https://github.com/li-na/optipng.js
The native javascript png optimizer. Live demo:
https://github.com/li-na/optipng.js
emscripten image-processing javascript nodejs optimization optimizer optipng png
Last synced: 11 months ago
JSON representation
The native javascript png optimizer. Live demo:
- Host: GitHub
- URL: https://github.com/li-na/optipng.js
- Owner: LI-NA
- License: mit
- Created: 2018-05-09T19:21:37.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2018-05-14T00:18:36.000Z (about 8 years ago)
- Last Synced: 2025-07-14T15:34:04.409Z (11 months ago)
- Topics: emscripten, image-processing, javascript, nodejs, optimization, optimizer, optipng, png
- Language: JavaScript
- Homepage: https://li-na.github.io/optipng.js/
- Size: 2.89 MB
- Stars: 11
- Watchers: 2
- Forks: 3
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Optipng.js
Optipng.js is the port of [optipng](http://optipng.sourceforge.net/) in javascript using [emscripten](https://github.com/kripken/emscripten). You can optimize png image file without losing any information in the morden browser using Optipng.js.
Tip: Optipng version is 0.7.7.
## API
### `optipng(file, options, printFunction)`
#### `file`
Please use binary file like readFile on node or Uint8Array (converted from base64) on javascript.
```javascript
// Node.js
var input = fs.readFileSync("input.png");
var output = optipng(input, ["-o2"]);
```
```javascript
// Browser
function dataURLtoUint8(dataurl) {
var arr = dataurl.split(','),
mime = arr[0].match(/:(.*?);/)[1],
bstr = atob(arr[1]),
n = bstr.length,
u8arr = new Uint8Array(n);
while (n--) {
u8arr[n] = bstr.charCodeAt(n);
}
return u8arr;
}
function readFile (file, callback) {
var fileReader = new FileReader();
fileReader.onload = function() {
var ary = dataURLtoUint8(this.target.result);
callback(ary);
};
fileReader.readAsDataURL(file);
}
var input, output;
readFile(your_file_on_here, function(ary) {
input = ary;
output = optipng(input, ["-o2"]);
// do something with output
});
```
#### `options`
Options can be array or object.
```javascript
var options = ["-o2", "-i0", "-strip", "all"];
var options = {o2: true, i0: true, strip: "all"};
// Both options is same options. If use boolean in value, value will be ignored and only key will be inserted as options.
```
#### `printFunction`
This callback function is optional. It will be called if optipng will print something on stdout or stderr.
```javascript
optipng(input, ["-o2"], function(str) {
console.log(str);
});
```
#### `return`
```javascript
output = {
data: [output file],
stdout: [output string],
stderr: [error string]
};
```
## Full Example
### Node.js
```
$ npm i -S optipng-js
```
```javascript
var optipng = require("optipng-js");
var fs = require("fs");
var input = fs.readFileSync("input.png");
var output = optipng(input, ["-o2"]);
// var output = optipng(input, {"o2": true});
/*
output = {
data: output file,
stdout: output string,
stderr: error string
}
*/
console.log(output.stdout);
console.log(output.stderr);
fs.writeFileSync("output.png", output.data);
```
### Browser
Please check Demo with Web worker. [https://li-na.github.io/optipng.js/](https://li-na.github.io/optipng.js/)
## Build
Actually, I don't know what it is but I made build shell script and it seems working. Please let me know if you have ANY better way to build this project.
You have to setup emscripten sdk on [here](http://kripken.github.io/emscripten-site/docs/getting_started/downloads.html) first.
Then, download or clone this git on your linux computer. (Windows does not supported at this moment)
```
$ git clone https://github.com/LI-NA/optipng.js
```
Finally, just run `./build.sh`. It will configure optipng and compile with emcc.
## License
[MIT License](LICENSE)
Optipng source code is under [zlib license](deps/optipng/LICENSE.txt)