fisheye distortion

Question

I've found the code below written in java that places a fisheye effect on a buffered image. Is it possible to use this code on a different image format eg jpeg or bitmap? I've tried replacing the bufferedImage with bitmap and instead of using set/getARGB i've replaced with bitmap's get/setPixel. i just get a black bitmap.... i know was a bit of a long-shot:).

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);
      }
    }
}

It should work - you'll just have to put more work into troubleshooting it. — Haphazard, Jun 02 '11 at 12:50
@haphazard hi, i've been looking for ways around this problem, including opencv, opengl, jjil, porting etc. All are bit much for my ability at the moment. BufferedImage is not supported on Android and hence my above question. i was just wondering how to alter this code so that it manipulates an image of a diffent format. thanks — turtleboy, Jun 02 '11 at 13:57
Indeed, and that is far more code than I can help you fix up today. As you mentioned, replace the BufferedImage with a Bitmap and start cleaning up all the errors. There are plenty of resources online on what each function in BufferedImage translates to in Bitmap (I've had to do it before!) — Haphazard, Jun 02 '11 at 14:13
@haphazard oh ok...well thats encouraging then. The feedback so far from various developers is there's no work around or replacement for the bufferedimage and so can't use this code. so you honestly think this is "do-able" with regards to finding the corresponding methods in the bitmap class? — turtleboy, Jun 02 '11 at 14:28
Yup. I have done some mildly complex data manipulation on Bitmaps which was ported over from BufferedImage. they can do the same things, you just have to massage it into shape. — Haphazard, Jun 02 '11 at 14:30
@haphazard ok cool, so it's just a case of matching up the methods in the respective APIs? Thanks for your advice — turtleboy, Jun 02 '11 at 15:01
I've put in an answer so you can close this question off, if you'd like. — Haphazard, Jun 02 '11 at 15:12

score 5 · Answer 1 · answered Jun 04 '11 at 17:01

it works fine thanks. i just matched up the setARGB() methods from bufferedImage with setPixel() from the bitmap class and voila! thanks again

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

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.util.Log;

import com.jhlabs.image.InterpolateFilter;

class Filters{
    float xscale;
    float yscale;
    float xshift;
    float yshift;
    int [] s;
    private String TAG = "Filters";
    public Filters(){

        Log.e(TAG, "***********inside constructor");
    }

    public Bitmap barrel (Bitmap input, float k){
        Log.e(TAG, "***********inside barrel method ");
        float centerX=input.getWidth()/2; //center of distortion
        float centerY=input.getHeight()/2;

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

        Bitmap dst = Bitmap.createBitmap(width, height,input.getConfig() ); //output pic
        Log.e(TAG, "***********dst bitmap created ");
          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;
          Log.e(TAG, "***********about to loop through bm");
          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.setPixel(i, j, color);

              }
            }
        return dst;
    }

    void sampleImage(Bitmap 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(Bitmap buf,int x, int y){
        int rgb = buf.getPixel(y, x); // 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);
      }
    }
}

i run your code,very cool,but i have a question:your result bitmap is rotated 90 from the original bitmap.how to only fisheye distortion not rotate? — pengwang, Sep 26 '11 at 06:14
@pengwang hi, in the barrel method you call getradial(). Switch the args ì and j so they are j and ì. Hth. What you developing? — turtleboy, Oct 05 '11 at 09:11
hi @turtleboy can u plz tal me value of k in barrel(Bitmap input, float k) . — Youddh, Nov 29 '12 at 07:35
@Youddh Hi, i'll have a look when i get back tonight, but going from memory it is something like 0.000015. I'll check and get back to you. — turtleboy, Nov 29 '12 at 14:14
@turtleboy i try it but i don't no y the image is not displayed after apply barrel (Bitmap input, float k) method . — Youddh, Nov 30 '12 at 05:48
@Youddh Ah it has a bug in the code. It runs fine on Android 2.1, this was the api i originally wrote it for. i bought an HTC one x recently and the distortion doesn't show on Android 4.x. I haven't had time to test why. try it on i lower android first and then maybe test why it not work on 4.x. i'd like to know myself;) — turtleboy, Nov 30 '12 at 12:07
@Youddh Also have a look at this post. I re-coded the code you have to use paralellisation. It divides the bitmap up between how many available processors there are at runtime. HTH http://stackoverflow.com/questions/1927145/how-to-simulate-fisheye-lens-effect-by-opencv — turtleboy, Nov 30 '12 at 12:19

score 1 · Accepted Answer · answered Jun 02 '11 at 15:11

1

The short answer is "yes, it is possible". It will take some time for you to translate the BufferedImage methods to the Bitmap methods but there are plenty of good references online that will be able to help you out.

answered Jun 02 '11 at 15:11

Haphazard

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