Android 縮小圖像陣列

 

package qas_tool;

import android.graphics.Bitmap;

public class Resize_buffer {

    private  int []resize_buffer;
    private  int origin_w;
    private  int origin_h;
    private  int resize_w;
    private  int resize_h;
    private  int div_h;
    private  float scale_x;
    private  float scale_y;
    private  int neast_x;
    private  int neast_y;

    public  Resize_buffer(int orgin_w,int origin_h,int new_w,int new_h){
        resize_buffer=new int[new_w*new_h];

        this.origin_w=orgin_w;
        this.origin_h=origin_h;
        this.resize_w=new_w;
        this.resize_h=new_h;

        resize_buffer=new int[new_w*new_h];
        scale_x=new_w/(float)orgin_w;
        scale_y=new_h/(float)origin_h;
        div_h=resize_h/4;

    }
    public  int[]buffer; //point buffer

    private  Thread thread1,thread2,thread3;
    public Bitmap resize_Bitmap(){

        thread1=new Thread(new Runnable() {
            @Override
            public void run() {
                process_resize(0,0,resize_w,div_h);

            }
        });

        thread2=new Thread(new Runnable() {
            @Override
            public void run() {
                process_resize(0,div_h,resize_w,2*div_h);

            }
        });

        thread3=new Thread(new Runnable() {
            @Override
            public void run() {
                process_resize(0,2*div_h,resize_w,3*div_h);

            }
        });

        thread1.start();
        thread2.start();
        thread3.start();
        process_resize(0,3*div_h,resize_w,resize_h);
        while (thread1.isAlive() || thread2.isAlive() || thread3.isAlive());

        return Bitmap.createBitmap(resize_buffer,resize_w,resize_h, Bitmap.Config.ARGB_8888);
    }
    private  void process_resize(int left,int top,int right,int bottom){
        for(int j=top;j<bottom;j++) {
            for (int i = left; i < right; i++) {
                neast_x=Math.round(i/scale_x);
                neast_y=Math.round(j/scale_y);
                resize_buffer[i+j*resize_w]=buffer[neast_x+neast_y*origin_w];
            }
        }
    }


}