Android 图片的特效处理

（转）http://www.cnblogs.com/xingfuzzhd/admin/

1. 图片放缩

// zoom 放缩
public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h) {
    int width = bitmap.getWidth();
    int height = bitmap.getHeight();
    Matrix matrix = new Matrix();

    float scaleWidth = w / (float) width;
    float scaleHeight = h / (float) height;
    matrix.postScale(scaleWidth, scaleHeight);

    Bitmap bitmap2 = Bitmap.createBitmap(bitmap, 0, 0, width, height,
            matrix, true);
    return bitmap2;
}

 

2. 获得圆角图片

// Round Corner Bitmap 获得圆角图片
public static Bitmap getRoundCornerBitmap(Bitmap bitmap, float roundPX /*圆角的半径*/) {
    int width = bitmap.getWidth();
    int height = bitmap.getHeight();

    Bitmap bitmap2 = Bitmap.createBitmap(width, height, Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap2);

    final int color = 0xff424242;
    final Paint paint = new Paint();
    final Rect rect = new Rect(0, 0, width, height);
    final RectF rectF = new RectF(rect);

    paint.setColor(color);
    paint.setAntiAlias(true);
    canvas.drawARGB(0, 0, 0, 0);
    canvas.drawRoundRect(rectF, roundPX, roundPX, paint);

    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
    canvas.drawBitmap(bitmap, rect, rect, paint);

    return bitmap2;
}

 

3. 获得带倒影的图片

// Reflect Bitmap 获得带倒影的图片
public static Bitmap createReflectedBitmap(Bitmap bitmap) {
    //倒影和图片本身的间距
    final int reflectedGap = 4;
    int width = bitmap.getWidth();
    int height = bitmap.getHeight();

    Matrix matrix = new Matrix();
    matrix.preScale(1, -1);

    Bitmap reflectedImage = Bitmap.createBitmap(bitmap, 0, height / 2,
            width, height / 2, matrix, false);
    Bitmap reflectedBitmap = Bitmap.createBitmap(width,
            (height + height / 2), Config.ARGB_8888);

    Canvas canvas = new Canvas(reflectedBitmap);
    canvas.drawBitmap(bitmap, 0, 0, null);
    Paint defaultPaint = new Paint();
    canvas.drawRect(0, height, width, height + reflectedGap, defaultPaint);
    canvas.drawBitmap(reflectedImage, 0, height + reflectedGap, null);

    Paint paint = new Paint();
    LinearGradient shader = new LinearGradient(0, bitmap.getHeight(), 0,
            reflectedBitmap.getHeight() + reflectedGap, 0x70ffffff,
            0x00ffffff, TileMode.CLAMP);
    paint.setShader(shader);
    paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
    canvas.drawRect(0, height, width, reflectedBitmap.getHeight()
            + reflectedGap, paint);

    return reflectedBitmap;
}