Jak zmienić rozmiar buforowanego obrazu n grafiki 2d w java?

Question

int width = 175; 
Graphics2D gb = (Graphics2D) g; 

     bufferedimage = (BufferedImage) createImage(width, width); 

     Graphics2D graphics = bufferedimage.createGraphics(); 
     graphics.setColor(/*this.getBackground()*/Color.red); 
     graphics.fillRect(0, 0, width, width); 

Witam mam zbuforowane z dużym rozmiarem ... muszę zmienić rozmiar obrazu bufora ... plz możesz mi pomóc?

Answer 1

public BufferedImage scaleImage(BufferedImage img, int width, int height, 
     Color background) { 
    int imgWidth = img.getWidth(); 
    int imgHeight = img.getHeight(); 
    if (imgWidth*height < imgHeight*width) { 
     width = imgWidth*height/imgHeight; 
    } else { 
     height = imgHeight*width/imgWidth; 
    } 
    BufferedImage newImage = new BufferedImage(width, height, 
      BufferedImage.TYPE_INT_RGB); 
    Graphics2D g = newImage.createGraphics(); 
    try { 
     g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, 
       RenderingHints.VALUE_INTERPOLATION_BICUBIC); 
     g.setBackground(background); 
     g.clearRect(0, 0, width, height); 
     g.drawImage(img, 0, 0, width, height, null); 
    } finally { 
     g.dispose(); 
    } 
    return newImage; 
} 

UPDATE: różne algorytmy

import java.awt.Graphics2D; 
import java.awt.Image; 
import java.awt.RenderingHints; 
import java.awt.image.BufferedImage; 

public enum Resizer { 
    NEAREST_NEIGHBOR { 
     @Override 
     public BufferedImage resize(BufferedImage source, 
       int width, int height) { 
      return commonResize(source, width, height, 
        RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR); 
     } 
    }, 
    BILINEAR { 
     @Override 
     public BufferedImage resize(BufferedImage source, 
       int width, int height) { 
      return commonResize(source, width, height, 
        RenderingHints.VALUE_INTERPOLATION_BILINEAR); 
     } 
    }, 
    BICUBIC { 
     @Override 
     public BufferedImage resize(BufferedImage source, 
       int width, int height) { 
      return commonResize(source, width, height, 
        RenderingHints.VALUE_INTERPOLATION_BICUBIC); 
     } 
    }, 
    PROGRESSIVE_BILINEAR { 
     @Override 
     public BufferedImage resize(BufferedImage source, 
       int width, int height) { 
      return progressiveResize(source, width, height, 
        RenderingHints.VALUE_INTERPOLATION_BILINEAR); 
     } 
    }, 
    PROGRESSIVE_BICUBIC { 
     @Override 
     public BufferedImage resize(BufferedImage source, 
       int width, int height) { 
      return progressiveResize(source, width, height, 
        RenderingHints.VALUE_INTERPOLATION_BICUBIC); 
     } 
    }, 
    AVERAGE { 
     @Override 
     public BufferedImage resize(BufferedImage source, 
       int width, int height) { 
      Image img2 = source.getScaledInstance(width, height, 
        Image.SCALE_AREA_AVERAGING); 
      BufferedImage img = new BufferedImage(width, height, 
        source.getType()); 
      Graphics2D g = img.createGraphics(); 
      try { 
       g.drawImage(img2, 0, 0, width, height, null); 
      } finally { 
       g.dispose(); 
      } 
      return img; 
     } 
    }; 

    public abstract BufferedImage resize(BufferedImage source, 
      int width, int height); 

    private static BufferedImage progressiveResize(BufferedImage source, 
      int width, int height, Object hint) { 
     int w = Math.max(source.getWidth()/2, width); 
     int h = Math.max(source.getHeight()/2, height); 
     BufferedImage img = commonResize(source, w, h, hint); 
     while (w != width || h != height) { 
      BufferedImage prev = img; 
      w = Math.max(w/2, width); 
      h = Math.max(h/2, height); 
      img = commonResize(prev, w, h, hint); 
      prev.flush(); 
     } 
     return img; 
    } 

    private static BufferedImage commonResize(BufferedImage source, 
      int width, int height, Object hint) { 
     BufferedImage img = new BufferedImage(width, height, 
       source.getType()); 
     Graphics2D g = img.createGraphics(); 
     try { 
      g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, hint); 
      g.drawImage(source, 0, 0, width, height, null); 
     } finally { 
      g.dispose(); 
     } 
     return img; 
    } 
};