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){
width=w-x;
endx=w;
}
//高度超出限制
if((h-y)<height){
height=h-y;
endy=h;
}
//不补
}else{
//宽度超出限制
if((w-x)<width){
width=w-x;
endx=w;
}
//高度超出限制
if((h-y)<height){
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。