求一个比较好的jpg图片高宽调整代码
以下是我现在使用的一段调整高宽的代码,但是他的效率,实在是,太低了,虽然最后调整后的图片质量很高,但是还是受不了他的效率,请问有没有比较好的且效率很高的代码,或者有关的库?麻烦顺便贴出使用方法,谢谢,谢谢~
- Java code
package cn.hlgc.util;
import java.awt.image.BufferedImage;
import org.apache.log4j.Logger;
public class ResizePicUtil {
private int width;
private int height;
private int scaleWidth;
double support = (double) 3.0;
double PI = (double) 3.14159265358978;
double[] contrib;
double[] normContrib;
double[] tmpContrib;
int startContrib, stopContrib;
int nDots;
int nHalfDots;
private static Logger logger = Logger.getLogger(ResizePicUtil.class);
public BufferedImage imageZoomOut(BufferedImage srcBufferImage, int w, int h) {
width = srcBufferImage.getWidth();
height = srcBufferImage.getHeight();
scaleWidth = w;
logger.info("原图宽度为[" + width + "px]...");
logger.info("原图高度为[" + height + "px]...");
if (DetermineResultSize(w, h) == 1) {
logger.info("不需要将图片进行缩小...");
return srcBufferImage;
}
logger.info("计算缩小图片的宽度和高度...");
double wh = ((double) width) / ((double) height);
double hw = ((double) height) / ((double) width);
if (wh > hw) {
h = (int) (w * hw);
} else {
w = (int) (h * wh);
}
logger.info("图片宽度调整为[" + w + "px]...");
logger.info("图片高度调整为[" + h + "px]...");
long begin = System.currentTimeMillis();
CalContrib();
BufferedImage pbOut = HorizontalFiltering(srcBufferImage, w);
BufferedImage pbFinalOut = VerticalFiltering(pbOut, h);
long end = System.currentTimeMillis();
logger.info("图片高宽调整完毕,耗时[" + (end - begin) + "]毫秒...");
return pbFinalOut;
}
private int DetermineResultSize(int w, int h) {
double scaleH, scaleV;
scaleH = (double) w / (double) width;
scaleV = (double) h / (double) height;
if (scaleH >= 1.0 && scaleV >= 1.0) {
return 1;
}
return 0;
}
private double Lanczos(int i, int inWidth, int outWidth, double Support) {
double x;
x = (double) i * (double) outWidth / (double) inWidth;
return Math.sin(x * PI) / (x * PI) * Math.sin(x * PI / Support)
/ (x * PI / Support);
}
private void CalContrib() {
nHalfDots = (int) ((double) width * support / (double) scaleWidth);
nDots = nHalfDots * 2 + 1;
try {
contrib = new double[nDots];
normContrib = new double[nDots];
tmpContrib = new double[nDots];
} catch (Exception e) {
System.out.println("init contrib,normContrib,tmpContrib" + e);
}
int center = nHalfDots;
contrib[center] = 1.0;
double weight = 0.0;
int i = 0;
for (i = 1; i <= center; i++) {
contrib[center + i] = Lanczos(i, width, scaleWidth, support);
weight += contrib[center + i];
}
for (i = center - 1; i >= 0; i--) {
contrib[i] = contrib[center * 2 - i];
}
weight = weight * 2 + 1.0;
for (i = 0; i <= center; i++) {
normContrib[i] = contrib[i] / weight;
}
for (i = center + 1; i < nDots; i++) {
normContrib[i] = normContrib[center * 2 - i];
}
}
// 处理边缘
private void CalTempContrib(int start, int stop) {
double weight = 0;
int i = 0;
for (i = start; i <= stop; i++) {
weight += contrib[i];
}
for (i = start; i <= stop; i++) {
tmpContrib[i] = contrib[i] / weight;
}
}
