java 双立方差值+调用方法 +java自带的图片压缩方法
BiCubicInterpolationScale.java
package com.util;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.MemoryImageSource;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import javax.imageio.ImageIO;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class BiCubicInterpolationScale {
private static double a00, a01, a02, a03;
private static double a10, a11, a12, a13;
private static double a20, a21, a22, a23;
private static double a30, a31, a32, a33;
private static int srcWidth;
private static int srcHeight;
/**
* 双立方插值
* @param inPixelsData 像素矩阵数组
* @param srcW 原图像的宽
* @param srcH 原图像的高
* @param destW 目标图像的宽
* @param destH 目标图像的高
* @return 处理后的推三矩阵数组
*/
public static int[] imgScale(int[] inPixelsData, int srcW, int srcH, int destW, int destH) {
double[][][] input3DData = processOneToThreeDeminsion(inPixelsData, srcH, srcW);
int[][][] outputThreeDeminsionData = new int[destH][destW][4];
double[][] tempPixels = new double[4][4];
float rowRatio = ((float)srcH)/((float)destH);
float colRatio = ((float)srcW)/((float)destW);
srcWidth = srcW;
srcHeight = srcH;
for(int row=0; row<destH; row++) {
// convert to three dimension data
double srcRow = ((float)row)*rowRatio;
double j = Math.floor(srcRow);
double t = srcRow - j;
for(int col=0; col<destW; col++) {
double srcCol = ((float)col)*colRatio;
double k = Math.floor(srcCol);
double u = srcCol - k;
for(int i=0; i<4; i++) {
tempPixels[0][0] = getRGBValue(input3DData,j-1, k-1,i);
tempPixels[0][1] = getRGBValue(input3DData,j-1, k, i);
tempPixels[0][2] = getRGBValue(input3DData, j-1,k+1, i);
tempPixels[0][3] = getRGBValue(input3DData, j-1, k+2,i);
tempPixels[1][0] = getRGBValue(input3DData, j, k-1, i);
tempPixels[1][1] = getRGBValue(input3DData, j, k, i);
tempPixels[1][2] = getRGBValue(input3DData, j, k+1, i);
tempPixels[1][3] = getRGBValue(input3DData, j, k+2, i);
tempPixels[2][0] = getRGBValue(input3DData, j+1,k-1,i);
tempPixels[2][1] = getRGBValue(input3DData, j+1, k, i);
tempPixels[2][2] = getRGBValue(input3DData, j+1, k+1, i);
tempPixels[2][3] = getRGBValue(input3DData, j+1, k+2, i);
tempPixels[3][0] = getRGBValue(input3DData, j+2, k-1, i);
tempPixels[3][1] = getRGBValue(input3DData, j+2, k, i);
tempPixels[3][2] = getRGBValue(input3DData, j+2, k+1, i);
tempPixels[3][3] = getRGBValue(input3DData, j+2, k+2, i);
// update coefficients
updateCoefficients(tempPixels);
outputThreeDeminsionData[row][col][i] = getPixelValue(getValue(t, u));
}
}
}
return convertToOneDim(outputThreeDeminsionData, destW, destH);
}
private static double getRGBValue(double[][][] input3DData, double row, double col, int index) {
if(col >= srcWidth) {
col = srcWidth - 1;
}
if(col < 0) {
col = 0;
}
if(row >= srcHeight) {
row = srcHeight - 1;
}
if(row < 0) {
row = 0;
}
return input3DData[(int)row][(int)col][index];
}
private static int getPixelValue(double pixelValue) {
return pixelValue < 0 ? 0: pixelValue >255.0d ?255:(int)pixelValue;
}
private static void updateCoefficients (double[][] p) {
a00 = p[1][1];
a01 = -.5*p[1][0] + .5*p[1][2];
a02 = p[1][0] - 2.5*p[1][1] + 2*p[1][2] - .5*p[1][3];
a03 = -.5*p[1][0] + 1.5*p[1][1] - 1.5*p[1][2] + .5*p[1][3];
a10 = -.5*p[0][1] + .5*p[2][1];
a11 = .25*p[0][0] - .25*p[0][2] - .25*p[2][0] + .25*p[2][2];
a12 = -.5*p[0][0] + 1.25*p[0][1] - p[0][2] + .25*p[0][3] + .5*p[2][0] - 1.25*p[2][1] + p[2][2] - .25*p[2][3];
a13 = .25*p[0][0] - .75*p[0][1] + .75*p[0][2] - .25*p[0][3] - .25*p[2][0] + .75*p[2][1] - .75*p[2][2] + .25*p[2][3];
a20 = p[0][1] - 2.5*p[1][1] + 2*p[2][1] - .5*p[3][1];
a21 = -.5*p[0][0] + .5*p[0][2] + 1.25*p[1][0] - 1.25*p[1][2] - p[2][0] + p[2][2] + .25*p[3][0] - .25*p[3][2];
a22 = p[0][0] - 2.5*p[0][1] + 2*p[0][2] - .5*p[0][3] - 2.5*p[1][0] + 6.25*p[1][1] - 5*p[1][2] + 1.25*p[1][3] + 2*p[2][0] - 5*p[2][1] + 4*p[2][2] - p[2][3] - .5*p[3][0] + 1.25*p[3][1] - p[3][2] + .25*p[3][3];
a23 = -.5*p[0][0] + 1.5*p[0][1] - 1.5*p[0][2] + .5*p[0][3] + 1.25*p[1][0] - 3.75*p[1][1] + 3.75*p[1][2] - 1.25*p[1][3] - p[2][0] + 3*p[2][1] - 3*p[2][2] + p[2][3] + .25*p[3][0] - .75*p[3][1] + .75*p[3][2] - .25*p[3][3];
a30 = -.5*p[0][1] + 1.5*p[1][1] - 1.5*p[2][1] + .5*p[3][1];
a31 = .25*p[0][0] - .25*p[0][2] - .75*p[1][0] + .75*p[1][2] + .75*p[2][0] - .75*p[2][2] - .25*p[3][0] + .25*p[3][2];
