Android图片缩放、圆角处理以及倒影特效代码

public class ImageUtil {

//缩放图片
public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h)
{
int width = bitmap.getWidth();
int height = bitmap.getHeight();
Matrix matrix = new Matrix();
float scaleWidth = ((float)w/width);
float scaleHeight = ((float)h/height);
matrix.postScale(scaleHeight, scaleHeight);
Bitmap newBmp = Bitmap.createBitmap(bitmap, 0, 0, width, height,matrix,true);
return newBmp;
}

//Drawable 转换为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;
}

//圆角处理
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;
}

//倒影图片处理
public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap)
{
final int reflectionGap = 4; //magic number?
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 destionation 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;
}
}