tim/prune/gui/ImageUtils.java

   1 package tim.prune.gui;
   2
   3 import java.awt.Dimension;
   4 import java.awt.Graphics;
   5 import java.awt.Image;
   6 import java.awt.image.BufferedImage;
   7 import java.awt.image.ConvolveOp;
   8 import java.awt.image.Kernel;
   9
  10 import javax.swing.ImageIcon;
  11
  12 /**
  13  * Class for providing generic image processing functions
  14  */
  15 public abstract class ImageUtils
  16 {
  17         private static final float SMOOTH_FACTOR = 0.008f;
  18         private static ConvolveOp CONVOLVER = null;
  19
  20         /** Static block for initialization */
  21         static
  22         {
  23                 float[] smoothMatrix = {
  24                         0, SMOOTH_FACTOR, 0,
  25                         SMOOTH_FACTOR, 1-(SMOOTH_FACTOR*4), SMOOTH_FACTOR,
  26                         0, SMOOTH_FACTOR, 0
  27                 };
  28                 CONVOLVER = new ConvolveOp(new Kernel(3, 3, smoothMatrix));
  29         }
  30
  31
  32         /**
  33          * Create a scaled and smoothed image according to the specified size
  34          * @param inImage image to scale
  35          * @param inWidth width to scale to
  36          * @param inHeight height to scale to
  37          * @return BufferedImage containing scaled result
  38          */
  39         public static BufferedImage createScaledImage(Image inImage, int inWidth, int inHeight)
  40         {
  41                 // create smaller image and force its loading
  42                 Image smallerImage = inImage.getScaledInstance(inWidth, inHeight, Image.SCALE_SMOOTH);
  43                 Image tempImage = new ImageIcon(smallerImage).getImage();
  44                 tempImage.getWidth(null);
  45
  46                 // create buffered image to do transform
  47                 BufferedImage buffer = new BufferedImage(inWidth, inHeight, BufferedImage.TYPE_INT_RGB);
  48                 // copy scaled picture into buffer
  49                 Graphics buffG = buffer.getGraphics();
  50                 buffG.drawImage(smallerImage, 0, 0, inWidth, inHeight, null);
  51                 buffG.dispose();
  52
  53                 // clear variables
  54                 smallerImage = null; tempImage = null;
  55                 // smooth scaled image using a normalized 3x3 matrix - taking next neighbour
  56                 buffer = CONVOLVER.filter(buffer, null);
  57
  58                 return buffer;
  59         }
  60
  61
  62         /**
  63          * Work out the max size of a thumbnail
  64          * @param inOrigWidth width of original picture
  65          * @param inOrigHeight height of original picture
  66          * @param inMaxWidth max width of thumbnail
  67          * @param inMaxHeight max height of thumbnail
  68          * @return size of thumbnail as Dimension
  69          */
  70         public static Dimension getThumbnailSize(int inOrigWidth, int inOrigHeight, int inMaxWidth, int inMaxHeight)
  71         {
  72                 if (inMaxWidth <= 0 || inMaxHeight <= 0)
  73                 {
  74                         //System.out.println("Can't do it - maxwidth=" + inMaxWidth + ", maxheight=" + inMaxHeight);
  75                         return new Dimension(0,0);
  76                 }
  77                 // work out maximum zoom ratio available so that thumbnail isn't too big
  78                 double xZoom = inMaxWidth * 1.0 / inOrigWidth;
  79                 double yZoom = inMaxHeight * 1.0 / inOrigHeight;
  80                 double zoom = (xZoom > yZoom?yZoom:xZoom);
  81                 // Don't make thumbnail bigger than picture
  82                 if (zoom > 1.0) {return new Dimension(inOrigWidth, inOrigHeight);}
  83                 // calculate new width and height
  84                 return new Dimension ((int) (zoom * inOrigWidth), (int) (zoom * inOrigHeight));
  85         }
  86 }