a32 = -.5*p[0][0] + 1.25*p[0][1] - p[0][2] + .25*p[0][3] + 1.5*p[1][0] - 3.75*p[1][1] + 3*p[1][2] - .75*p[1][3] - 1.5*p[2][0] + 3.75*p[2][1] - 3*p[2][2] + .75*p[2][3] + .5*p[3][0] - 1.25*p[3][1] + p[3][2] - .25*p[3][3];
a33 = .25*p[0][0] - .75*p[0][1] + .75*p[0][2] - .25*p[0][3] - .75*p[1][0] + 2.25*p[1][1] - 2.25*p[1][2] + .75*p[1][3] + .75*p[2][0] - 2.25*p[2][1] + 2.25*p[2][2] - .75*p[2][3] - .25*p[3][0] + .75*p[3][1] - .75*p[3][2] + .25*p[3][3];
}
private static double getValue (double x, double y) {
double x2 = x * x;
double x3 = x2 * x;
double y2 = y * y;
double y3 = y2 * y;
return (a00 + a01 * y + a02 * y2 + a03 * y3) +
(a10 + a11 * y + a12 * y2 + a13 * y3) * x +
(a20 + a21 * y + a22 * y2 + a23 * y3) * x2 +
(a30 + a31 * y + a32 * y2 + a33 * y3) * x3;
}
/* <p> The purpose of this method is to convert the data in the 3D array of ints back into </p>
* <p> the 1d array of type int. </p>
*
*/
private static int[] convertToOneDim(int[][][] data, int imgCols, int imgRows) {
// Create the 1D array of type int to be populated with pixel data
int[] oneDPix = new int[imgCols * imgRows * 4];
// Move the data into the 1D array. Note the
// use of the bitwise OR operator and the
// bitwise left-shift operators to put the
// four 8-bit bytes into each int.
for (int row = 0, cnt = 0; row < imgRows; row++) {
for (int col = 0; col < imgCols; col++) {
oneDPix[cnt] = ((data[row][col][0] << 24) & 0xFF000000)
| ((data[row][col][1] << 16) & 0x00FF0000)
| ((data[row][col][2] << 8) & 0x0000FF00)
| ((data[row][col][3]) & 0x000000FF);
cnt++;
}// end for loop on col
}// end for loop on row
return oneDPix;
}// end convertToOneDim
private static double [][][] processOneToThreeDeminsion(int[] oneDPix2, int imgRows, int imgCols) {
double[][][] tempData = new double[imgRows][imgCols][4];
for(int row=0; row<imgRows; row++) {
// per row processing
int[] aRow = new int[imgCols];
for (int col = 0; col < imgCols; col++) {
int element = row * imgCols + col;
aRow[col] = oneDPix2[element];
}
// convert to three dimension data
for(int col=0; col<imgCols; col++) {
tempData[row][col][0] = (aRow[col] >> 24) & 0xFF; // alpha
tempData[row][col][1] = (aRow[col] >> 16) & 0xFF; // red
tempData[row][col][2] = (aRow[col] >> 8) & 0xFF; // green
tempData[row][col][3] = (aRow[col]) & 0xFF; // blue
}
}
return tempData;
}
public static void main(String args[]) throws IOException {
BufferedImage img = ImageIO.read(new File("E:\\test\\123.jpg"));
int imageType = img.getType();
int w = img.getWidth();
int h = img.getHeight();
int[] pix = new int[w*h];
pix = img.getRGB(0, 0, w, h, pix, 0, w);
int targetW=w*10;
int targetH=h*10;
int[] newArray =imgScale(pix, w, h, targetW, targetH);
System.out.println(imageType);
File out = new File("e:\\abc.jpg");
if (!out.exists())
out.createNewFile();
OutputStream output = new FileOutputStream(out);
BufferedImage imgOut = new BufferedImage(targetW, targetH, imageType);
imgOut.setRGB(0, 0, targetW, targetH, newArray, 0, targetW);
ImageIO.write(imgOut, "jpg", output);
}
}
下面是java自带的图片压缩方法
package com.util;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.imageio.ImageIO;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class ztest{
public static void main(String[] args) {
reduceImg("e:\\1.jpg", "e:\\test\\123.jpg",10);
}
public static void reduceImg(String imgsrc, String imgdist,int times) {
try {
File srcfile = new File(imgsrc);
if (!srcfile.exists()) {
return;
}
Image src = javax.imageio.ImageIO.read(srcfile);
BufferedImage img = ImageIO.read(new File(imgsrc));
int distW=img.getWidth()/times;
int distH=img.getHeight()/times;
System.out.println(distW);
System.out.println(distH);
BufferedImage tag= new BufferedImage( distW, distH,img.getType());
//image.SCALE_SMOOTH //平滑优先
//image.SCALE_FAST//速度优先
// image.SCALE_AREA_AVERAGING //区域均值
// image.SCALE_REPLICATE //像素复制型缩放
// image.SCALE_DEFAULT //默认缩放模式
tag.getGraphics().drawImage(src.getScaledInstance(distW, distH, Image.SCALE_SMOOTH), 0, 0, null);
FileOutputStream out = new FileOutputStream(imgdist);
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(tag);
out.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}