Blending algorithm updates to support WIDE strip-based blending.

1) Added algorithm to select wider strips (and made it the default mode in the app).
2) Added algorithm to cross-fade blend between the wider strips.

Change-Id: I744e69edb16a20f0040ee82c3390548b78853087

2 files changed, 27 insertions, 0 deletions

diff --git a/src/com/android/camera/panorama/Mosaic.java b/src/com/android/camera/panorama/Mosaic.java
index b586aad..9ad2c64 100644
--- a/src/com/android/camera/panorama/Mosaic.java
+++ b/src/com/android/camera/panorama/Mosaic.java
@@ -68,6 +68,21 @@ public class Mosaic {
     public static final int BLENDTYPE_HORIZONTAL =3;
 
     /**
+     * This strip type will use the default thin strips where the strips are
+     * spaced according to the image capture rate.
+     */
+    public static final int STRIPTYPE_THIN = 0;
+
+    /**
+     * This strip type will use wider strips for blending. The strip separation
+     * is controlled by a threshold on the native side. Since the strips are
+     * wider, there is an additional cross-fade blending step to make the seam
+     * boundaries smoother. Since this mode uses lesser image frames, it is
+     * computationally more efficient than the thin strip mode.
+     */
+    public static final int STRIPTYPE_WIDE = 1;
+
+    /**
      * Return flags returned by createMosaic() are one of the following.
      */
     public static final int MOSAIC_RET_OK = 1;
@@ -128,6 +143,13 @@ public class Mosaic {
     public native void setBlendingType(int type);
 
     /**
+     * Set the type of strips to use for blending.
+     * @param type the blending strip type to use {STRIPTYPE_THIN,
+     * STRIPTYPE_WIDE}.
+     */
+    public native void setStripType(int type);
+
+    /**
      * Tell the native layer to create the final mosaic after all the input frame
      * data have been collected.
      * The case of generating high-resolution mosaic may take dozens of seconds to finish.
diff --git a/src/com/android/camera/panorama/MosaicFrameProcessor.java b/src/com/android/camera/panorama/MosaicFrameProcessor.java
index dde4a22..54fc7b8 100644
--- a/src/com/android/camera/panorama/MosaicFrameProcessor.java
+++ b/src/com/android/camera/panorama/MosaicFrameProcessor.java
@@ -84,6 +84,7 @@ public class MosaicFrameProcessor {
 
     public void initialize() {
         setupMosaicer(mPreviewWidth, mPreviewHeight, mPreviewBufferSize);
+        setStripType(Mosaic.STRIPTYPE_WIDE);
         reset();
     }
 
@@ -92,6 +93,10 @@ public class MosaicFrameProcessor {
         mMosaicer.freeMosaicMemory();
     }
 
+    public void setStripType(int type) {
+        mMosaicer.setStripType(type);
+    }
+
     private void setupMosaicer(int previewWidth, int previewHeight, int bufSize) {
         Log.v(TAG, "setupMosaicer w, h=" + previewWidth + ',' + previewHeight + ',' + bufSize);
         mMosaicer.allocateMosaicMemory(previewWidth, previewHeight);