android 处理图片工具

转自：http://terryblog.blog.51cto.com/1764499/791516

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 + " " + h);
        // savePNG_After(bitmap,path);
        saveJPGE_After(bitmap, path);
    }

    /**
     * 保存图片为PNG
     *
     * @param bitmap
     * @param name
     */
    public static void savePNG_After(Bitmap bitmap, String name) {
        File file = new File(name);
        try {
            FileOutputStream out = new FileOutputStream(file);
            if (bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)) {
                out.flush();
                out.close();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 保存图片为JPEG
     *
     * @param bitmap
     * @param path
     */
    public static void saveJPGE_After(Bitmap bitmap, String path) {
        File file = new File(path);
        try {
            FileOutputStream out = new FileOutputStream(file);
            if (bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out)) {
                out.flush();
                out.close();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 水印
     *
     * @param bitmap
     * @return
     */
    public static Bitmap createBitmapForWatermark(Bitmap src, Bitmap watermark) {
        if (src == null) {
            return null;
        }
        int w = src.getWidth();
        int h = src.getHeight();
        int ww = watermark.getWidth();
        int wh = watermark.getHeight();
        // create the new blank bitmap
        Bitmap newb = Bitmap.createBitmap(w, h, Config.ARGB_8888);// 创建一个新的和SRC长度宽度一样的位图
        Canvas cv = new Canvas(newb);
        // draw src into
        cv.drawBitmap(src, 0, 0, null);// 在 0，0坐标开始画入src
        // draw watermark into
        cv.drawBitmap(watermark, w - ww + 5, h - wh + 5, null);// 在src的右下角画入水印
        // save all clip
        cv.save(Canvas.ALL_SAVE_FLAG);// 保存
        // store
        cv.restore();// 存储
        return newb;
    }

    /**
     * 图片合成
     *
     * @return
     */
    public static Bitmap potoMix(int direction, Bitmap... bitmaps) {
        if (bitmaps.length <= 0) {
            return null;
        }
        if (bitmaps.length == 1) {
            return bitmaps[0];
        }
        Bitmap newBitmap = bitmaps[0];
        // newBitmap = createBitmapForFotoMix(bitmaps[0],bitmaps[1],direction);
        for (int i = 1; i < bitmaps.length; i++) {
            newBitmap = createBitmapForFotoMix(newBitmap, bitmaps[i], direction);
        }
        return newBitmap;
    }

    private static Bitmap createBitmapForFotoMix(Bitmap first, Bitmap second,
            int direction) {
        if (first == null) {
            return null;
        }
        if (second == null) {
            return first;
        }
        int fw = first.getWidth();
        int fh = first.getHeight();
        int sw = second.getWidth();
        int sh = second.getHeight();
        Bitmap newBitmap = null;
        if (direction == LEFT) {
            newBitmap = Bitmap.createBitmap(fw + sw, fh > sh ? fh : sh,
                    Config.ARGB_8888);
            Canvas canvas = new Canvas(newBitmap);
            canvas.drawBitmap(first, sw, 0, null);
            canvas.drawBitmap(second, 0, 0, null);
        } else if (direction == RIGHT) {
            newBitmap = Bitmap.createBitmap(fw + sw, fh > sh ? fh : sh,
                    Config.ARGB_8888);
            Canvas canvas = new Canvas(newBitmap);
            canvas.drawBitmap(first, 0, 0, null);
            canvas.drawBitmap(second, fw, 0, null);
        } else if (direction == TOP) {
            newBitmap = Bitmap.createBitmap(sw > fw ? sw : fw, fh + sh,
                    Config.ARGB_8888);
            Canvas canvas = new Canvas(newBitmap);
            canvas.drawBitmap(first, 0, sh, null);
            canvas.drawBitmap(second, 0, 0, null);
        } else if (direction == BOTTOM) {
            newBitmap = Bitmap.createBitmap(sw > fw ? sw : fw, fh + sh,
                    Config.ARGB_8888);
            Canvas canvas = new Canvas(newBitmap);
            canvas.drawBitmap(first, 0, 0, null);
            canvas.drawBitmap(second, 0, fh, null);
        }
        return newBitmap;
    }

    /**
     * 将Bitmap转换成指定大小
     *
     * @param bitmap
     * @param width
     * @param height
     * @return
     */
    public static Bitmap createBitmapBySize(Bitmap bitmap, int width, int height) {
        return Bitmap.createScaledBitmap(bitmap, width, height, true);
    }

    /**
     * Drawable 转 Bitmap
     *
     * @param drawable
     * @return
     */
    public static Bitmap drawableToBitmapByBD(Drawable drawable) {
        BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
        return bitmapDrawable.getBitmap();
    }

    /**
     * Bitmap 转 Drawable
     *
     * @param bitmap
     * @return
     */
    public static Drawable bitmapToDrawableByBD(Bitmap bitmap) {
        Drawable drawable = new BitmapDrawable(bitmap);
        return drawable;
    }

    /**
     * byte[] 转 bitmap
     *
     * @param b
     * @return
     */
    public static Bitmap bytesToBimap(byte[] b) {
        if (b.length != 0) {
            return BitmapFactory.decodeByteArray(b, 0, b.length);
        } else {
            return null;
        }
    }

    /**
     * bitmap 转 byte[]
     *
     * @param bm
     * @return
     */
    public static byte[] bitmapToBytes(Bitmap bm) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
        return baos.toByteArray();
    }
}