Here you can find the source of ScaleToSize(BufferedImage bimg, int maxCols, int maxRows)
public static BufferedImage ScaleToSize(BufferedImage bimg, int maxCols, int maxRows)
//package com.java2s; //License from project: Apache License import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Image; import java.awt.RenderingHints; import java.awt.geom.AffineTransform; import java.awt.image.AffineTransformOp; import java.awt.image.BufferedImage; import java.io.BufferedInputStream; import java.io.File; import java.io.IOException; import java.util.Iterator; import javax.imageio.IIOImage; import javax.imageio.ImageIO; import javax.imageio.ImageWriteParam; import javax.imageio.ImageWriter; import javax.imageio.stream.FileImageOutputStream; import javax.swing.ImageIcon; public class Main { static int COLORTYPE = BufferedImage.TYPE_INT_ARGB; public static BufferedImage ScaleToSize(Image srcImg, int w, int h) { if (w == -1) w = srcImg.getWidth(null);//from w w w . ja v a2 s. c o m if (h == -1) h = srcImg.getHeight(null); if (w == -1 || h == -1) { srcImg = new ImageIcon(srcImg).getImage(); w = srcImg.getWidth(null); h = srcImg.getHeight(null); } System.out.println("AWT Image Wt: " + w + " And Ht: " + h); BufferedImage buffImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB); Graphics2D g2 = buffImg.createGraphics(); g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR); g2.drawImage(srcImg, 0, 0, null); g2.dispose(); return buffImg; } public static BufferedImage ScaleToSize(String inFileName, int maxCols, int maxRows, String outFileName, String format) { BufferedImage img = LoadImage(inFileName); BufferedImage altImg = ScaleToSize(img, maxCols, maxRows); SaveImageToFile(altImg, outFileName, format); return altImg; } public static BufferedImage ScaleToSize(BufferedImage bimg, int maxCols, int maxRows) { if (maxCols == -1) maxCols = bimg.getWidth(null); if (maxRows == -1) maxRows = bimg.getHeight(null); if (maxCols == -1 || maxRows == -1) { Image srcImg = new ImageIcon(bimg).getImage(); maxCols = srcImg.getWidth(null); maxRows = srcImg.getHeight(null); } BufferedImage bimgnew = new BufferedImage(maxCols, maxRows, COLORTYPE); Graphics g = bimgnew.createGraphics(); g.drawImage(bimg, 0, 0, maxCols, maxRows, null); // g.drawImage(bimg, 0, 0, null); g.dispose(); return (bimgnew); } public static void drawImage(BufferedImage srcImg, BufferedImage img2Draw, int w, int h) { if (w == -1) w = (int) (srcImg.getWidth() / 2); if (h == -1) h = (int) (srcImg.getHeight() / 2); System.out.println("AWT Image Wt: " + w + " And Ht: " + h); Graphics2D g2 = srcImg.createGraphics(); g2.drawImage(img2Draw, w, h, null); g2.dispose(); } public static byte[] loadImage(String imgPath, Class caller) { int MAX_IMAGE_SIZE = 2400; // Change this to the size of // your biggest image, in bytes. byte buf[] = null; int count = 0; System.out.println("Load Image Stream: " + imgPath); BufferedInputStream imgStream = null; imgStream = new BufferedInputStream(caller.getResourceAsStream(imgPath)); if (imgStream == null) { System.err.println("Couldn't find file: " + imgPath); return null; } // Creating the Image Icon from the stream try { System.out.println("Image Stream is Not Null: " + imgStream); System.out.println("Image Stream 4: " + imgPath + " is: " + imgStream.available()); buf = new byte[imgStream.available()]; count = imgStream.read(buf, 0, buf.length); System.out.println("Buffered Size: " + buf.length + " count: " + count); imgStream.close(); } catch (IOException ioe) { System.err.println("Couldn't read stream from file: " + imgPath); return null; } catch (Throwable th) { th.printStackTrace(); System.out.println("Cought Exception while reading stream"); return null; } if (count <= 0) { System.err.println("Empty file: " + imgPath); return null; } return buf; } public static Image loadImage(byte[] imgStr, int imageSize) { ImageIcon imgIcon = new ImageIcon(imgStr); if (imgIcon == null) return null; return getScaledImage(imgIcon.getImage(), imageSize); } public static Image loadImage(String filePath, int imageSize) { ImageIcon imgIcon = new ImageIcon(filePath); if (imgIcon == null) return null; return getScaledImage(imgIcon.getImage(), imageSize); } public static BufferedImage LoadImage(String filename) { return LoadImage(new File(filename)); } public static BufferedImage LoadImage(File imgFile) { BufferedImage bimg = null; try { System.out.println("Image File Size: " + imgFile.length()); bimg = ImageIO.read(imgFile); } catch (Exception e) { System.out.println("Exception at LoadImage"); e.printStackTrace(); } return bimg; } public static void SaveImageToFile(Image img, String filename, String outformat) { BufferedImage bimg = ScaleToSize(img, -1, -1); if (outformat.equalsIgnoreCase("JPEG") || outformat.equalsIgnoreCase("JPG")) SaveJPEG(bimg, new File(filename)); else SaveImageToFile(bimg, filename, outformat); } public static void SaveImageToFile(BufferedImage bimg, String filename, String outformat) { File f = new File(filename); if (outformat.equalsIgnoreCase("JPEG") || outformat.equalsIgnoreCase("JPG")) SaveJPEG(bimg, f); else SaveImageToFile(bimg, f, outformat); } public static void SaveImageToFile(BufferedImage bimg, File f, String outformat) { if (outformat.equalsIgnoreCase("JPEG") || outformat.equalsIgnoreCase("JPG")) SaveJPEG(bimg, f); try { ImageIO.write(bimg, outformat, f); } catch (Exception e) { System.out.println("SaveImage"); e.printStackTrace(); } } public static Image getScaledImage(Image image, int imageSize) { if (imageSize == -1 || image.getWidth(null) <= imageSize) return image; // Reseampling the Image to create Thumbview. The getScaledInstance // method // maintains the Aspect Ratio. image = image.getScaledInstance(imageSize, -1, Image.SCALE_DEFAULT); return image; } public static void SaveJPEG(BufferedImage bimg, File file) { // *********************** For JPEG output files, this code is required. AffineTransform s = new AffineTransform(); AffineTransformOp sop = new AffineTransformOp(s, AffineTransformOp.TYPE_NEAREST_NEIGHBOR); BufferedImage jpgimage = new BufferedImage(bimg.getWidth(), bimg.getHeight(), BufferedImage.TYPE_INT_RGB); sop.filter(bimg, jpgimage); // ********************************************************* Iterator iter = ImageIO.getImageWritersByFormatName("jpeg"); ImageWriter writer = (ImageWriter) iter.next(); // instantiate an ImageWriteParam object with default compression // options ImageWriteParam iwp = writer.getDefaultWriteParam(); iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT); iwp.setCompressionQuality(1); // an integer between 0 and 1 // 1 specifies minimum compression and maximum quality try { FileImageOutputStream output = new FileImageOutputStream(file); writer.setOutput(output); IIOImage image = new IIOImage(jpgimage, null, null); writer.write(null, image, iwp); output.close(); } catch (Exception e) { System.out.println("SaveJPEG"); e.printStackTrace(); } } }