JAVA實現圖片等比縮放,圖片擷取功能--封裝類
阿新 • • 發佈：2018-12-31
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.WritableRaster;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import javax.imageio.ImageIO;
import com.gzdec.common.log.LoggerUtil;
/**
* 圖片工具類，完成圖片的擷取
*/
public class ImageHelper {
/**
* 實現影象的等比縮放
* @param source
* @param targetW
* @param targetH
* @return
*/
private static BufferedImage resize(BufferedImage source, int targetW,
int targetH) {
// targetW，targetH分別表示目標長和寬
int type = source.getType();
BufferedImage target = null;
double sx = (double) targetW / source.getWidth();
double sy = (double) targetH / source.getHeight();
// 這裡想實現在targetW，targetH範圍內實現等比縮放。如果不需要等比縮放
// 則將下面的if else語句註釋即可
if (sx < sy) {
sx = sy;
targetW = (int) (sx * source.getWidth());
} else {
sy = sx;
targetH = (int) (sy * source.getHeight());
}
if (type == BufferedImage.TYPE_CUSTOM) { // handmade
ColorModel cm = source.getColorModel();
WritableRaster raster = cm.createCompatibleWritableRaster(targetW,
targetH);
boolean alphaPremultiplied = cm.isAlphaPremultiplied();
target = new BufferedImage(cm, raster, alphaPremultiplied, null);
} else
target = new BufferedImage(targetW, targetH, type);
Graphics2D g = target.createGraphics();
// smoother than exlax:
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g.drawRenderedImage(source, AffineTransform.getScaleInstance(sx, sy));
g.dispose();
return target;
}
/**
* 實現影象的等比縮放和縮放後的擷取, 處理成功返回true, 否則返回false
* @param inFilePath 要擷取檔案的路徑
* @param outFilePath 擷取後輸出的路徑
* @param width 要擷取寬度
* @param hight 要擷取的高度
* @throws Exception
*/
public static boolean compress(String inFilePath, String outFilePath,
int width, int hight) {
boolean ret = false;
File file = new File(inFilePath);
File saveFile = new File(outFilePath);
InputStream in = null;
try {
in = new FileInputStream(file);
ret = compress(in, saveFile, width, hight);
} catch (FileNotFoundException e) {
e.printStackTrace();
ret = false;
} finally{
if(null != in){
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return ret;
}
/**
* 實現影象的等比縮放和縮放後的擷取, 處理成功返回true, 否則返回false
* @param inFilePath 要擷取檔案的路徑
* @param outFilePath 擷取後輸出的路徑
* @param width 要擷取寬度
* @param hight 要擷取的高度
* @throws Exception
*/
public static boolean compress(InputStream in, File saveFile,
int width, int hight) {
// boolean ret = false;
BufferedImage srcImage = null;
try {
srcImage = ImageIO.read(in);
} catch (IOException e) {
e.printStackTrace();
return false;
}
if (width > 0 || hight > 0) {
// 原圖的大小
int sw = srcImage.getWidth();
int sh = srcImage.getHeight();
// 如果原影象的大小小於要縮放的影象大小，直接將要縮放的影象複製過去
if (sw > width && sh > hight) {
srcImage = resize(srcImage, width, hight);
} else {
String fileName = saveFile.getName();
String formatName = fileName.substring(fileName
.lastIndexOf('.') + 1);
try {
ImageIO.write(srcImage, formatName, saveFile);
} catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
}
// 縮放後的影象的寬和高
int w = srcImage.getWidth();
int h = srcImage.getHeight();
// 如果縮放後的影象和要求的影象寬度一樣，就對縮放的影象的高度進行擷取
if (w == width) {
// 計算X軸座標
int x = 0;
int y = h / 2 - hight / 2;
try {
saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile);
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
