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

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);

}

}