fix: background and noise

Author: piercus

lib/backend/opencv-backend.js

@@ -154,13 +154,16 @@ class OpenCVBackend {
 		}
 
 		if (channels === 4) {
+			
 			const channels = foreground.splitChannels();
 			const a = channels[3].cvtColor(this._cv.COLOR_GRAY2BGR).convertTo(this._cv.CV_32FC3, 1 / 255);
+			const white = new this._cv.Mat(height, width, this._cv.CV_8UC3).convertTo(this._cv.CV_32FC3, 1 / 255, 1);
+			const inverseA = white.sub(a);
 			const b = foreground.cvtColor(this._cv.COLOR_BGRA2BGR).convertTo(this._cv.CV_32FC3);
 			const foreW = b.hMul(a);
-			const inverseA = new this._cv.Mat(height, width, this._cv.CV_32FC3, new this._cv.Vec(1, 1, 1)).sub(a);
-			const backW = foreground.cvtColor(this._cv.COLOR_BGRA2BGR).convertTo(this._cv.CV_32FC3).hMul(inverseA);
-			return foreW.add(backW).convertTo(this._cv.CV_8UC3);
+			const backW = background.convertTo(this._cv.CV_8UC3).cvtColor(this._cv.COLOR_BGRA2BGR).convertTo(this._cv.CV_32FC3).hMul(inverseA);
+			const res = foreW.add(backW).convertTo(this._cv.CV_8UC3);
+			return res
 		} else {
 			throw(new Error(`invalid channels (${channels})`))
 		}

lib/generators/gaussian-noise.js

@@ -49,7 +49,7 @@ class GaussianNoiseGenerator extends AbstractNoise {
 		return h.round(h.number({
 			type: 'normal',
 			mean: this.mean,
-			sigma: this.sigma
+			std: this.sigma
 		}));
 	}
 }

test/generators/gaussian-noise.js

@@ -3,16 +3,17 @@ const test = require('ava');
 const GaussianNoise = require('../../lib/generators/gaussian-noise');
 const macroGenerator = require('../macros/generator');
 
-const width = 55;
-const height = 32;
+const width = 59;
+const height = 47;
 const channels = 3;
-const mean = 2;
+const mean = 128;
+const sigma = 50;
 
 test('perspective-transform sigma 4 and transparent', macroGenerator, GaussianNoise, {
 	debugOutput: path.join(__dirname, '../..', 'tmp/gaussian-noise.png'),
 	expectImg: (t, img) => {
-		t.is(img.cols, 55);
-		t.is(img.rows, 32);
+		t.is(img.cols, width);
+		t.is(img.rows, height);
 		const sum = img.getDataAsArray()
 			.reduce((a, b) => a.concat(b))
 			.reduce((a, b) => a.concat(b))
@@ -27,6 +28,7 @@ test('perspective-transform sigma 4 and transparent', macroGenerator, GaussianNo
 	channels,
 	options: {
 		mean,
-		scale: 0.2
+		scale: 1,
+		sigma
 	}
 });

test/macros/generator.js

@@ -18,8 +18,7 @@ module.exports = function (t, Cstr, {
 			if (!debugOutput) {
 				return Promise.resolve();
 			}
-
-			backend.writeImage(debugOutput, res);
+			backend.writeImage(debugOutput, res.resize(200,200));
 		})
 		.then(() => {
 			if (!expectImg) {