- 关于高斯模糊效果的实现
public class BitmapLoader {
private Context mContext;
public BitmapLoader(Context context) {
this.mContext = context.getApplicationContext();
}
private static volatile BitmapLoader sInst = null;
public static BitmapLoader getInstance(Context context) {
BitmapLoader inst = sInst;
if (inst == null) {
synchronized (BitmapLoader.class) {
inst = sInst;
if (inst == null) {
inst = new BitmapLoader(context);
sInst = inst;
}
}
}
return inst;
}
public Drawable getDrawable(Activity activity, int blurRadius) {
if (activity == null) {
L.e("getDrawable : Activity == null");
return null;
}
View adverView = activity.getWindow().getDecorView();
if (adverView == null) {
L.e("getDrawable : adverView == null");
return null;
}
// 获取状态栏的高度
Rect rect = new Rect();
adverView.getWindowVisibleDisplayFrame(rect);
int statusBarHeights = rect.top;
Display display = activity.getWindowManager().getDefaultDisplay();
// 获取屏幕宽和高
int widths = display.getWidth();
int heights = display.getHeight();
adverView.setDrawingCacheEnabled(true);
adverView.buildDrawingCache();
Bitmap bitmap = Bitmap.createBitmap(adverView.getDrawingCache(false), 0, statusBarHeights, widths, heights - statusBarHeights);
if (bitmap == null) {
return null;
}
L.i("getDrawable_bitmap_" + bitmap);
Drawable drawable = new BitmapDrawable(doBlur(ImageUtility.getImageThumbnail(bitmap), blurRadius));
L.i("getDrawable_drawable_" + drawable);
if (bitmap != null) bitmap.recycle();
return drawable;
}
/***
* 高斯模糊
* 优化
*
* @param mBitmap
* @return
*/
private Bitmap doBlur(Bitmap mBitmap, int blurRadius) {
if (mBitmap == null) {
return null;
}
int width = mBitmap.getWidth();
int height = mBitmap.getHeight();
Bitmap scaledBitmap = Bitmap.createScaledBitmap(mBitmap, width, height, true);
if (mBitmap != null) mBitmap.recycle();
return doBlur(scaledBitmap, blurRadius, false);
}
/**
* 高斯模糊核心算法
*/
private Bitmap doBlur(Bitmap sentBitmap, int radius, boolean canReuseInBitmap) {
if (sentBitmap == null) {
return sentBitmap;
}
Bitmap bitmap;
if (canReuseInBitmap) {
bitmap = sentBitmap;
} else {
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];
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;
}
}
bitmap.setPixels(pix, 0, w, 0, 0, w, h);
return (bitmap);
}
/**
* 高斯模糊核心算法
*
* @param in
* @param out
* @param width
* @param height
* @param radius
*/
private void blur(int[] in, int[] out, int width, int height, float radius) {
int widthMinus1 = width - 1;
int r = (int) radius;
int tableSize = 2 * r + 1;
int divide[] = new int[256 * tableSize];
for (int i = 0; i < 256 * tableSize; i++)
divide[i] = i / tableSize;
int inIndex = 0;
for (int y = 0; y < height; y++) {
int outIndex = y;
int ta = 0, tr = 0, tg = 0, tb = 0;
for (int i = -r; i <= r; i++) {
int rgb = in[inIndex + clamp(i, 0, width - 1)];
ta += (rgb >> 24) & 0xff;
tr += (rgb >> 16) & 0xff;
tg += (rgb >> 8) & 0xff;
tb += rgb & 0xff;
}
for (int x = 0; x < width; x++) {
out[outIndex] = (divide[ta] << 24) | (divide[tr] << 16) | (divide[tg] << 8) | divide[tb];
int i1 = x + r + 1;
if (i1 > widthMinus1)
i1 = widthMinus1;
int i2 = x - r;
if (i2 < 0)
i2 = 0;
int rgb1 = in[inIndex + i1];
int rgb2 = in[inIndex + i2];
ta += ((rgb1 >> 24) & 0xff) - ((rgb2 >> 24) & 0xff);
tr += ((rgb1 & 0xff0000) - (rgb2 & 0xff0000)) >> 16;
tg += ((rgb1 & 0xff00) - (rgb2 & 0xff00)) >> 8;
tb += (rgb1 & 0xff) - (rgb2 & 0xff);
outIndex += height;
}
inIndex += width;
}
}
private void blurFractional(int[] in, int[] out, int width, int height, float radius) {
radius -= (int) radius;
float f = 1.0f / (1 + 2 * radius);
int inIndex = 0;
for (int y = 0; y < height; y++) {
int outIndex = y;
out[outIndex] = in[0];
outIndex += height;
for (int x = 1; x < width - 1; x++) {
int i = inIndex + x;
int rgb1 = in[i - 1];
int rgb2 = in[i];
int rgb3 = in[i + 1];
int a1 = (rgb1 >> 24) & 0xff;
int r1 = (rgb1 >> 16) & 0xff;
int g1 = (rgb1 >> 8) & 0xff;
int b1 = rgb1 & 0xff;
int a2 = (rgb2 >> 24) & 0xff;
int r2 = (rgb2 >> 16) & 0xff;
int g2 = (rgb2 >> 8) & 0xff;
int b2 = rgb2 & 0xff;
int a3 = (rgb3 >> 24) & 0xff;
int r3 = (rgb3 >> 16) & 0xff;
int g3 = (rgb3 >> 8) & 0xff;
int b3 = rgb3 & 0xff;
a1 = a2 + (int) ((a1 + a3) * radius);
r1 = r2 + (int) ((r1 + r3) * radius);
g1 = g2 + (int) ((g1 + g3) * radius);
b1 = b2 + (int) ((b1 + b3) * radius);
a1 *= f;
r1 *= f;
g1 *= f;
b1 *= f;
out[outIndex] = (a1 << 24) | (r1 << 16) | (g1 << 8) | b1;
outIndex += height;
}
out[outIndex] = in[width - 1];
inIndex += width;
}
}
private int clamp(int x, int a, int b) {
return (x < a) ? a : (x > b) ? b : x;
}
}
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