Android 图像处理（类型转换，比例缩放，倒影，圆角）（转）

[quote]http://www.cnblogs.com/zhengtao/articles/1930802.htm[/quote]

//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;
}