1.改變圖片像素

private void setAlpha(String os) {

/**

* 增加測試項

* 讀取圖片，繪制成半透明,修改像素

*/

try {

ImageIcon imageIcon = new ImageIcon(os);

BufferedImage bufferedImage = new BufferedImage(imageIcon.getIconWidth(),imageIcon.getIconHeight()

, BufferedImage.TYPE_USHORT_565_RGB);

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

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

imageIcon.getImageObserver());

//循環每一個像素點，改變像素點的Alpha值

int alpha = 100;

System.out.println(System.currentTimeMillis());

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

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

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

int[] rgb = new int[3];

rgb[0] = (pixel & 0xff0000) >> 16;

rgb[1] = (pixel & 0xff00) >> 8;

rgb[2] = (pixel & 0xff);

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

bufferedImage.setRGB(j2, j1, pixel);

}

}

System.out.println(System.currentTimeMillis());

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

//生成圖片為PNG

ImageIO.write(bufferedImage, "jpg", new File("C:\\Desktop\\1.jpg"));

}

catch (Exception e) {

e.printStackTrace();

}

}

2.改變圖片寬高

/**

* 按指定高度 等比例縮放圖片

*

* @param imageFile

* @param newPath

* @param newWidth 新圖的寬度

* @throws IOException

*/

public static void zoomImageScale(File imageFile, String newPath, int newWidth) throws IOException {

System.out.println("------------------------------------------------------------------");

if(!imageFile.canRead())

return;

BufferedImage bufferedImage = ImageIO.read(imageFile);

if (null == bufferedImage)

return;

int originalWidth = bufferedImage.getWidth();

int originalHeight = bufferedImage.getHeight();

double scale = (double)originalWidth / (double)newWidth; // 縮放的比例

int newHeight = (int)(originalHeight / scale);

zoomImageUtils(imageFile, newPath, bufferedImage, newWidth, newHeight);

}

private static void zoomImageUtils(File imageFile, String newPath, BufferedImage bufferedImage, int width, int height)

throws IOException{

String suffix = StringUtils.substringAfterLast(imageFile.getName(), ".");

// 處理 png 背景變黑的問題

if(suffix != null && (suffix.trim().toLowerCase().endsWith("png") || suffix.trim().toLowerCase().endsWith("gif"))){

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

Graphics2D g2d = to.createGraphics();

to = g2d.getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);

g2d.dispose();

g2d = to.createGraphics();

System.out.println(width+"---"+height+"------------------------------------------------------------------"+Image.SCALE_AREA_AVERAGING);

Image from = bufferedImage.getScaledInstance(width, height, Image.SCALE_AREA_AVERAGING);

g2d.drawImage(from, 0, 0, null);

g2d.dispose();

ImageIO.write(to, suffix, new File(newPath));

}else{

System.out.println("------------------------------------------------------------------");

// 高質量壓縮，其實對清晰度而言沒有太多的幫助

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

tag.getGraphics().drawImage(bufferedImage, 0, 0, width, height, null);

FileOutputStream out = new FileOutputStream(newPath); // 將圖片寫入 newPath

JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

JPEGEncodeParam jep = JPEGCodec.getDefaultJPEGEncodeParam(tag);

jep.setQuality(1f, true); //壓縮質量, 1 是最高值

encoder.encode(tag, jep);

out.close();

BufferedImage newImage = new BufferedImage(width, height, bufferedImage.getType());

Graphics g = newImage.getGraphics();

g.drawImage(bufferedImage, 0, 0, width, height, null);

g.dispose();

ImageIO.write(newImage, suffix, new File(newPath));

}

}

3.將圖片文件轉化為字節數組字符串,并對其進行Base64編碼處理

import sun.misc.BASE64Decoder;

import sun.misc.BASE64Encoder;

import java.io.*;

/**

* @author hhr

* @create 2017-09-08

**/

public class Base64Test {

public static void main(String[] args) {

String strImg = GetImageStr();

System.out.println(strImg);

GenerateImage(strImg);

}

//圖片轉化成base64字符串

public static String GetImageStr() {//將圖片文件轉化為字節數組字符串，并對其進行Base64編碼處理

String imgFile = "C:\\Users\\Administrator\\Desktop\\1.png";//待處理的圖片

InputStream in = null;

byte[] data = null;

//讀取圖片字節數組

try {

in = new FileInputStream(imgFile);

data = new byte[in.available()];

in.read(data);

in.close();

} catch (IOException e) {

e.printStackTrace();

}

//對字節數組Base64編碼

BASE64Encoder encoder = new BASE64Encoder();

return encoder.encode(data);//返回Base64編碼過的字節數組字符串

}

//base64字符串轉化成圖片

public static boolean GenerateImage(String imgStr) { //對字節數組字符串進行Base64解碼并生成圖片

if (imgStr == null) //圖像數據為空

return false;

BASE64Decoder decoder = new BASE64Decoder();

try {

//Base64解碼

byte[] b = decoder.decodeBuffer(imgStr);

for (int i = 0; i < b.length; ++i) {

if (b[i] < 0) {//調整異常數據

b[i] += 256;

}

}

//生成jpeg圖片

String imgFilePath = "C://222.jpg";//新生成的圖片

OutputStream out = new FileOutputStream(imgFilePath);

out.write(b);

out.flush();

out.close();

return true;

} catch (Exception e) {

return false;

}

}

總結

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