Android 图片特效处理的方法实例

// 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; 
} 

// 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; 
} 

// 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; 
}