private int GetRedValue(int rgbValue) {
int temp = rgbValue & 0x00ff0000;
return temp >> 16;
}
private int GetGreenValue(int rgbValue) {
int temp = rgbValue & 0x0000ff00;
return temp >> 8;
}
private int GetBlueValue(int rgbValue) {
return rgbValue & 0x000000ff;
}
private int ComRGB(int redValue, int greenValue, int blueValue) {
return (redValue < < 16) + (greenValue < < 8) + blueValue;
}
// 行水平滤波
private int HorizontalFilter(BufferedImage bufImg, int startX, int stopX,
int start, int stop, int y, double[] pContrib) {
double valueRed = 0.0;
double valueGreen = 0.0;
double valueBlue = 0.0;
int valueRGB = 0;
int i, j;
for (i = startX, j = start; i <= stopX; i++, j++) {
valueRGB = bufImg.getRGB(i, y);
valueRed += GetRedValue(valueRGB) * pContrib[j];
valueGreen += GetGreenValue(valueRGB) * pContrib[j];
valueBlue += GetBlueValue(valueRGB) * pContrib[j];
}
valueRGB = ComRGB(Clip((int) valueRed), Clip((int) valueGreen),
Clip((int) valueBlue));
return valueRGB;
}
// 图片水平滤波
private BufferedImage HorizontalFiltering(BufferedImage bufImage, int iOutW) {
int dwInW = bufImage.getWidth();
int dwInH = bufImage.getHeight();
int value = 0;
BufferedImage pbOut = new BufferedImage(iOutW, dwInH,
BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < iOutW; x++) {
int startX;
int start;
int X = (int) (((double) x) * ((double) dwInW) / ((double) iOutW) + 0.5);
int y = 0;
startX = X - nHalfDots;
if (startX < 0) {
startX = 0;
start = nHalfDots - X;
} else {
start = 0;
}
int stop;
int stopX = X + nHalfDots;
if (stopX > (dwInW - 1)) {
stopX = dwInW - 1;
stop = nHalfDots + (dwInW - 1 - X);
} else {
stop = nHalfDots * 2;
}
if (start > 0 || stop < nDots - 1) {
CalTempContrib(start, stop);
for (y = 0; y < dwInH; y++) {
value = HorizontalFilter(bufImage, startX, stopX, start,
stop, y, tmpContrib);
pbOut.setRGB(x, y, value);
}
} else {
for (y = 0; y < dwInH; y++) {
value = HorizontalFilter(bufImage, startX, stopX, start,
stop, y, normContrib);
pbOut.setRGB(x, y, value);
}
}
}
return pbOut;
}
private int VerticalFilter(BufferedImage pbInImage, int startY, int stopY,
int start, int stop, int x, double[] pContrib) {
double valueRed = 0.0;
double valueGreen = 0.0;
double valueBlue = 0.0;
int valueRGB = 0;
int i, j;
for (i = startY, j = start; i <= stopY; i++, j++) {
valueRGB = pbInImage.getRGB(x, i);
valueRed += GetRedValue(valueRGB) * pContrib[j];
valueGreen += GetGreenValue(valueRGB) * pContrib[j];
valueBlue += GetBlueValue(valueRGB) * pContrib[j];
}
valueRGB = ComRGB(Clip((int) valueRed), Clip((int) valueGreen),
Clip((int) valueBlue));
return valueRGB;
}
private BufferedImage VerticalFiltering(BufferedImage pbImage, int iOutH) {
int iW = pbImage.getWidth();
int iH = pbImage.getHeight();
int value = 0;
BufferedImage pbOut = new BufferedImage(iW, iOutH,
BufferedImage.TYPE_INT_RGB);
for (int y = 0; y < iOutH; y++) {
int startY;
int start;
int Y = (int) (((double) y) * ((double) iH) / ((double) iOutH) + 0.5);
startY = Y - nHalfDots;
if (startY < 0) {
