android处理图片工具

package com.wireme.activity;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Paint;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Bitmap.Config;
import android.graphics.PorterDuff.Mode;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;

/**
* 处理图片的工具类.
*/
public class imageTool {
    public static final int LEFT = 0;
    public static final int RIGHT = 1;
    public static final int TOP = 3;
    public static final int BOTTOM = 4;

    /** */
    /**
     * 图片去色,返回灰度图片
     *
     * @param bmpOriginal
     *            传入的图片
     * @return 去色后的图片
     */
    public static Bitmap toGrayscale(Bitmap bmpOriginal) {
        int width, height;
        height = bmpOriginal.getHeight();
        width = bmpOriginal.getWidth();
        Bitmap bmpGrayscale = Bitmap.createBitmap(width, height,
                Bitmap.Config.RGB_565);
        Canvas c = new Canvas(bmpGrayscale);
        Paint paint = new Paint();
        ColorMatrix cm = new ColorMatrix();
        cm.setSaturation(0);
        ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
        paint.setColorFilter(f);
        c.drawBitmap(bmpOriginal, 0, 0, paint);
        return bmpGrayscale;
    }

    /** */
    /**
     * 去色同时加圆角
     *
     * @param bmpOriginal
     *            原图
     * @param pixels
     *            圆角弧度
     * @return 修改后的图片
     */
    public static Bitmap toGrayscale(Bitmap bmpOriginal, int pixels) {
        return toRoundCorner(toGrayscale(bmpOriginal), pixels);
    }

    /** */
    /**
     * 把图片变成圆角
     *
     * @param bitmap
     *            需要修改的图片
     * @param pixels
     *            圆角的弧度
     * @return 圆角图片
     */
    public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) {
        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);
        final float roundPx = pixels;
        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;
    }

    /** */
    /**
     * 使圆角功能支持BitampDrawable
     *
     * @param bitmapDrawable
     * @param pixels
     * @return
     */
    public static BitmapDrawable toRoundCorner(BitmapDrawable bitmapDrawable,
            int pixels) {
        Bitmap bitmap = bitmapDrawable.getBitmap();
        bitmapDrawable = new BitmapDrawable(toRoundCorner(bitmap, pixels));
        return bitmapDrawable;
    }

    /**
     * 读取路径中的图片，然后将其转化为缩放后的bitmap
     *
     * @param path
     */
    public static void saveBefore(String path) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        // 获取这个图片的宽和高
        Bitmap bitmap = BitmapFactory.decodeFile(path, options); // 此时返回bm为空
        options.inJustDecodeBounds = false;
        // 计算缩放比
        int be = (int) (options.outHeight / (float) 200);
        if (be <= 0)
            be = 1;
        options.inSampleSize = 2; // 图片长宽各缩小二分之一
        // 重新读入图片，注意这次要把options.inJustDecodeBounds 设为 false哦
        bitmap = BitmapFactory.decodeFile(path, options);
        int w = bitmap.getWidth();
        int h = bitmap.getHeight();
        System.out.println(w + &q

补充：移动开发 , Android ,