昨天看了下RenderScript的官方文檔，發(fā)現(xiàn)RenderScript這廝有點(diǎn)牛逼。無(wú)意中發(fā)現(xiàn)ScriptIntrinsic這個(gè)抽象類，有些很有用的子類。其中有個(gè)子類叫ScriptIntrinsicBlur類，大致就是將圖片實(shí)現(xiàn)高斯模糊。
ScriptIntrinsic的申明：
ScriptIntrinsicBlur類的申明：
加上結(jié)合著看了下SDK中的samples,自己寫(xiě)了個(gè)高斯模糊。
（ sample的具體位置為：
SDK目錄/samples/android-19/renderscript/RenderScriptIntrinsic/RenderScriptIntrinsicSample/
）。
先上圖。效果如下：
【注意！！ 開(kāi)始之前，我們需要導(dǎo)入需要的支持包。
支持包的具體路徑為： sdk目錄/buildtools/任意一個(gè)版本號(hào)/renderscript/lib/renderscript-v8.jar
另外：為了防止出現(xiàn)有的機(jī)型兼容問(wèn)題，最好將renderscript-v8.jar同目錄下的packaged目錄下的所有庫(kù)也一并拷貝到lib文件夾下】
例如：
好了。開(kāi)始寫(xiě)代碼。。
1、先申明常用成員變量。
private SeekBar blurSeekBar;//拖動(dòng)條private ImageView img_blur;//顯示模糊后bitmap的ImageView//原bitmap和高斯模糊后的bitmapprivate Bitmap bitmap_original, bitmap_blur;//高斯模糊處理的AsyncTaskprivate RenderScriptTask mLatestTask = null;//RenderScript 對(duì)象（Google的高性能并行計(jì)算類，他可以利用設(shè)備的GPU/CPU等計(jì)算資源）private RenderScript mRS;//下面是兩個(gè)RenderScript的傳入?yún)?shù)對(duì)象private Allocation mInAllocation;private Allocation mOutAllocation;//高斯模糊處理實(shí)例private ScriptIntrinsicBlur mScriptBlur;
2、加載兩份bitmap，并初始化高斯模糊相關(guān)的對(duì)象。
@Overrideprotected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); blurSeekBar = (SeekBar) findViewById(R.id.aty_main_seekBar); img_blur = (ImageView) findViewById(R.id.aty_main_img_blur); bitmap_original = loadBitmap(R.drawable.meet_entry_guide_3); // 復(fù)制一份 bitmap_blur = Bitmap.createBitmap(bitmap_original.getWidth(), bitmap_original.getHeight(), bitmap_original.getConfig()); createBlureScript(); setSeekBarListening();//為SeekBar設(shè)置拖拽監(jiān)聽(tīng)}/** * Helper to load Bitmap from resource */private Bitmap loadBitmap(int resource) { final BitmapFactory.Options options = new BitmapFactory.Options(); options.inPreferredConfig = Bitmap.Config.ARGB_8888; return BitmapFactory.decodeResource(getResources(), resource, options);}/** * 創(chuàng)建Script */private void createBlureScript() { mRS = RenderScript.create(this); mInAllocation = Allocation.createFromBitmap(mRS, bitmap_original); mOutAllocation = Allocation.createFromBitmap(mRS, bitmap_blur); /* * Create intrinsics. RenderScript has built-in features such as blur, * convolve filter etc. These intrinsics are handy for specific * operations without writing RenderScript kernel. In the sample, it's * creating blur, convolve and matrix intrinsics. */ mScriptBlur = ScriptIntrinsicBlur.create(mRS, Element.U8_4(mRS));}3、完成高斯模糊處理代碼。
private void performFilter(Allocation inAllocation, Allocation outAllocation, Bitmap bitmapOut, float value) { /* * 設(shè)置模糊程度。范圍在0~25之間。否則會(huì)出錯(cuò) */ mScriptBlur.setRadius(value); /* * Invoke filter kernel */ mScriptBlur.setInput(inAllocation); mScriptBlur.forEach(outAllocation); outAllocation.copyTo(bitmapOut);}4、將處理后的bitmap設(shè)置到ImageView中。
// Request UI updateimg_blur.setImageBitmap(bitmap_blur);img_blur.invalidate();
基本工作也就完成了。剩下就是代碼的相互調(diào)用了。
【 總 結(jié) 】
其實(shí)總起來(lái)，使用RenderScript進(jìn)行高斯模糊主要是分為三步：
1、創(chuàng)建并初始化需要的對(duì)象（初始化一次就OK）。
mRS = RenderScript.create(this);mScriptBlur = ScriptIntrinsicBlur.create(mRS, Element.U8_4(mRS));//RenderScript的輸入和輸出參數(shù)對(duì)象mInAllocation = Allocation.createFromBitmap(mRS, bitmap_original);mOutAllocation = Allocation.createFromBitmap(mRS, bitmap_blur);
2、執(zhí)行高斯模糊，并將結(jié)果拷貝出來(lái)。
/* * 設(shè)置模糊程度。范圍在0~25之間。否則會(huì)出錯(cuò)（這個(gè)也可以只設(shè)置一次） */mScriptBlur.setRadius(value);/* * Invoke filter kernel */mScriptBlur.setInput(inAllocation);mScriptBlur.forEach(outAllocation);//將結(jié)果拷貝出來(lái)，拷貝到bitmapOut對(duì)象中outAllocation.copyTo(bitmapOut);
3、回收RenderScript對(duì)象
mRS.destory();mRs = null;
文章到此結(jié)束。
按照慣例：下面是我的完整的代碼實(shí)現(xiàn)。
