import javax.imageio.ImageIO;

import javax.swing.*;

import java.awt.*;

import java.awt.image.BufferedImage;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.IOException;

public class testImage

{

/**

* 图片旋转

* @param src 原始图

* @param angel 旋转角度

* @return 结果图字节数据组

*/

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

int src_width = src.getWidth(null);

int src_height = src.getHeight(null);

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();

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 res;

}

public static Rectangle CalcRotatedSize(Rectangle src, int 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));

}

/**

* 对图片中的 黑色或白色进行透明化处理

* @param sourcePath 原始图

* @param targetPath 目标图,为null时在原始图同级目录下生成目标图

* @return 结果图字节数据组

*/

public static byte[] transferAlpha(String sourcePath,String targetPath,int color) {

ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

try {

File iFile = new File(sourcePath);

if(!iFile.exists()) return byteArrayOutputStream.toByteArray();

ImageIcon imageIcon = new ImageIcon(ImageIO.read(iFile));

BufferedImage bufferedImage = new BufferedImage(

imageIcon.getIconWidth(), imageIcon.getIconHeight(),

BufferedImage.TYPE_4BYTE_ABGR);

Graphics2D g2D = (Graphics2D) bufferedImage.getGraphics();

g2D.drawImage(imageIcon.getImage(), 0, 0,imageIcon.getImageObserver());

int alpha = 0;

for (int j1 = bufferedImage.getMinY(); j1 < bufferedImage.getHeight(); j1++) {

for (int j2 = bufferedImage.getMinX(); j2 < bufferedImage.getWidth(); j2++) {

int rgb = bufferedImage.getRGB(j2, j1);

if (checkColor(rgb,16,color)) {

rgb = ((alpha + 1) << 24) | (rgb & 0x00ffffff);

}

bufferedImage.setRGB(j2, j1, rgb);

}

}

g2D.drawImage(bufferedImage, 0, 0, imageIcon.getImageObserver());

File targetFile = null;

if(targetPath == null){

targetFile = new File(sourcePath+"_"+color+".png");

}else{

targetFile = new File(targetPath);

if(!targetFile.exists()){

File dir = new File(targetFile.getParent());

if(!dir.exists()) dir.mkdirs();

}

}

ImageIO.write(bufferedImage, "png", targetFile);

} catch (Exception e) {

e.printStackTrace();

}

return byteArrayOutputStream.toByteArray();

}

/**

* 检查颜色是否为 白色 或者 黑色阈值范围

* @param rgb 颜色值

* @param color 0:白色 1:黑色

* @return 检查结果

*/

private static boolean checkColor(int rgb,int offset,int color){

int R = (rgb & 0xff0000) >> 16;

int G = (rgb & 0xff00) >> 8;

int B = (rgb & 0xff);

if(color == 0){

return ((255 - R) <= offset) && ((255 - G) <= offset) && ((255 - B) <= offset);

}else{

return ((R <= offset) && (G <= offset) && (B <= offset));

}

}

public static void main(String[] args) throws IOException {

Image src = ImageIO.read(new File("C://Users//Mr.Ma//Desktop//20190616132703.png"));

BufferedImage bufferedImage = Rotate(src,90);

ImageIO.write(bufferedImage, "png", new File("C://Users//Mr.Ma//Desktop//3.png"));

//去除影像黑边

transferAlpha("C://Users//Mr.Ma//Desktop//3.png","C://Users//Mr.Ma//Desktop//3.png",1);

System.out.printf("生成完毕");

}

}