![images logo](https://raw.github.com/zhangyuanwei/node-images/master/demo/logo.png)
===========

Cross-platform image decoder(png/jpeg/gif) and encoder(png/jpeg) for Node.js  
Node.js轻量级跨平台图像编解码库

``` javascript
var images = require("images");

images("input.jpg")                     //Load image from file 
                                        //加载图像文件
    .size(400)                          //Geometric scaling the image to 400 pixels width
                                        //等比缩放图像到400像素宽
    .draw(images("logo.png"), 10, 10)   //Drawn logo at coordinates (10,10)
                                        //在(10,10)处绘制Logo
    .save("output.jpg", {               //Save the image to a file, with the quality of 50
        quality : 50                    //保存图片到文件,图片质量为50
    });
```

## Support 支持情况

if node >= 10.x, please install images@latest

| Platform | Architecture | Node Version |
|:------|:-------------|:------------|
| Windows | x64 |8, 9, 10, 11, 12|
| OSX | X64 | 8, 9, 10, 11, 12|
| Linux* | x64 |8, 9, 10, 11, 12| 

- The 32-bit system is not supported for the time being.


if  node <= 9.x, please install images@3.1.1

| Platform | Architecture | Node Version |
|:------|:-------------|:------------|
| Windows | x86 & x64 | 0.9.11, 0.10, 0.12, 1, 2, 3, 4, 5, 6, 8, 10|
| OSX | X64| 0.9.11, 0.10, 0.12, 1, 2, 3, 4, 5, 6, 8, 9, 10|
| Linux* | x86 & x64 | 0.9.11, 0.10, 0.12, 1, 2, 3, 4, 5, 6, 8, 10| 

## Features 功能特性

* Lightweight: no need to install any image processing library.
* 轻量级：无需安装任何图像处理库。
* Cross-platform: Released a compiled .node file on windows, just download and start.
* 跨平台：Windows下发布了编译好的.node文件,下载就能用。
* Easy-to-use: Provide jQuery-like chaining API. Simple and reliable!
* 方便用：jQuery风格的API，简单可依赖。

## Installation 安装
	$ npm install images

## API 接口

node-images provide jQuery-like Chaining API,You can start the chain like this:  
node-images 提供了类似jQuery的链式调用API,您可以这样开始:

```javascript
/* Load and decode image from file */
/* 从指定文件加载并解码图像 */
images(file)

/* Create a new transparent image */
/* 创建一个指定宽高的透明图像 */
images(width, height)

/* Load and decode image from a buffer */
/* 从Buffer数据中解码图像 */
images(buffer[, start[, end]])

/* Copy from another image */
/* 从另一个图像中复制区域来创建图像 */
images(image[, x, y, width, height])
```

### images(file)
Load and decode image from file  
从指定文件加载并解码图像

### images(width, height)
Create a new transparent image  
创建一个指定宽高的透明图像

### images(buffer[, start[, end]])
Load and decode image from a buffer  
从Buffer数据中解码图像

### images(image[, x, y, width, height])
Copy from another image  
从另一个图像中复制区域来创建图像

### .fill(red, green, blue[, alpha])
eg:`images(200, 100).fill(0xff, 0x00, 0x00, 0.5)`
Fill image with color  
以指定颜色填充图像

### .draw(image, x, y)
Draw *image* on the current image position( *x* , *y* )  
在当前图像( *x* , *y* )上绘制 *image* 图像

### .encode(type[, config])
eg:`images("input.png").encode("jpg", {operation:50})`
Encode image to buffer, *config* is image setting.  
以指定格式编码当前图像到Buffer，config为图片设置，目前支持设置JPG图像质量  
Return buffer  
返回填充好的Buffer  
**Note:The operation will cut off the chain**  
**注意:该操作将会切断调用链**  
See:.save(file[, type[, config]])
参考:.save(file[, type[, config]])

### .save(file[, type[, config]])
eg:`images("input.png").encode("output.jpg", {operation:50})`
Encoding and save the current image to a *file*, if the *type* is not specified, *type* well be automatically determined according to the *file*, *config* is image setting. eg: `{ operation:50 }`  
编码并保存当前图像到 *file* ,如果type未指定,则根据 *file* 自动判断文件类型，config为图片设置，目前支持设置JPG图像质量

### .size([width[, height]])
Get size of the image or set the size of the image,if the height is not specified, then scaling based on the current width and height  
获取或者设置图像宽高，如果height未指定，则根据当前宽高等比缩放

### .resize(width[, height])
Set the size of the image,if the height is not specified, then scaling based on the current width and height  
设置图像宽高，如果height未指定，则根据当前宽高等比缩放, 默认采用 bicubic 算法。

### .width([width])
Get width for the image or set width of the image  
获取或设置图像宽度

### .height([height])
Get height for the image or set height of the image  
获取或设置图像高度

### images.setLimit(width, height)
Set the limit size of each image  
设置库处理图片的大小限制,设置后对所有新的操作生效(如果超限则抛出异常)

### images.setGCThreshold(value)
Set the garbage collection threshold  
设置图像处理库自动gc的阈值(当*新增*内存使用超过该阈值时，执行垃圾回收)

### images.getUsedMemory()
Get used memory (in bytes)  
得到图像处理库占用的内存大小(单位为字节)

### images.gc()
Forced garbage collection  
强制调用V8的垃圾回收机制