图片缩小 指定宽和高或按比例缩放
package com.happigo.grab; /** * write by enter2000.com */ import java.awt.image.BufferedImage; import java.io.BufferedInputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.net.HttpURLConnection; import java.net.URL; import javax.imageio.ImageIO; public class ImageScale { private int width; private int height; private int scaleWidth; double support = (double) 3.0; double[] contrib; double[] normContrib; double[] tmpContrib; int startContrib, stopContrib; int nDots; int nHalfDots; public BufferedImage imageZoomOut(BufferedImage srcBufferImage, int w, int h, boolean lockScale) { width = srcBufferImage.getWidth(); height = srcBufferImage.getHeight(); scaleWidth = w; if (lockScale) { h = w * height / width; } if (DetermineResultSize(w, h) == 1) { return srcBufferImage; } CalContrib(); BufferedImage pbOut = HorizontalFiltering(srcBufferImage, w); BufferedImage pbFinalOut = VerticalFiltering(pbOut, h); return pbFinalOut; } /** * 决定图像尺寸 */ private int DetermineResultSize(int w, int h) { double scaleH, scaleV; scaleH = (double) w / (double) width; scaleV = (double) h / (double) height; // 需要判断一下scaleH，scaleV，不做放大操作 if (scaleH >= 1.0 && scaleV >= 1.0) { return 1; } return 0; } // end of DetermineResultSize() private double Lanczos(int i, int inWidth, int outWidth, double Support) { double x; x = (double) i * (double) outWidth / (double) inWidth; return Math.sin(x * Math.PI) / (x * Math.PI) * Math.sin(x * Math.PI / Support) / (x * Math.PI / Support); } // end of Lanczos() // // Assumption: same horizontal and vertical scaling factor // 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]; } } // end of CalContrib() // 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; } } // end of CalTempContrib() 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; } // end of HorizontalFilter() // 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; } // end of HorizontalFiltering() 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)); // System.out.println(valueRGB); return valueRGB; } // end of VerticalFilter() 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; } // end of VerticalFiltering() int Clip(int x) { if (x < 0) return 0; if (x > 255) return 255; return x; } public void saveToFile(String imageUrl, String saveUrl) { FileOutputStream fos = null; BufferedInputStream bis = null; HttpURLConnection httpUrl = null; URL url = null; int BUFFER_SIZE = 1024*10; byte[] buf = new byte[BUFFER_SIZE]; int size = 0; try { File file = new File(saveUrl); File parent = file.getParentFile(); if (parent != null && !parent.exists()) { parent.mkdirs(); } url = new URL(imageUrl); httpUrl = (HttpURLConnection) url.openConnection(); httpUrl.connect(); bis = new BufferedInputStream(httpUrl.getInputStream()); fos = new FileOutputStream(saveUrl); while ((size = bis.read(buf)) != -1) { fos.write(buf, 0, size); } fos.flush(); } catch (IOException e) { } catch (ClassCastException e) { } finally { try { fos.close(); bis.close(); httpUrl.disconnect(); } catch (IOException e) { } catch (NullPointerException e) { } } } /** * 处理10M内的图像数据 * @param fromUrl * 源图片地址 * @param saveUrl * 保存地址 * @param imageW * 图片宽度（默认200） * @param imageH * 图片高度（默认200） * @param lockScale * 等比缩放 * @return */ public String dealImage(String fromUrl, String saveUrl, int imageW, int imageH, boolean lockScale) { if (imageW == 0) imageW = 200; if (imageH == 0) imageH = 200; try { saveToFile(fromUrl, saveUrl); BufferedImage image1; image1 = ImageIO.read(new File(saveUrl)); BufferedImage image2 = imageZoomOut(image1, imageW, imageH, lockScale); FileOutputStream out = new FileOutputStream(saveUrl); ImageIO.write(image2, "jpg", out); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return ""; } public static void main(String[] args) throws IOException { ImageScale is = new ImageScale(); String fromUrl = "http://g3.happimg.com/2012/1129/16/s1_90378.jpg"; String saveUrl = "c:\\t1222_100.jpg"; is.dealImage(fromUrl, saveUrl, 100, 400,true); System.out.println("图片处理完成"); } }
单独图片下载
package com.happigo.grab; import java.io.BufferedInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.net.HttpURLConnection; import java.net.URL; public class downimage { public void saveToFile(String destUrl) { FileOutputStream fos = null; BufferedInputStream bis = null; HttpURLConnection httpUrl = null; URL url = null; int BUFFER_SIZE = 1024; byte[] buf = new byte[BUFFER_SIZE]; int size = 0; try { url = new URL(destUrl); httpUrl = (HttpURLConnection) url.openConnection(); httpUrl.connect(); bis = new BufferedInputStream(httpUrl.getInputStream()); fos = new FileOutputStream("c:\\haha.gif"); while ((size = bis.read(buf)) != -1) { fos.write(buf, 0, size); } fos.flush(); } catch (IOException e) { } catch (ClassCastException e) { } finally { try { fos.close(); bis.close(); httpUrl.disconnect(); } catch (IOException e) { } catch (NullPointerException e) { } } } public static void main(String[] args) { // TODO Auto-generated method stub downimage dw = new downimage(); dw.saveToFile("http://wx.qlogo.cn/mmopen/ajNVdqHZLLBsjJx0OgFI5nmhg2J5PCdUnqoib9jT4AJvxXOsicTpxomH8GXXgUj89hCvvXPWuHP1mibCkP0USzXibQ/0"); } }