startY = 0;
start = nHalfDots - Y;
} else {
start = 0;
}
int stop;
int stopY = Y + nHalfDots;
if (stopY > (int) (iH - 1)) {
stopY = iH - 1;
stop = nHalfDots + (iH - 1 - Y);
} else {
stop = nHalfDots * 2;
}
if (start > 0 || stop < nDots - 1) {
CalTempContrib(start, stop);
for (int x = 0; x < iW; x++) {
value = VerticalFilter(pbImage, startY, stopY, start, stop,
x, tmpContrib);
pbOut.setRGB(x, y, value);
}
} else {
for (int x = 0; x < iW; x++) {
value = VerticalFilter(pbImage, startY, stopY, start, stop,
x, normContrib);
pbOut.setRGB(x, y, value);
}
}
}
return pbOut;
}
int Clip(int x) {
if (x < 0)
return 0;
if (x > 255)
return 255;
return x;
}
}
[解决办法]
帮你顶一下
[解决办法]
[解决办法]
我以前做格式转换的时候用过JAI还可以。JAR包在SUN的网站上可以下载到。
- Java code
package com.mop.pushmail.adapter.image;import javax.media.jai.operator.*;import javax.media.jai.iterator.*;import javax.media.jai.operator.*;import javax.media.jai.*;import com.sun.media.jai.codec.*;import java.awt.image.renderable.*;import java.awt.image.*;import java.io.File;import java.io.FileOutputStream;public class imgutil { public boolean smallpicture(String src, String dest, int w, int h) { try { ParameterBlockJAI loadPB = new ParameterBlockJAI("fileload"); loadPB.setParameter("filename", src); PlanarImage source = JAI.create("fileload", loadPB); int orinWidth = source.getWidth(); int orinHeigth = source.getHeight(); int newHeigth = orinHeigth; int newWidth = orinWidth; //处理图片大小缩放 if ((orinHeigth > h) || (orinWidth > w)) { if (orinHeigth > orinWidth) { newHeigth = orinHeigth * h / orinHeigth; newWidth = orinWidth * w / orinHeigth; } else { newHeigth = orinHeigth * h / orinWidth; newWidth = orinWidth * w / orinWidth; } } ParameterBlock pb = new ParameterBlock(); pb.addSource(source); RenderableImage ren = JAI.createRenderable("renderable", pb); PlanarImage dst = (PlanarImage) ren.createScaledRendering(newWidth, newHeigth, null); File fout = new File(dest); FileOutputStream out = new FileOutputStream(fout); JPEGEncodeParam param = new JPEGEncodeParam(); param.setQuality(0.70f);//设置图片质量 //这里你可以选择不同的图片编码，不过gif因为版权问题要压缩成png ImageEncoder encoder = ImageCodec.createImageEncoder("JPEG", out, param); encoder.encode(dst); out.close(); return true; } catch (Exception e) { //e.printStackTrace(); return false; } } public static void main(String[] args) { imgutil im = new imgutil(); long s = System.currentTimeMillis(); System.out.println("start:" + s); im.smallpicture("E://vladstudio_5001.tiff","E://2.jpg",200,300); long e = System.currentTimeMillis(); System.out.println("end:" + e); System.out.println("相差:" + (float)(e-s)/1000); } }
[解决办法]
用 java.awt.Image 类的方法：
public Image getScaledInstance(int width, int height, int hints)
创建此图像的缩放版本。返回一个新的 Image 对象，默认情况下，该对象按指定的 width 和 height 呈现图像。即使已经完全加载了初始源图像，新的 Image 对象也可以被异步加载。
如果 width 或 height 为负数，则替换该值以维持初始图像尺寸的高宽比。如果 width 和 height 都为负，则使用初始图像尺寸。
参数：
width - 将图像缩放到的宽度。
height - 将图像缩放到的高度。
hints - 指示用于图像重新取样的算法类型的标志。
返回：
图像的缩放版本。