Improved performance for Kmeans filter.

Bug: 7739334
Change-Id: I5ab1eb429d65f84449a61deca962a47f2b6dbc8b

1 files changed, 39 insertions, 2 deletions

diff --git a/src/com/android/gallery3d/filtershow/filters/ImageFilterKMeans.java b/src/com/android/gallery3d/filtershow/filters/ImageFilterKMeans.java
index 3c725ac81..f03baca39 100644
--- a/src/com/android/gallery3d/filtershow/filters/ImageFilterKMeans.java
+++ b/src/com/android/gallery3d/filtershow/filters/ImageFilterKMeans.java
@@ -13,13 +13,17 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package com.android.gallery3d.filtershow.filters;
 
 import android.graphics.Bitmap;
+import android.text.format.Time;
 
 import com.android.gallery3d.R;
 
 public class ImageFilterKMeans extends ImageFilter {
+    private int mSeed = 0;
+
     public ImageFilterKMeans() {
         mName = "KMeans";
         mMaxParameter = 20;
@@ -27,9 +31,16 @@ public class ImageFilterKMeans extends ImageFilter {
         mPreviewParameter = 4;
         mDefaultParameter = 4;
         mParameter = 4;
+
+        // set random seed for session
+        Time t = new Time();
+        t.setToNow();
+        mSeed = (int) t.toMillis(false);
     }
 
-    native protected void nativeApplyFilter(Bitmap bitmap, int w, int h, int p);
+    native protected void nativeApplyFilter(Bitmap bitmap, int width, int height,
+            Bitmap large_ds_bm, int lwidth, int lheight, Bitmap small_ds_bm,
+            int swidth, int sheight, int p, int seed);
 
     @Override
     public int getButtonId() {
@@ -50,8 +61,34 @@ public class ImageFilterKMeans extends ImageFilter {
     public Bitmap apply(Bitmap bitmap, float scaleFactor, boolean highQuality) {
         int w = bitmap.getWidth();
         int h = bitmap.getHeight();
+
+        Bitmap large_bm_ds = bitmap;
+        Bitmap small_bm_ds = bitmap;
+
+        // find width/height for larger downsampled bitmap
+        int lw = w;
+        int lh = h;
+        while (lw > 256 && lh > 256) {
+            lw /= 2;
+            lh /= 2;
+        }
+        if (lw != w) {
+            large_bm_ds = Bitmap.createScaledBitmap(bitmap, lw, lh, true);
+        }
+
+        // find width/height for smaller downsampled bitmap
+        int sw = lw;
+        int sh = lh;
+        while (sw > 64 && sh > 64) {
+            sw /= 2;
+            sh /= 2;
+        }
+        if (sw != lw) {
+            small_bm_ds = Bitmap.createScaledBitmap(large_bm_ds, sw, sh, true);
+        }
+
         int p = Math.max(mParameter, mMinParameter) % (mMaxParameter + 1);
-        nativeApplyFilter(bitmap, w, h, p);
+        nativeApplyFilter(bitmap, w, h, large_bm_ds, lw, lh, small_bm_ds, sw, sh, p, mSeed);
         return bitmap;
     }
 }