileSync(join(...commonPathSegments, "image2.png"));
+
+    const actual = await compare(image1, image2, comparator);
+
+    assert.strictEqual(actual, expected);
+  });
+
+  it("should perceive same images as different with high threshold", async () => {
+    const expected = false;
+    const comparator = (byte1, byte2) => Math.abs(byte1 - byte2) > 255;
+    const commonPathSegments = [...commonPngImagesPath, "same"];
+    const image1 = readFileSync(join(...commonPathSegments, "image1.png"));
+    const image2 = readFileSync(join(...commonPathSegments, "image2.png"));
+
+    const actual = await compare(image1, image2, comparator);
+
+    assert.strictEqual(actual, expected);
+  });
 });
@@ -61,10 +85,34 @@
   });
+
+  it("should perceive different images as same with low threshold", async () => {
+    const expected = true;
+    const comparator = (byte1, byte2) => Math.abs(byte1 - byte2) < 256;
+    const commonPathSegments = [...commonJpgImagesPath, "different"];
+    const image1 = readFileSync(join(...commonPathSegments, "image1.jpg"));
+    const image2 = readFileSync(join(...commonPathSegments, "image2.jpg"));
+
+    const actual = await compare(image1, image2, comparator);
+
+    assert.strictEqual(actual, expected);
+  });
+
+  it("should perceive same images as different with high threshold", async () => {
+    const expected = false;
+    const comparator = (byte1, byte2) => Math.abs(byte1 - byte2) > 255;
+    const commonPathSegments = [...commonJpgImagesPath, "same"];
+    const image1 = readFileSync(join(...commonPathSegments, "image1.jpg"));
+    const image2 = readFileSync(join(...commonPathSegments, "image2.jpg"));
+
+    const actual = await compare(image1, image2, comparator);
+
+    assert.strictEqual(actual, expected);
+  });
 });
 
 describe("webp", () => {
-  const commonJpgImagesPath = [...commonImagesPath, "webp"];
+  const commonWebpImagesPath = [...commonImagesPath, "webp"];
 
   it("should return false for different webp images", async () => {
     const expected = false;
-    const commonPathSegments = [...commonJpgImagesPath, "different"];
+    const commonPathSegments = [...commonWebpImagesPath, "different"];
     const image1 = readFileSync(join(...commonPathSegments, "image1.webp"));
@@ -80,3 +128,3 @@ const image2 = readFileSync(join(...commonPathSegments, "image2.webp"));
     const expected = true;
-    const commonPathSegments = [...commonJpgImagesPath, "same"];
+    const commonPathSegments = [...commonWebpImagesPath, "same"];
     const image1 = readFileSync(join(...commonPathSegments, "image1.webp"));
@@ -89,2 +137,26 @@ const image2 = readFileSync(join(...commonPathSegments, "image2.webp"));
   });
+
+  it("should perceive different images as same with low threshold", async () => {
+    const expected = true;
+    const comparator = (byte1, byte2) => Math.abs(byte1 - byte2) < 256;
+    const commonPathSegments = [...commonWebpImagesPath, "different"];
+    const image1 = readFileSync(join(...commonPathSegments, "image1.webp"));
+    const image2 = readFileSync(join(...commonPathSegments, "image2.webp"));
+
+    const actual = await compare(image1, image2, comparator);
+
+    assert.strictEqual(actual, expected);
+  });
+
+  it("should perceive same images as different with high threshold", async () => {
+    const expected = false;
+    const comparator = (byte1, byte2) => Math.abs(byte1 - byte2) > 255;
+    const commonPathSegments = [...commonWebpImagesPath, "same"];
+    const image1 = readFileSync(join(...commonPathSegments, "image1.webp"));
+    const image2 = readFileSync(join(...commonPathSegments, "image2.webp"));
+
+    const actual = await compare(image1, image2, comparator);
+
+    assert.strictEqual(actual, expected);
+  });
 });
@@ -137,2 +209,14 @@
   });
+
+  it("should perceive same interformat images as different with high threshold", async () => {
+    const expected = false;
+    const comparator = (byte1, byte2) => Math.abs(byte1 - byte2) > 255;
+    const commonPathSegments = [...commonImagesPath, "mixins"];
+    const image1 = readFileSync(join(...commonPathSegments, "image.jpg"));
+    const image2 = readFileSync(join(...commonPathSegments, "image.png"));
+
+    const actual = await compare(image1, image2, comparator);
+
+    assert.strictEqual(actual, expected);
+  });
 });

No alert changes

Improved metrics

Total package byte prevSize

183033

increased by3.02%

Lines of code

3089

increased by2.08%

Number of lines in readme file

132

increased by153.85%

No dependency changes