// 否則如果是縮放後的影象的高度和要求的影象高度一樣，就對縮放後的影象的寬度進行擷取
else if (h == hight) {
// 計算X軸座標
int x = w / 2 - width / 2;
int y = 0;
try {
saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile);
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
return true;
}
/**
* 實現影象的等比縮放和縮放後的擷取, 處理成功返回true, 否則返回false
* @param in 圖片輸入流
* @param saveFile 壓縮後的圖片輸出流
* @param proportion 壓縮比
* @throws Exception
* author: cxg 2009-5-24 下午12:05:05
*/
public static boolean compress(InputStream in, File saveFile, int proportion) {
if(null == in
||null == saveFile
||proportion < 1){// 檢查引數有效性
LoggerUtil.error(ImageHelper.class, "--invalid parameter, do nothing!");
return false;
}
BufferedImage srcImage = null;
try {
srcImage = ImageIO.read(in);
} catch (IOException e) {
e.printStackTrace();
return false;
}
// 原圖的大小
int width = srcImage.getWidth() / proportion;
int hight = srcImage.getHeight() / proportion;
srcImage = resize(srcImage, width, hight);
// 縮放後的影象的寬和高
int w = srcImage.getWidth();
int h = srcImage.getHeight();
// 如果縮放後的影象和要求的影象寬度一樣，就對縮放的影象的高度進行擷取
if (w == width) {
// 計算X軸座標
int x = 0;
int y = h / 2 - hight / 2;
try {
saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile);
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
// 否則如果是縮放後的影象的高度和要求的影象高度一樣，就對縮放後的影象的寬度進行擷取
else if (h == hight) {
// 計算X軸座標
int x = w / 2 - width / 2;
int y = 0;
try {
saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile);
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
return true;
}
/**
* 實現縮放後的截圖
* @param image 縮放後的影象
* @param subImageBounds 要擷取的子圖的範圍
* @param subImageFile 要儲存的檔案
* @throws IOException
*/
private static void saveSubImage(BufferedImage image,
Rectangle subImageBounds, File subImageFile) throws IOException {
if (subImageBounds.x < 0 || subImageBounds.y < 0
|| subImageBounds.width - subImageBounds.x > image.getWidth()
|| subImageBounds.height - subImageBounds.y > image.getHeight()) {
LoggerUtil.error(ImageHelper.class, "Bad subimage bounds");
return;
}
BufferedImage subImage = image.getSubimage(subImageBounds.x,subImageBounds.y, subImageBounds.width, subImageBounds.height);
String fileName = subImageFile.getName();
String formatName = fileName.substring(fileName.lastIndexOf('.') + 1);
ImageIO.write(subImage, formatName, subImageFile);
}
public static void main(String[] args) throws Exception {
/**
* saveSubImage 截圖類的使用
* srcImage 為BufferedImage物件
* Rectangle 為需要截圖的長方形座標
* saveFile 需要儲存的路徑及名稱
* **/
//需要截圖的長方形座標
/*Rectangle rect =new Rectangle();
rect.x=40;
rect.y=40;
rect.height=160;
rect.width=160;
InputStream in = null;
//需要儲存的路徑及名稱
File saveFile = new File("d:\\kec3.jpg");
//需要進行處理的圖片的路徑
in = new FileInputStream(new File("d:\\kec.jpg"));
BufferedImage srcImage = null;
//將輸入的資料轉為BufferedImage物件
srcImage = ImageIO.read(in);
ImageHelper img=new ImageHelper();
img.saveSubImage(srcImage, rect, saveFile);*/
/**
* compress 圖片縮放類的使用(縮圖)
* srcImage 為InputStream物件
* Rectangle 為需要截圖的長方形座標
* proportion 為壓縮比例
* **/
/*InputStream in = null;
//縮放後需要儲存的路徑
File saveFile = new File("d:\\kec2.jpg");
try {
//原圖片的路徑
in = new FileInputStream(new File("d:\\kec.jpg"));
compress(in, saveFile, 5);
} catch (Exception e) {
e.printStackTrace();
} finally {
in.close();
}*/
}
}