image-cropper 是一个很好的 Jquery插件，可以实现图片的选择，旋转，剪切。 可以用做网站头像的处理。

点击"DONE"按钮，会向后端发送 JSON切割数据，后端的 java代码如下：

package net.watermelon.core.util;

import java.io.*;

import java.awt.*;

import java.awt.image.*;

import java.awt.Graphics;

import java.awt.color.ColorSpace;

import javax.imageio.ImageIO;

public class ImageCut {

public static BufferedImage cut(BufferedImage inputImage,int x,int y,int width,int height,boolean fill){

//获取原始图像透明度类型

int type =BufferedImage.TYPE_INT_RGB;// inputImage.getColorModel().getTransparency();

int w = inputImage.getWidth();

int h = inputImage.getHeight();

int endx=x+width;

int endy=y+height;

if(x>w)

throw new ImagingOpException("起点横坐标超出源图像范围");

if(y>h)

throw new ImagingOpException("起点纵坐标超出源图像范围");

BufferedImage img;

//补白

if(fill){

img = new BufferedImage(width, height, type);

//宽度超出限制

if((w-x)

width=w-x;

endx=w;

}

//高度超出限制

if((h-y)

height=h-y;

endy=h;

}

//不补

}else{

//宽度超出限制

if((w-x)

width=w-x;

endx=w;

}

//高度超出限制

if((h-y)

height=h-y;

endy=h;

}

img = new BufferedImage(width, height, type);

}

Graphics2D graphics2d =img.createGraphics();

BufferedImage imageNew = graphics2d.getDeviceConfiguration().createCompatibleImage(width, height,

Transparency.TRANSLUCENT);

graphics2d =imageNew.createGraphics();

graphics2d.drawImage(inputImage, 0, 0, width, height, x, y, endx, endy, null);

graphics2d.dispose();

return imageNew;

}

/**

* 缩放图像

*

* @param srcImageFile       源图像文件地址

* @param result             缩放后的图像地址

* @param scale              缩放比例

* @param flag               缩放选择:true 放大; false 缩小;

*/

public static void scale(String srcImageFile, String result, int scale,

boolean flag) {

try {

BufferedImage src = ImageIO.read(new File(srcImageFile)); // 读入文件

int width = src.getWidth(); // 得到源图宽

int height = src.getHeight(); // 得到源图长

if (flag) {

// 放大

width = width * scale;

height = height * scale;

} else {

// 缩小

width = width / scale;

height = height / scale;

}

Image image = src.getScaledInstance(width, height,Image.SCALE_DEFAULT);

BufferedImage tag = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);

Graphics g = tag.getGraphics();

g.drawImage(image, 0, 0, null); // 绘制缩小后的图

g.dispose();

ImageIO.write(tag, "JPEG", new File(result));// 输出到文件流

} catch (IOException e) {

e.printStackTrace();

}

}

/**

* 重新生成按指定宽度和高度的图像

* @param srcImageFile       源图像文件地址

* @param result             新的图像地址

* @param _width             设置新的图像宽度

* @param _height            设置新的图像高度

*/

public static void scale(String srcImageFile, String result, int _width,int _height) {

scale(srcImageFile,result,_width,_height,0,0);

}

public static void scale(String srcImageFile, String result, int _width,int _height,int x,int y) {

try {

BufferedImage src = ImageIO.read(new File(srcImageFile)); // 读入文件

int width = src.getWidth(); // 得到源图宽

int height = src.getHeight(); // 得到源图长

if (width > _width) {

width = _width;

}

if (height > _height) {

height = _height;

}

Image image = src.getScaledInstance(width, height,Image.SCALE_DEFAULT);

BufferedImage tag = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);

Graphics g = tag.getGraphics();

g.drawImage(image, x, y, null); // 绘制缩小后的图

g.dispose();

ImageIO.write(tag, "JPEG", new File(result));// 输出到文件流

} catch (IOException e) {

e.printStackTrace();

}

}

/**

* 图像类型转换 GIF->JPG GIF->PNG PNG->JPG PNG->GIF(X)

*/

public static void convert(String source, String result) {

try {

File f = new File(source);

f.canRead();

f.canWrite();

BufferedImage src = ImageIO.read(f);

ImageIO.write(src, "JPG", new File(result));

} catch (Exception e) {

e.printStackTrace();

}

}

/**

* 彩色转为黑白

*

* @param source

* @param result

*/

public static void gray(String source, String result) {

try {

BufferedImage src = ImageIO.read(new File(source));

ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);

ColorConvertOp op = new ColorConvertOp(cs, null);

src = op.filter(src, null);

ImageIO.write(src, "JPEG", new File(result));

} catch (IOException e) {

e.printStackTrace();

}

}

/**

* 选择任意角度

* @param bufferedimage

* @param degree

* @return

*/

public static Rectangle CalcRotatedSize(Rectangle src, int angel) {

// if angel is greater than 90 degree, we need to do some conversion

angel = Math.abs(angel);

if (angel >= 90) {

if(angel / 90 % 2 == 1){

int temp = src.height;

src.height = src.width;

src.width = temp;

}

angel = angel % 90;

}

double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;

double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;

double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;

double angel_dalta_width = Math.atan((double) src.height / src.width);

double angel_dalta_height = Math.atan((double) src.width / src.height);

int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha

- angel_dalta_width));

int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha

- angel_dalta_height));

int des_width = src.width + len_dalta_width * 2;

int des_height = src.height + len_dalta_height * 2;

return new java.awt.Rectangle(new Dimension(des_width, des_height));

}

public static BufferedImage Rotate(Image src, int angel) {

int src_width = src.getWidth(null);

int src_height = src.getHeight(null);

// calculate the new image size

Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(

src_width, src_height)), angel);

BufferedImage res = null;

res = new BufferedImage(rect_des.width, rect_des.height,

BufferedImage.TYPE_INT_RGB);

Graphics2D g2 = res.createGraphics();

BufferedImage imageNew = g2.getDeviceConfiguration().createCompatibleImage(rect_des.width, rect_des.height,

Transparency.TRANSLUCENT);

g2 = imageNew.createGraphics();

// transform

g2.translate((rect_des.width - src_width) / 2,

(rect_des.height - src_height) / 2);

g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);

g2.drawImage(src, null, null);

return imageNew;

}

public static void main(String[] argv) throws Exception{

String srcImageFile="c:\\model2.jpg";

BufferedImage img =ImageIO.read(new File(srcImageFile));

BufferedImage nimg = ImageCut.Rotate(img,0);

img = ImageCut.cut(nimg,89,43,101,101,true);

ImageIO.write(img, "png", new File("c:\\model21.png"));

}

}

可以简单地完成头像的切割和保存。