android开发步步为营之81:android图片处理技术之一（截取与缩放）

来源：互联网发布：视频转码软件编辑：程序博客网时间：2024/05/12 23:25
项目需要最近研究了一下图片处理的相关技术，本次分享一下截取与缩放的技术。效果图如下：
代码如下：
package com.figo.study.activity;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Color;import android.os.Bundle;import android.util.Log;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Button;import android.widget.ImageView;import com.figo.study.R;import com.nostra13.universalimageloader.core.decode.BaseImageDecoder;public class BitmapApiActivity extends Activity {    private ImageView ivTest, ivNew;    private Button btnCut, btnScale;    private String tag="BitmapApiActivity";    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_bitmap_api);        ivTest = (ImageView) findViewById(R.id.img_test);        ivNew = (ImageView) findViewById(R.id.img_new);        btnCut = (Button) findViewById(R.id.btn_cut);        btnCut.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                cutImage();            }        });        btnScale = (Button) findViewById(R.id.btn_scale);        //图片缩放        btnScale.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Bitmap bitmapSource = BitmapFactory.decodeResource(getResources(), R.mipmap.ab);                Log.i(tag,"w＝"+bitmapSource.getWidth()+",h="+bitmapSource.getHeight());                //Bitmap bitmapNew = Bitmap.createScaledBitmap(bitmapSource, 200, 200 * bitmapSource.getHeight() / bitmapSource.getWidth(), true);                Bitmap bitmapNew = Bitmap.createScaledBitmap(bitmapSource, 600, 600 * bitmapSource.getHeight() / bitmapSource.getWidth(), true);                ivNew.setImageBitmap(bitmapNew);            }        });    }    //从原图截取蒙版区域不透明部分的图片    private void cutImage() {        Bitmap bitmapSource = BitmapFactory.decodeResource(getResources(), R.mipmap.ab);        int w = bitmapSource.getWidth();        int h = bitmapSource.getHeight();        int[] pixelsSource = new int[w * h];        //获取原图所有像素        bitmapSource.getPixels(pixelsSource, 0, w, 0, 0, w, h);        Bitmap bitmapMask = BitmapFactory.decodeResource(getResources(), R.mipmap.facetype_0);        int w1 = bitmapMask.getWidth();        int h1 = bitmapMask.getHeight();        int[] pixels1 = new int[w1 * h1];        //获取蒙版所有像素        bitmapMask.getPixels(pixels1, 0, w1, 0, 0, w1, h1);        //扣出蒙版区域的原图 蒙版宽高为120*120px,蒙版中心点与原图中心点重合        int total = w1 * h1;        int xNew = (w - w1) / 2;        int yNew = (h - h1) / 2;        //参数为bitmap,x,y,w,h        Bitmap bitmapSourceNew = Bitmap.createBitmap(bitmapSource, xNew, yNew, w1, h1);        int[] sourceNew = new int[total];        bitmapSourceNew.getPixels(sourceNew, 0, w1, 0, 0, w1, h1);        int[] targetNew = new int[total];        for (int i = 0; i < total; i++) {            if (pixels1[i] != Color.TRANSPARENT)                targetNew[i] = sourceNew[i];        }        Bitmap output = Bitmap.createBitmap(targetNew, w1, h1, Bitmap.Config.ARGB_8888);        //显示截取的图片        ivNew.setImageBitmap(output);    }}
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