android - 鱼眼失真

我发现了用Java编写的代码，它将鱼眼效应放在缓冲图像上。是否可以在不同的图像格式（如JPEG或位图）上使用此代码？我尝试用位图替换bufferedimage，而不是使用set/getargb，而是用位图的get/setpixel替换。我刚得到一个黑色位图…我知道这有点难。

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import com.jhlabs.image.InterpolateFilter;

class Filters{
    float xscale;
    float yscale;
    float xshift;
    float yshift;
    int [] s;
    public Filters(){

    }

    public BufferedImage barrel (BufferedImage input, float k){

        float centerX=input.getWidth()/2; //center of distortion
        float centerY=input.getHeight()/2;

        int width = input.getWidth(); //image bounds
        int height = input.getHeight();

        BufferedImage dst = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB); //output pic

          xshift = calc_shift(0,centerX-1,centerX,k);
          float newcenterX = width-centerX;
          float xshift_2 = calc_shift(0,newcenterX-1,newcenterX,k);

          yshift = calc_shift(0,centerY-1,centerY,k);
          float newcenterY = height-centerY;
          float yshift_2 = calc_shift(0,newcenterY-1,newcenterY,k);

          xscale = (width-xshift-xshift_2)/width;
          yscale = (height-yshift-yshift_2)/height;

          for(int j=0;j<dst.getHeight();j++){
              for(int i=0;i<dst.getWidth();i++){
                float x = getRadialX((float)i,(float)j,centerX,centerY,k);
                float y = getRadialY((float)i,(float)j,centerX,centerY,k);
                sampleImage(input,x,y);
                int color = ((s[1]&0x0ff)<<16)|((s[2]&0x0ff)<<8)|(s[3]&0x0ff);
    //            System.out.print(i+" "+j+" \\");

                dst.setRGB(i, j, color);

              }
            }
        return dst;
    }

    void sampleImage(BufferedImage arr, float idx0, float idx1)
    {
        s = new int [4];
      if(idx0<0 || idx1<0 || idx0>(arr.getHeight()-1) || idx1>(arr.getWidth()-1)){
        s[0]=0;
        s[1]=0;
        s[2]=0;
        s[3]=0;
        return;
      }

      float idx0_fl=(float) Math.floor(idx0);
      float idx0_cl=(float) Math.ceil(idx0);
      float idx1_fl=(float) Math.floor(idx1);
      float idx1_cl=(float) Math.ceil(idx1);

      int [] s1 = getARGB(arr,(int)idx0_fl,(int)idx1_fl);
      int [] s2 = getARGB(arr,(int)idx0_fl,(int)idx1_cl);
      int [] s3 = getARGB(arr,(int)idx0_cl,(int)idx1_cl);
      int [] s4 = getARGB(arr,(int)idx0_cl,(int)idx1_fl);

      float x = idx0 - idx0_fl;
      float y = idx1 - idx1_fl;

      s[0]= (int) (s1[0]*(1-x)*(1-y) + s2[0]*(1-x)*y + s3[0]*x*y + s4[0]*x*(1-y));
      s[1]= (int) (s1[1]*(1-x)*(1-y) + s2[1]*(1-x)*y + s3[1]*x*y + s4[1]*x*(1-y));
      s[2]= (int) (s1[2]*(1-x)*(1-y) + s2[2]*(1-x)*y + s3[2]*x*y + s4[2]*x*(1-y));
      s[3]= (int) (s1[3]*(1-x)*(1-y) + s2[3]*(1-x)*y + s3[3]*x*y + s4[3]*x*(1-y));
    }

    int [] getARGB(BufferedImage buf,int x, int y){
        int rgb = buf.getRGB(x, y); // Returns by default ARGB.
        int [] scalar = new int[4];
        scalar[0] = (rgb >>> 24) & 0xFF;
        scalar[1] = (rgb >>> 16) & 0xFF;
        scalar[2] = (rgb >>> 8) & 0xFF;
        scalar[3] = (rgb >>> 0) & 0xFF;
        return scalar;
    }

    float getRadialX(float x,float y,float cx,float cy,float k){
      x = (x*xscale+xshift);
      y = (y*yscale+yshift);
      float res = x+((x-cx)*k*((x-cx)*(x-cx)+(y-cy)*(y-cy)));
      return res;
    }

    float getRadialY(float x,float y,float cx,float cy,float k){
      x = (x*xscale+xshift);
      y = (y*yscale+yshift);
      float res = y+((y-cy)*k*((x-cx)*(x-cx)+(y-cy)*(y-cy)));
      return res;
    }

    float thresh = 1;

    float calc_shift(float x1,float x2,float cx,float k){
      float x3 = (float)(x1+(x2-x1)*0.5);
      float res1 = x1+((x1-cx)*k*((x1-cx)*(x1-cx)));
      float res3 = x3+((x3-cx)*k*((x3-cx)*(x3-cx)));

      if(res1>-thresh && res1 < thresh)
        return x1;
      if(res3<0){
        return calc_shift(x3,x2,cx,k);
      }
      else{
        return calc_shift(x1,x3,cx,k);
      }
    }
}

最佳答案

简短的回答是“是的，这是可能的”。将bufferedimage方法转换为位图方法需要一些时间，但是有大量的在线参考资料可以帮助您解决这个问题。

关于android - 鱼眼失真，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/6214377/