在Java中将图像大小调整2倍

Question

This is what I have so far, but don't know what to do now? It makes the picture bigger but there is a lot of spaces in the picture. How do you copy pixels to fill in the holes?

public Picture enlarge()
{
 Picture enlarged = new Picture(getWidth() * 2, getHeight() * 2);

for (int x = 0; x < getWidth(); x++)
{
  for (int y = 0; y < getHeight(); y++)
  {
    Pixel orig = getPixel(x,y);
    Pixel enlargedPix = enlarged.getPixel(x*2,y*2);
    Pixel enlargedPix2 = enlarged. getPixel(x,y);
    enlargedPix.setColor(orig.getColor());
    enlargedPix2.setColor(orig.getColor());
  }
}
return enlarged;
}

Answer 1

新图片中存在间隙的原因是，您只需要为每个原始像素设置一次像素，而您必须为原始图像的每个像素设置4个像素（即2x2），因为它是原始图像的两倍。

Answer 2

Well if you enlarge an image times two , and you don't use interpolation . Then a pixel (x,y) of the original image, should be mapped to pixels (2*x,2*y) , (2*x,2*y+1) , (2*x+1,2*y) and (2*x+1,2*y+1) . So the algorithm should be:

Picture enlarged = new Picture(getWidth() * 2, getHeight() * 2);
for (int x = 0; x < getWidth(); x++) {
    for (int y = 0; y < getHeight(); y++) {
        Pixel orig = getPixel(x,y);
        
            
                enlarged.getPixel().setColor(orig.getColor());
            
        
    }
}

Or more generic, with a magnification parameter mag :

Picture enlarged = new Picture(getWidth() * , getHeight() * );
for (int x = 0; x < getWidth(); x++) {
    for (int y = 0; y < getHeight(); y++) {
        Pixel orig = getPixel(x,y);
        for(int x2 = *x; x2 < *x+; x2++) {
            for(int y2 = *y; y2 < *y+; y2++) {
                enlarged.getPixel(x2,y2).setColor(orig.getColor());
            }
        }
    }
}