Messages posted by: Xpectro

Hi,

I'm trying to program a class for a project, that reads a picture as BufferedImage, and resize it using Bilinear Interpolation (Using the mathematical formulas, not the methods included in java). I almost sure that the Bilinear Interpolation part of the method is done, but after many thinking, searching and losing hope, I just can't figure out how to apply the scaling part to the method.

Here's the method:

public static BufferedImage resize(BufferedImage image, int w2, int h2)
{
 
BufferedImage outputImage = new BufferedImage( w2, h2, BufferedImage.TYPE_INT_RGB );
 
// Ratio between original picture and resized picture 
float x_ratio = ((float) (image.getWidth()-1))/w2 ; 
float y_ratio = ((float) (image.getHeight()-1))/h2;
 
// Four pixels a,b,c,d int a, b, c, d, i, j, color; 
float alpha, beta, xabRed, xabGreen, xabBlue, xcdRed, xcdGreen, xcdBlue, xfinalRed, xfinalGreen, xfinalBlue;

for (int x = 0; x < image.getHeight()-1; x++) 
   for( int y = 0; y < image.getWidth()-1; y++){

//Find the color values of the 4 pixels around the desired point to interpolate 
   a = image.getRGB(x, y); 
   b = image.getRGB(x, y + 1); 
   c = image.getRGB(x + 1, y); 
   d = image.getRGB(x + 1, y + 1);

i = (int) (x_ratio * x); 
   j = (int) (y_ratio * y);

alpha = (x_ratio * x) - i; 
   beta = (y_ratio * y) - j;

// a,b represents 2 of the 4 points for interpolation 
   xabRed = alpha * ((b >> 16)&0xff) + (1 - alpha) * ((a >> 16)&0xff); 
   xabGreen = alpha * ((b >> 8)&0xff) + (1 - alpha) * ((a >> 8)&0xff); 
   xabBlue = alpha * (b &0xff) + (1 - alpha) * (a &0xff);

// c,d represents 2 of the 4 points for interpolation 
   xcdRed = alpha * ((d >> 16)&0xff) + (1 - alpha) * ((c >> 16)&0xff); 
   xcdGreen = alpha * ((d >> 8)&0xff) + (1 - alpha) * ((c >> 8)&0xff); 
   xcdBlue = alpha * (d &0xff) + (1 - alpha) * (c &0xff);

// Desired point 
   xfinalRed = beta * xcdRed + (1 - beta) * xabRed; 
   xfinalGreen = beta * xcdGreen + (1 - beta) * xabGreen;      xfinalBlue = beta * xcdBlue + (1 - beta) * xabBlue;

// Prints the RGB values, for bound confirmation    System.out.println((int) xfinalRed + " " + (int) xfinalGreen + " " + (int) xfinalBlue);

// Sets the new color value for the pixel 
   color = new Color((int)xfinalRed, (int)xfinalGreen, (int)xfinalBlue).getRGB();

// Set the pixel 
   outputImage.setRGB(x, y, color); 
}
 return outputImage; 
}

Thanks in advance