Android中几种图像特效处理的集锦

 

给大家分享的是Android图像特效处理的小技巧，比如圆角、倒影、还有就是图片缩放、Drawable转化为Bitmap、Bitmap转化为Drawable等等。

废话少说，直接讲解今天的实例，本例主要是先获取壁纸(getWallpaper()),然后对当前壁纸的一些特效处理。大家按步骤一步一步来：

第一步：新建一个Android工程命名为ImageDemo,工程结构如下：

第二步：新建一个.java文件，命名为ImageUtil.java,在里面定义一些图片处理方法，代码如下：

 

package com.android.tutor;
 
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.Shader.TileMode;
import android.graphics.drawable.Drawable;
 
public class ImageUtil {
 
    // 放大缩小图片
    public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h) {
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        Matrix matrix = new Matrix();
        float scaleWidht = ((float) w / width);
        float scaleHeight = ((float) h / height);
        matrix.postScale(scaleWidht, scaleHeight);
        Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height,
                matrix, true);
        return newbmp;
    }
 
    // 将Drawable转化为Bitmap
    public static Bitmap drawableToBitmap(Drawable drawable) {
        int width = drawable.getIntrinsicWidth();
        int height = drawable.getIntrinsicHeight();
        Bitmap bitmap = Bitmap.createBitmap(width, height, drawable
                .getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                : Bitmap.Config.RGB_565);
        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, width, height);
        drawable.draw(canvas);
        return bitmap;
 
    }
 
    // 获得圆角图片的方法
    public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, float roundPx) {
 
        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);
 
        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
        final RectF rectF = new RectF(rect);
 
        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
 
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);
 
        return output;
    }
 
    // 获得带倒影的图片方法
    public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap) {
        final int reflectionGap = 4;
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
 
        Matrix matrix = new Matrix();
        matrix.preScale(1, -1);
 
        Bitmap reflectionImage = Bitmap.createBitmap(bitmap, 0, height / 2,
                width, height / 2, matrix, false);
 
        Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
                (height + height / 2), Config.ARGB_8888);
 
        Canvas canvas = new Canvas(bitmapWithReflection);
        canvas.drawBitmap(bitmap, 0, 0, null);
        Paint deafalutPaint = new Paint();
        canvas.drawRect(0, height, width, height + reflectionGap, deafalutPaint);
 
        canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
 
        Paint paint = new Paint();
        LinearGradient shader = new LinearGradient(0, bitmap.getHeight(), 0,
                bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff,
                0x00ffffff, TileMode.CLAMP);
        paint.setShader(shader);
        // Set the Transfer mode to be porter duff and destination in
        paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
        // Draw a rectangle using the paint with our linear gradient
        canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
                + reflectionGap, paint);
 
        return bitmapWithReflection;
    }
 
}

 第三步：修改main.xml布局文件，主要放了两个ImageView控件，代码如下：

 

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <ImageView
        android:id="@+id/image01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10px"
        />
    <ImageView
        android:id="@+id/image02"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="10px"
    />
</LinearLayout>

 第四步：修改主核心程序，ImageDemo.java,代码如下：

 

 

package com.android.tutor;
 
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.ImageView;
 
public class Imagedemo extends Activity {
     
    private ImageView mImageView01, mImageView02;
 
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        setupViews();
    }
 
    private void setupViews() {
         
        mImageView01 = (ImageView) findViewById(R.id.image01);
        mImageView02 = (ImageView) findViewById(R.id.image02);
 
        // 获取壁纸返回值是Drawable
        Drawable drawable = getWallpaper();
        // 将Drawable转化为Bitmap
        Bitmap bitmap = ImageUtil.drawableToBitmap(drawable);
        // 缩放图片
        Bitmap zoomBitmap = ImageUtil.zoomBitmap(bitmap, 100, 100);
        // 获取圆角图片
        Bitmap roundBitmap = ImageUtil
                .getRoundedCornerBitmap(zoomBitmap, 10.0f);
        // 获取倒影图片
        Bitmap reflectBitmap = ImageUtil
                .createReflectionImageWithOrigin(zoomBitmap);
        // 这里可以让Bitmap再转化为Drawable
        // Drawable roundDrawable = new BitmapDrawable(roundBitmap);
        // Drawable reflectDrawable = new BitmapDrawable(reflectBitmap);
        // mImageView01.setBackgroundDrawable(roundDrawable);
        // mImageView02.setBackgroundDrawable(reflectDrawable);
 
        mImageView01.setImageBitmap(roundBitmap);
        mImageView02.setImageBitmap(reflectBitmap);
    }
 
}

 第五步：运行上述工程，查看效果如下：