图片处理工具类（缩放，圆角，倒影）

[android]代码库

package com.demo;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader.TileMode;

/**
 * 图片处理工具类（缩放，圆角，倒影）
 * 
 */
public class ImageUtils {
	/**
	 * 图片缩放
	 * 
	 * @param pBitmap
	 * @param pW
	 * @param pH
	 * @return
	 */
	public static Bitmap zoomBitmap(Bitmap pBitmap, int pW, int pH) {

		int _width = pBitmap.getWidth();// 获取原图的宽
		int _heigth = pBitmap.getHeight();// 获取原图的高

		// 获取缩放比
		float _ScaleW = (float) pW / _width;
		float _ScaleH = (float) pH / _heigth;

		Matrix _Matrix = new Matrix();// 创建Matrix矩阵对象

		_Matrix.setScale(_ScaleW, _ScaleH);// 设置宽高的缩放比

		return Bitmap.createBitmap(pBitmap, 0, 0, _width, _heigth, _Matrix,
				true);// 对截原图的0，0坐标到_width，_heigth的图片进行_Matrix处理
	}

	/**
	 * 图片圆角
	 * 
	 * @param pBitmap
	 * @param pRoundpx
	 * @return
	 */
	public static Bitmap RoundedCornerBitmap(Bitmap pBitmap, float pRoundpx) {

		Bitmap _NewBitmap = Bitmap.createBitmap(pBitmap.getWidth(),
				pBitmap.getHeight(), Config.ARGB_8888); // 创建图片画布大小
		Canvas _Canvas = new Canvas(_NewBitmap); // 创建画布
		_Canvas.drawARGB(0, 0, 0, 0); // 设置画布透明
		Paint _Paint = new Paint(); // 创建画笔
		_Paint.setAntiAlias(true); // 抗锯齿
		_Paint.setColor(0xff000000);// 画笔颜色透明

		// 画与原图片大小一致的圆角矩形
		Rect _Rect = new Rect(0, 0, pBitmap.getWidth(), pBitmap.getHeight());
		RectF _RectF = new RectF(_Rect);
		_Canvas.drawRoundRect(_RectF, pRoundpx, pRoundpx, _Paint);

		_Paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));// 设置下面张图片与上面张图片的交互模式
		_Canvas.drawBitmap(pBitmap, _Rect, _Rect, _Paint);// 画原图到画布
		return _NewBitmap;
	}

	/**
	 * 图片倒影
	 * 
	 * @param pBitmap
	 * @return
	 */
	public static Bitmap ReflectionImageWithOrigin(Bitmap pBitmap) {
		// 创建等宽，高+高/5的画布
		Bitmap _NewBitmap = Bitmap
				.createBitmap(pBitmap.getWidth(),
						pBitmap.getHeight() + pBitmap.getHeight() / 5,
						Config.ARGB_8888);
		Canvas _Canvas = new Canvas(_NewBitmap);

		_Canvas.drawBitmap(pBitmap, 0, 0, null);// 画上原图

		// 原图翻转，
		Matrix _Matrix = new Matrix();
		_Matrix.preScale(1, -1);
		Bitmap _Bitmap = Bitmap.createBitmap(pBitmap, 0, 0, pBitmap.getWidth(),
				pBitmap.getHeight(), _Matrix, true);

		// 在剩余画布上画上翻转图
		_Canvas.drawBitmap(_Bitmap, 0, pBitmap.getHeight(), null);
		Paint _Paint = new Paint();

		// 实现图片的渐变效果
		LinearGradient shader = new LinearGradient(0, pBitmap.getHeight(), 0,
				_NewBitmap.getHeight(), 0x70ffffff, 0x00ffffff, TileMode.CLAMP);
		_Paint.setShader(shader);
		_Paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
		_Canvas.drawRect(0, pBitmap.getHeight(), pBitmap.getWidth(),
				_NewBitmap.getHeight(), _Paint);
		return _NewBitmap;
	}

}