public class MainActivity extends Activity { private SeekBar blurSeekBar; private ImageView img_blur; private Bitmap bitmap_original, bitmap_blur; private RenderScriptTask mLatestTask = null; private RenderScript mRS; private Allocation mInAllocation; private Allocation mOutAllocation; private ScriptIntrinsicBlur mScriptBlur; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); blurSeekBar = (SeekBar) findViewById(R.id.aty_main_seekBar); img_blur = (ImageView) findViewById(R.id.aty_main_img_blur); bitmap_original = loadBitmap(R.drawable.meet_entry_guide_3); // 復(fù)制一份 bitmap_blur = Bitmap.createBitmap(bitmap_original.getWidth(), bitmap_original.getHeight(), bitmap_original.getConfig()); createBlureScript(); setSeekBarListening(); } /** * 設(shè)置SeekBar的監(jiān)聽(tīng) */ private void setSeekBarListening() { blurSeekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() { @Override public void onStopTrackingTouch(SeekBar seekBar) { } @Override public void onStartTrackingTouch(SeekBar seekBar) { } @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { updateImage(progress); } }); } /** * 創(chuàng)建Script */ private void createBlureScript() { mRS = RenderScript.create(this); mInAllocation = Allocation.createFromBitmap(mRS, bitmap_original); mOutAllocation = Allocation.createFromBitmap(mRS, bitmap_blur); /* * Create intrinsics. RenderScript has built-in features such as blur, * convolve filter etc. These intrinsics are handy for specific * operations without writing RenderScript kernel. In the sample, it's * creating blur, convolve and matrix intrinsics. */ mScriptBlur = ScriptIntrinsicBlur.create(mRS, Element.U8_4(mRS)); } private void performFilter(Allocation inAllocation, Allocation outAllocation, Bitmap bitmapOut, float value) { /* * Set blur kernel size */ mScriptBlur.setRadius(value); /* * Invoke filter kernel */ mScriptBlur.setInput(inAllocation); mScriptBlur.forEach(outAllocation); outAllocation.copyTo(bitmapOut); } /* * In the AsyncTask, it invokes RenderScript intrinsics to do a filtering. * After the filtering is done, an operation blocks at Allication.copyTo() * in AsyncTask thread. Once all operation is finished at onPostExecute() in * UI thread, it can invalidate and update ImageView UI. */ private class RenderScriptTask extends AsyncTask<Float, Integer, Integer> { Boolean issued = false; protected Integer doInBackground(Float... values) { if (isCancelled() == false) { issued = true; performFilter(mInAllocation, mOutAllocation, bitmap_blur, values[0]); } return 0; } void updateView(Integer result) { // Request UI update img_blur.setImageBitmap(bitmap_blur); img_blur.invalidate(); } protected void onPostExecute(Integer result) { updateView(result); } protected void onCancelled(Integer result) { if (issued) { updateView(result); } } } /* * Invoke AsynchTask and cancel previous task. When AsyncTasks are piled up * (typically in slow device with heavy kernel), Only the latest (and * already started) task invokes RenderScript operation. */ private void updateImage(int progress) { float f = getBlureParam(progress); if (mLatestTask != null) mLatestTask.cancel(false); mLatestTask = new RenderScriptTask(); mLatestTask.execute(f); } /** * 模糊的值在1 ~ 25之間 * * @param progress * SeekBar的進(jìn)度值(0 ~ 100) * @return 模糊值 */ private float getBlureParam(int progress) { final float max = 25.0f; final float min = 1.f; return (float) ((max - min) * (progress / 100.0) + min); } /** * Helper to load Bitmap from resource */ private Bitmap loadBitmap(int resource) { final BitmapFactory.Options options = new BitmapFactory.Options(); options.inPreferredConfig = Bitmap.Config.ARGB_8888; return BitmapFactory.decodeResource(getResources(), resource, options); }}以上就是本文的全部?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持武林網(wǎng)。
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