BitmapUtil.java

package com.sjl.yuehu.util;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.Build;
import android.renderscript.Allocation;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.view.View;

import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Created by simon on 2016/4/30
 */
public class BitmapUtil {

    /**
     * 通过uri获取图片并进行压缩
     *
     * @param uri
     */
    public static Bitmap getBitmapFormUri(Context context, Uri uri) throws IOException {
        InputStream input = context.getContentResolver().openInputStream(uri);
        BitmapFactory.Options onlyBoundsOptions = new BitmapFactory.Options();
        onlyBoundsOptions.inJustDecodeBounds = true;
        onlyBoundsOptions.inDither = true;//optional
        onlyBoundsOptions.inPreferredConfig = Bitmap.Config.RGB_565;//optional
        BitmapFactory.decodeStream(input, null, onlyBoundsOptions);
        input.close();
        int originalWidth = onlyBoundsOptions.outWidth;
        int originalHeight = onlyBoundsOptions.outHeight;
        if ((originalWidth == -1) || (originalHeight == -1))
            return null;
        //图片分辨率以480x800为标准
        float hh = 800f;//这里设置高度为800f
        float ww = 480f;//这里设置宽度为480f
        //缩放比。由于是固定比例缩放，只用高或者宽其中一个数据进行计算即可
        int be = 1;//be=1表示不缩放
        if (originalWidth > originalHeight && originalWidth > ww) {//如果宽度大的话根据宽度固定大小缩放
            be = (int) (originalWidth / ww);
        } else if (originalWidth < originalHeight && originalHeight > hh) {//如果高度高的话根据宽度固定大小缩放
            be = (int) (originalHeight / hh);
        }
        if (be <= 0)
            be = 1;
        //比例压缩
        BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
        bitmapOptions.inSampleSize = be;//设置缩放比例
        bitmapOptions.inDither = true;//optional
        bitmapOptions.inPreferredConfig = Bitmap.Config.ARGB_8888;//optional
        input = context.getContentResolver().openInputStream(uri);
        Bitmap bitmap = BitmapFactory.decodeStream(input, null, bitmapOptions);
        input.close();

        return compressImage(bitmap);//再进行质量压缩
    }

    /**
     * 质量压缩方法
     *
     * @param image
     * @return
     */
    public static Bitmap compressImage(Bitmap image) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        image.compress(Bitmap.CompressFormat.JPEG, 100, baos);//质量压缩方法，这里100表示不压缩，把压缩后的数据存放到baos中
        int options = 100;
        while (baos.toByteArray().length / 1024 > 100) {  //循环判断如果压缩后图片是否大于100kb,大于继续压缩
            baos.reset();//重置baos即清空baos
            //第一个参数 ：图片格式 ，第二个参数： 图片质量，100为最高，0为最差  ，第三个参数：保存压缩后的数据的流
            image.compress(Bitmap.CompressFormat.JPEG, options, baos);//这里压缩options%，把压缩后的数据存放到baos中
            options -= 10;//每次都减少10
        }
        ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());//把压缩后的数据baos存放到ByteArrayInputStream中
        Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, null);//把ByteArrayInputStream数据生成图片
        return bitmap;
    }

    /**
     * 保存到指定路径
     *
     * @param bitmap
     * @param path
     */
    public static void saveBitmap(Bitmap bitmap, File path) {
        if (bitmap == null) return;

        FileOutputStream fout = null;
        BufferedOutputStream bout = null;
        try {
            fout = new FileOutputStream(path);
            bout = new BufferedOutputStream(fout, 1024 * 6);
        } catch (Exception e) {
            e.printStackTrace();
        }
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bout);
        try {
            bout.flush();
            bout.close();
            fout.close();
//            ToastUtil.showLong("图片保存成功");
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    public static byte[] uri2Byte(Context context, Uri uri) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            InputStream is = context.getContentResolver().openInputStream(uri);
            int len;
            byte[] buffer = new byte[1024];
            while ((len = is.read(buffer)) != -1) {
                baos.write(buffer, 0, len);
            }
            is.close();
            baos.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return baos.toByteArray();
    }

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
    public static void blur(Bitmap bkg, View view, float radius) {
        int width = view.getMeasuredWidth();
        int height = view.getMeasuredHeight();

        Bitmap overlay = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(overlay);
        canvas.drawBitmap(bkg, null, new RectF(-view.getLeft(), -view.getTop(), width, height), null);
        RenderScript rs = RenderScript.create(view.getContext());
        Allocation overlayAlloc = Allocation.createFromBitmap(rs, overlay);
        ScriptIntrinsicBlur blur = ScriptIntrinsicBlur.create(rs, overlayAlloc.getElement());
        blur.setInput(overlayAlloc);
        blur.setRadius(radius);
        blur.forEach(overlayAlloc);
        overlayAlloc.copyTo(overlay);
        view.setBackground(new BitmapDrawable(view.getResources(), overlay));
        rs.destroy();
    }
}