一种快速毛玻璃虚化效果实现

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StackBlur

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public static Bitmap doBlur(Bitmap sentBitmap, int radius, boolean canReuseInBitmap)

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OOM

Èç¹ûÖ±½Ó°ÑÒ»ÕÅ´óÍ¼´«Èë£¬ºÜÈÝÒ×¾Í»á·¢ÉúOOMÄÚ´æÒç³ö

03-11 21:02:02.014 16727-16742/com.wingjay.jayandroid I/art: Clamp target GC heap from 109MB to 96MB
03-11 21:02:02.026 16727-16727/com.wingjay.jayandroid I/art: Clamp target GC heap from 109MB to 96MB
03-11 21:02:02.030 16727-16727/com.wingjay.jayandroid I/art: Clamp target GC heap from 109MB to 96MB
03-11 21:02:02.031 16727-16727/com.wingjay.jayandroid I/art: Forcing collection of SoftReferences for 30MB allocation
03-11 21:02:02.035 16727-16727/com.wingjay.jayandroid I/art: Clamp target GC heap from 109MB to 96MB
03-11 21:02:02.036 16727-16727/com.wingjay.jayandroid E/art: Throwing OutOfMemoryError "Failed to allocate a 32175012 byte allocation with 2648672 free bytes and 2MB until OOM"
03-11 21:02:02.036 16727-16727/com.wingjay.jayandroid D/AndroidRuntime: Shutting down VM

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ReScale

public static Bitmap createScaledBitmap(Bitmap src, int dstWidth, int dstHeight, boolean filter) {}

ÎÒÃÇ¿ÉÒÔÀûÓÃÕâ¸öfunctionÀ´½øÐÐbitmapµÄËõ·Å¡£ÆäÖÐÇ°Èý¸ö²ÎÊýºÜÃ÷ÏÔ£¬ÆäÖÐ¿í¸ßÎÒÃÇ¿ÉÒÔÑ¡ÔñÎªÔÍ¼³ß´çµÄ1/10£»µÚËÄ¸öfilterÊÇÖ¸Ëõ·ÅµÄÐ§¹û£¬filterÎªtrueÔò»áµÃµ½Ò»¸ö±ßÔµÆ½»¬µÄbitmap£¬·´Ö®£¬Ôò»áµÃµ½±ßÔµ¾â³Ý¡¢pixelrelatedµÄbitmap¡£ÕâÀïÎÒÃÇÒª¶ÔËõ·ÅµÄÍ¼Æ¬½øÐÐÐé»¯£¬ËùÒÔÎÞËùÎ½±ßÔµÐ§¹û£¬filter=false¡£

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int scaleRatio = 10;
int blurRadius = 8;
Bitmap scaledBitmap = Bitmap.createScaledBitmap(originBitmap,
    originBitmap.getWidth() / scaleRatio,
    originBitmap.getHeight() / scaleRatio,
    false);
Bitmap blurBitmap = FastBlur.doBlur(scaledBitmap, blurRadius, true);
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setImageBitmap(blurBitmap);

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Ôö´óscaleRatioËõ·Å±È£¬Ê¹ÓÃÒ»Ñù¸üÐ¡µÄbitmapÈ¥Ðé»¯¿ÉÒÔµÃµ½¸üºÃµÄÄ£ºýÐ§¹û£¬¶øÇÒÓÐÀûÓÚÕ¼ÓÃÄÚ´æµÄ¼õÐ¡£»
Ôö´óblurRadius£¬¿ÉÒÔµÃµ½¸ü¸ß³Ì¶ÈµÄÐé»¯£¬²»¹ý»áµ¼ÖÂCPU¸ü¼Óintensive

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scaleRatio = 20
scaleRatio = 35
scaleRatio = 50
scaleRatio = 100

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Performance analysis

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Time Consuming

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long start = System.currentTimeMillis();
Bitmap scaledBitmap, blurBitmap;
int scaleRatio = 10;
int loopCount = 100
for (int i=0; i<loopCount; i++) {
  scaledBitmap = Bitmap.createScaledBitmap(originBitmap,
      originBitmap.getWidth() / scaleRatio,
      originBitmap.getHeight() / scaleRatio,
      false);
  blurBitmap = FastBlur.doBlur(scaledBitmap, 8, true);
}
Log.i("blurtime", String.valueOf(System.currentTimeMillis() - start));

scaleRatio = 10: ºÄÊ±887ms£¬Æ½¾ùºÄÊ±8.87ms;
scaleRatio = 20: ºÄÊ±224ms£¬Æ½¾ùºÄÊ±2.24ms;
scaleRatio = 35: ºÄÊ±99ms£¬Æ½¾ùºÄÊ±0.99ms;
scaleRatio = 50: ºÄÊ±55ms£¬Æ½¾ùºÄÊ±0.55ms;
scaleRatio = 100: ºÄÊ±29ms£¬Æ½¾ùºÄÊ±0.29ms;

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Memory Consuming

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