diff --git a/.npmignore b/.npmignore
index 547281a..ffadfa3 100644
--- a/.npmignore
+++ b/.npmignore
@@ -5,6 +5,8 @@ browser.js
 bundle.js*
 *.tgz
 vectorize-pixelart-bundle.js
+vectorize-pixelart.js
 .travis.yml
+.github
 src
-tsconfig.json
\ No newline at end of file
+tsconfig.json
diff --git a/contour-tracing.js b/contour-tracing.js
deleted file mode 100644
index c3a554a..0000000
--- a/contour-tracing.js
+++ /dev/null
@@ -1,3 +0,0 @@
-// Left for backward compatability, please do not rely on it
-const { ContourTracing } = require('./lib')
-module.exports = ContourTracing
diff --git a/package.json b/package.json
index 2d2d8b5..fe01a13 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "vectorize-pixelart",
-  "version": "0.2.0",
+  "version": "1.0.0",
   "description": "Convert raster pixel art graphics to vector",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
diff --git a/src/contour-tracing.ts b/src/contour-tracing.ts
index f5e6d4e..8977beb 100644
--- a/src/contour-tracing.ts
+++ b/src/contour-tracing.ts
@@ -1,7 +1,7 @@
-import { Coord, Path, Pixel, PNGImageData } from './utils'
+import { Coord, Path, RGBA, PNGImageData } from './utils'
 
 type Direction = Coord
-type ContourFoundCb = (contour: Path, pixel: Pixel) => void
+type ContourFoundCb = (contour: Path, pixel: RGBA) => void
 
 const DIRECTIONS: Direction[] = [
   [1, 0],
@@ -74,8 +74,7 @@ export class ContourTracing {
   }
 
   addContour (contour: Path, y: number, x: number, startDirection: number, endDirection: number): void {
-  // console.log("addContour: ", y, x, startDirection, endDirection);
-
+    // console.log("addContour: ", y, x, startDirection, endDirection);
     if (startDirection === endDirection) { return }
 
     for (let direction = (startDirection + D_MOD - 1) % D_MOD, firstRun = true; firstRun || direction !== endDirection; direction = (direction + 1) % D_MOD, firstRun = false) {
diff --git a/src/utils.ts b/src/utils.ts
index 561a533..e5fb726 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -4,11 +4,11 @@ import type { PNG } from 'pngjs'
 
 const DEFAULT_MULTIPLIER = 1
 
-export type Pixel = [number, number, number, number]
+export type RGBA = [number, number, number, number]
 export type Coord = [number, number]
 export type Path = Coord[]
 
-abstract class Image {
+export abstract class Image {
   protected readonly height: number
   protected readonly width: number
   protected readonly multiplier: number
@@ -22,7 +22,7 @@ abstract class Image {
   abstract header (): string
   abstract footer (): string
   // abstract pixel(y: number, x: number, pixel: Pixel): string | undefined
-  abstract path (contour: Path, pixel: Pixel): string
+  abstract path (contour: Path, pixel: RGBA): string
 }
 
 export class SVG extends Image {
@@ -37,7 +37,7 @@ export class SVG extends Image {
     return '</svg>\n'
   }
 
-  pixel (y: number, x: number, pixel: Pixel): string {
+  pixel (y: number, x: number, pixel: RGBA): string {
     if (pixel[3] < 255) {
       return ''
     }
@@ -49,7 +49,7 @@ width="${1 * this.multiplier}" height="${1 * this.multiplier}" \
 style="fill:rgba(${rgba})" />\n`
   }
 
-  path (contour: Path, pixel: Pixel): string {
+  path (contour: Path, pixel: RGBA): string {
     const m = this.multiplier
     const rgba = pixel.join(', ')
 
@@ -94,7 +94,7 @@ showpage
 `
   }
 
-  path (contour: Path, pixel: Pixel): string {
+  path (contour: Path, pixel: RGBA): string {
     const m = this.multiplier
     const height = this.height
 
