使用Renderscript的Android模糊问题

Question

I am using following code for building blurred background for my imageview.

public class BlurBuilder {
    private static final float BITMAP_SCALE = 0.2f;
    private static final float BLUR_RADIUS = 25f;

    public static Bitmap blur(Context context, Bitmap image) {
        int width = Math.round(image.getWidth() * BITMAP_SCALE);
        int height = Math.round(image.getHeight() * BITMAP_SCALE);

        Bitmap inputBitmap = Bitmap.createScaledBitmap(image, width, height, false);
        Bitmap outputBitmap = Bitmap.createBitmap(inputBitmap);

        RenderScript rs = RenderScript.create(context);
        ScriptIntrinsicBlur theIntrinsic = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
        Allocation tmpIn = Allocation.createFromBitmap(rs, inputBitmap);
        Allocation tmpOut = Allocation.createFromBitmap(rs, outputBitmap);
        theIntrinsic.setRadius(BLUR_RADIUS);
        theIntrinsic.setInput(tmpIn);
        theIntrinsic.forEach(tmpOut);
        tmpOut.copyTo(outputBitmap);

        return outputBitmap;
    }
}

Blur is built fine for most times, but get bad over time, eventually my app crashes without any crash log. Upon running on emulator, I have seen the following error after severe testing:

09-01 15:05:03.230 4624-9758/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.238 4624-9781/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.242 4624-10128/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.242 4624-9610/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.242 4624-9781/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.250 4624-9767/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.254 4624-9758/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
... (same error - many more times and then crash)

I have following queries in this regard:

1. I am using following gradle config for renderscript:

   compileSdkVersion 23 buildToolsVersion "23.0.3"

   defaultConfig { applicationId "package " minSdkVersion 19 targetSdkVersion 23 multiDexEnabled true renderscriptTargetApi 19 renderscriptSupportModeEnabled true }

What is the recommended version of renderscript library ? Should I import dependencies from android.support.v8.renderscript.Allocation or android.renderscript` package ?

2. Can I achieve the blur effect without using renderscript library ?

Answer 1

After spending more than a day, I figured out the following:

1. App is crashing because there is an exception being thrown by Renderscript library. This usually happens often in devices with low processing power. This exception is not a Java exception, cannot be caught.

2. Use the following code for another way to issue blur (without using renderscript library):

    public static Bitmap fastblur(Bitmap sentBitmap) { int radius = (int) BLUR_RADIUS; int width = Math.round(sentBitmap.getWidth() * BITMAP_SCALE); int height = Math.round(sentBitmap.getHeight() * BITMAP_SCALE); sentBitmap = Bitmap.createScaledBitmap(sentBitmap, width, height, false); Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true); if (radius < 1) { return (null); } int w = bitmap.getWidth(); int h = bitmap.getHeight(); int[] pix = new int[w * h]; Log.e("pix", w + " " + h + " " + pix.length); bitmap.getPixels(pix, 0, w, 0, 0, w, h); int wm = w - 1; int hm = h - 1; int wh = w * h; int div = radius + radius + 1; int r[] = new int[wh]; int g[] = new int[wh]; int b[] = new int[wh]; int rsum, gsum, bsum, x, y, i, p, yp, yi, yw; int vmin[] = new int[Math.max(w, h)]; int divsum = (div + 1) >> 1; divsum *= divsum; int dv[] = new int[256 * divsum]; for (i = 0; i < 256 * divsum; i++) { dv[i] = (i / divsum); } yw = yi = 0; int[][] stack = new int[div][3]; int stackpointer; int stackstart; int[] sir; int rbs; int r1 = radius + 1; int routsum, goutsum, boutsum; int rinsum, ginsum, binsum; for (y = 0; y < h; y++) { rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0; for (i = -radius; i <= radius; i++) { p = pix[yi + Math.min(wm, Math.max(i, 0))]; sir = stack[i + radius]; sir[0] = (p & 0xff0000) >> 16; sir[1] = (p & 0x00ff00) >> 8; sir[2] = (p & 0x0000ff); rbs = r1 - Math.abs(i); rsum += sir[0] * rbs; gsum += sir[1] * rbs; bsum += sir[2] * rbs; if (i > 0) { rinsum += sir[0]; ginsum += sir[1]; binsum += sir[2]; } else { routsum += sir[0]; goutsum += sir[1]; boutsum += sir[2]; } } stackpointer = radius; for (x = 0; x < w; x++) { r[yi] = dv[rsum]; g[yi] = dv[gsum]; b[yi] = dv[bsum]; rsum -= routsum; gsum -= goutsum; bsum -= boutsum; stackstart = stackpointer - radius + div; sir = stack[stackstart % div]; routsum -= sir[0]; goutsum -= sir[1]; boutsum -= sir[2]; if (y == 0) { vmin[x] = Math.min(x + radius + 1, wm); } p = pix[yw + vmin[x]]; sir[0] = (p & 0xff0000) >> 16; sir[1] = (p & 0x00ff00) >> 8; sir[2] = (p & 0x0000ff); rinsum += sir[0]; ginsum += sir[1]; binsum += sir[2]; rsum += rinsum; gsum += ginsum; bsum += binsum; stackpointer = (stackpointer + 1) % div; sir = stack[(stackpointer) % div]; routsum += sir[0]; goutsum += sir[1]; boutsum += sir[2]; rinsum -= sir[0]; ginsum -= sir[1]; binsum -= sir[2]; yi++; } yw += w; } for (x = 0; x < w; x++) { rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0; yp = -radius * w; for (i = -radius; i <= radius; i++) { yi = Math.max(0, yp) + x; sir = stack[i + radius]; sir[0] = r[yi]; sir[1] = g[yi]; sir[2] = b[yi]; rbs = r1 - Math.abs(i); rsum += r[yi] * rbs; gsum += g[yi] * rbs; bsum += b[yi] * rbs; if (i > 0) { rinsum += sir[0]; ginsum += sir[1]; binsum += sir[2]; } else { routsum += sir[0]; goutsum += sir[1]; boutsum += sir[2]; } if (i < hm) { yp += w; } } yi = x; stackpointer = radius; for (y = 0; y < h; y++) { // Preserve alpha channel: ( 0xff000000 & pix[yi] ) pix[yi] = ( 0xff000000 & pix[yi] ) | ( dv[rsum] << 16 ) | ( dv[gsum] << 8 ) | dv[bsum]; rsum -= routsum; gsum -= goutsum; bsum -= boutsum; stackstart = stackpointer - radius + div; sir = stack[stackstart % div]; routsum -= sir[0]; goutsum -= sir[1]; boutsum -= sir[2]; if (x == 0) { vmin[y] = Math.min(y + r1, hm) * w; } p = x + vmin[y]; sir[0] = r[p]; sir[1] = g[p]; sir[2] = b[p]; rinsum += sir[0]; ginsum += sir[1]; binsum += sir[2]; rsum += rinsum; gsum += ginsum; bsum += binsum; stackpointer = (stackpointer + 1) % div; sir = stack[stackpointer]; routsum += sir[0]; goutsum += sir[1]; boutsum += sir[2]; rinsum -= sir[0]; ginsum -= sir[1]; binsum -= sir[2]; yi += w; } } Log.e("pix", w + " " + h + " " + pix.length); bitmap.setPixels(pix, 0, w, 0, 0, w, h); return (bitmap); }