@@ -143,8 +143,8 @@ export class PNGImageData {
     return true
   }
 
-  getPixel (y: number, x: number): Pixel {
+  getPixel (y: number, x: number): RGBA {
     const offset = (y * this.width + x) * BYTES_PER_PIXEL
-    return Array.prototype.slice.call(this.data, offset, offset + BYTES_PER_PIXEL) as Pixel
+    return Array.prototype.slice.call(this.data, offset, offset + BYTES_PER_PIXEL) as RGBA
   }
 }
diff --git a/src/vectorize-pixelart.ts b/src/vectorize-pixelart.ts
index d5d8bbb..ef721f5 100755
--- a/src/vectorize-pixelart.ts
+++ b/src/vectorize-pixelart.ts
@@ -2,7 +2,7 @@
 
 import { createReadStream, createWriteStream } from 'fs'
 import { PNG } from 'pngjs'
-import { SVG, EPS, PNGImageData, Path, Pixel } from './utils'
+import { SVG, EPS, PNGImageData, Path, RGBA } from './utils'
 import * as Process from 'process'
 import { ContourTracing } from './contour-tracing'
 
@@ -11,7 +11,6 @@ const OutputFileFormats: { [_: string]: any } = {
   eps: EPS
 }
 
-const targetSize = 2 ** 23
 const inputFileName = Process.argv[2]
 const outputFileName: string = Process.argv[3]
 
@@ -31,16 +30,14 @@ createReadStream(inputFileName)
     // TODO check files exists
     const vectorOut = createWriteStream(outputFileName)
 
-    const pixelMultiplier = Math.sqrt(targetSize / (this.height * this.width))
-
     const image = new PNGImageData(this)
 
-    const vectorFormatter = new VectorFormatterClass(this.height, this.width, pixelMultiplier)
+    const vectorFormatter = new VectorFormatterClass(this.height, this.width)
     vectorOut.write(vectorFormatter.header())
 
     const tracer = new ContourTracing(image)
-    tracer.traceContours((contour: Path, pixel: Pixel) => {
-      vectorOut.write(vectorFormatter.path(contour, pixel))
+    tracer.traceContours((contour: Path, color: RGBA) => {
+      vectorOut.write(vectorFormatter.path(contour, color))
     })
 
     vectorOut.write(vectorFormatter.footer())
diff --git a/test/tracing.test.ts b/test/tracing.test.ts
index 30428a6..216be86 100644
--- a/test/tracing.test.ts
+++ b/test/tracing.test.ts
@@ -1,6 +1,6 @@
 import * as test from 'tape'
 import { ContourTracing } from '../src/contour-tracing'
-import { Coord, Path, PNGImageData } from '../src/utils'
+import { Coord, Path, RGBA, PNGImageData } from '../src/utils'
 
 test('trace contours of sample image', (t) => {
   const imageData = [
@@ -66,7 +66,7 @@ constructor (imageArray: number[], height: number, width: number) {
     return this.image[this.getOffset(y1, x1)] === this.image[this.getOffset(y2, x2)]
   }
 
-  getPixel (y: number, x: number) {
+  getPixel (y: number, x: number): RGBA {
     const gray = 255 * this.image[this.getOffset(y, x)]
     return [gray, gray, gray, 255]
   }
diff --git a/tsconfig.json b/tsconfig.json
index 42ede86..47a7c18 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -8,5 +8,5 @@
     "strict": true
   },
   "include": ["src/**/*"],
-  "exclude": ["node_modules", "test"]
+  "exclude": ["node_modules"]
 }
diff --git a/utils.js b/utils.js
deleted file mode 100644
index 06d29e2..0000000
--- a/utils.js
+++ /dev/null
@@ -1,3 +0,0 @@
-// Left for backward compatability, please do not rely on it
-const { SVG, EPS, PNGImageData } = require('./lib')
-module.exports = { SVG, EPS, PNGImageData }