diff --git a/jni/feature_mos/src/mosaic/AlignFeatures.h b/jni/feature_mos/src/mosaic/AlignFeatures.h
index 19f3905..f003c6a 100644
--- a/jni/feature_mos/src/mosaic/AlignFeatures.h
+++ b/jni/feature_mos/src/mosaic/AlignFeatures.h
@@ -29,30 +29,34 @@
 #include "ImageUtils.h"
 #include "MatrixUtils.h"
 
+#if __cplusplus < 201103L && !defined(__GXX_EXPERIMENTAL_CXX0X__) && !defined(constexpr)
+#define constexpr const
+#endif
+
 class Align {
 
 public:
   // Types of alignment possible
-  static const int ALIGN_TYPE_PAN    = 1;
+  static constexpr int ALIGN_TYPE_PAN    = 1;
 
   // Return codes
-  static const int ALIGN_RET_LOW_TEXTURE  = -2;
-  static const int ALIGN_RET_ERROR        = -1;
-  static const int ALIGN_RET_OK           = 0;
-  static const int ALIGN_RET_FEW_INLIERS  = 1;
+  static constexpr int ALIGN_RET_LOW_TEXTURE  = -2;
+  static constexpr int ALIGN_RET_ERROR        = -1;
+  static constexpr int ALIGN_RET_OK           = 0;
+  static constexpr int ALIGN_RET_FEW_INLIERS  = 1;
 
   ///// Settings for feature-based alignment
   // Number of features to use from corner detection
-  static const int DEFAULT_NR_CORNERS=750;
-  static const double DEFAULT_MAX_DISPARITY=0.1;//0.4;
+  static constexpr int DEFAULT_NR_CORNERS=750;
+  static constexpr double DEFAULT_MAX_DISPARITY=0.1;//0.4;
   // Type of homography to model
-  static const int DEFAULT_MOTION_MODEL=DB_HOMOGRAPHY_TYPE_R_T;
+  static constexpr int DEFAULT_MOTION_MODEL=DB_HOMOGRAPHY_TYPE_R_T;
 // static const int DEFAULT_MOTION_MODEL=DB_HOMOGRAPHY_TYPE_PROJECTIVE;
 //  static const int DEFAULT_MOTION_MODEL=DB_HOMOGRAPHY_TYPE_AFFINE;
-  static const unsigned int DEFAULT_REFERENCE_UPDATE_PERIOD=1500; //  Manual reference frame update so set this to a large number
+  static constexpr unsigned int DEFAULT_REFERENCE_UPDATE_PERIOD=1500; //  Manual reference frame update so set this to a large number
 
-  static const int MIN_NR_REF_CORNERS = 25;
-  static const int MIN_NR_INLIERS = 10;
+  static constexpr int MIN_NR_REF_CORNERS = 25;
+  static constexpr int MIN_NR_INLIERS = 10;
 
   Align();
   ~Align();
diff --git a/jni/feature_mos/src/mosaic/Blend.h b/jni/feature_mos/src/mosaic/Blend.h
index 6371fde..dfc9afa 100644
--- a/jni/feature_mos/src/mosaic/Blend.h
+++ b/jni/feature_mos/src/mosaic/Blend.h
@@ -28,24 +28,28 @@
 #define BLEND_RANGE_DEFAULT 6
 #define BORDER 8
 
+#if __cplusplus < 201103L && !defined(__GXX_EXPERIMENTAL_CXX0X__) && !defined(constexpr)
+#define constexpr const
+#endif
+
 // Percent of total mosaicing time spent on each of the following operations
-const float TIME_PERCENT_ALIGN = 20.0;
-const float TIME_PERCENT_BLEND = 75.0;
-const float TIME_PERCENT_FINAL = 5.0;
+constexpr float TIME_PERCENT_ALIGN = 20.0;
+constexpr float TIME_PERCENT_BLEND = 75.0;
+constexpr float TIME_PERCENT_FINAL = 5.0;
 
 // This threshold determines the minimum separation between the image centers
 // of the input image frames for them to be accepted for blending in the
 // STRIP_TYPE_WIDE mode.
-const float STRIP_SEPARATION_THRESHOLD_PXLS = 10;
+constexpr float STRIP_SEPARATION_THRESHOLD_PXLS = 10;
 
 // This threshold determines the number of pixels on either side of the strip
 // to cross-fade using the images contributing to each seam.
-const float STRIP_CROSS_FADE_WIDTH_PXLS = 2;
+constexpr float STRIP_CROSS_FADE_WIDTH_PXLS = 2;
 // This specifies the maximum pyramid level to which cross-fading is applied.
 // The original image resolution is Level-0, half of that size is Level-1 and
 // so on. BLEND_RANGE_DEFAULT specifies the number of pyramid levels used by
 // the blending algorithm.
-const int STRIP_CROSS_FADE_MAX_PYR_LEVEL = 2;
+constexpr int STRIP_CROSS_FADE_MAX_PYR_LEVEL = 2;
 
 /**
  *  Class for pyramid blending a mosaic.
@@ -54,19 +58,19 @@
 
 public:
 
-  static const int BLEND_TYPE_NONE    = -1;
-  static const int BLEND_TYPE_FULL    = 0;
-  static const int BLEND_TYPE_PAN     = 1;
-  static const int BLEND_TYPE_CYLPAN  = 2;
-  static const int BLEND_TYPE_HORZ   = 3;
+  static constexpr int BLEND_TYPE_NONE    = -1;
+  static constexpr int BLEND_TYPE_FULL    = 0;
+  static constexpr int BLEND_TYPE_PAN     = 1;
+  static constexpr int BLEND_TYPE_CYLPAN  = 2;
+  static constexpr int BLEND_TYPE_HORZ   = 3;
 
-  static const int STRIP_TYPE_THIN      = 0;
-  static const int STRIP_TYPE_WIDE      = 1;
+  static constexpr int STRIP_TYPE_THIN      = 0;
+  static constexpr int STRIP_TYPE_WIDE      = 1;
 
-  static const int BLEND_RET_ERROR        = -1;
-  static const int BLEND_RET_OK           = 0;
-  static const int BLEND_RET_ERROR_MEMORY = 1;
-  static const int BLEND_RET_CANCELLED    = -2;
+  static constexpr int BLEND_RET_ERROR        = -1;
+  static constexpr int BLEND_RET_OK           = 0;
+  static constexpr int BLEND_RET_ERROR_MEMORY = 1;
+  static constexpr int BLEND_RET_CANCELLED    = -2;
 
   Blend();
   ~Blend();
@@ -119,8 +123,8 @@
   void CropFinalMosaic(YUVinfo &imgMos, MosaicRect &cropping_rect);
 
 private:
-   static const float LIMIT_SIZE_MULTIPLIER = 5.0f * 2.0f;
-   static const float LIMIT_HEIGHT_MULTIPLIER = 2.5f;
+   static constexpr float LIMIT_SIZE_MULTIPLIER = 5.0f * 2.0f;
+   static constexpr float LIMIT_HEIGHT_MULTIPLIER = 2.5f;
    int MosaicSizeCheck(float sizeMultiplier, float heightMultiplier);
 };
 
diff --git a/jni/feature_mos/src/mosaic/ImageUtils.cpp b/jni/feature_mos/src/mosaic/ImageUtils.cpp
index 6d0aac0..318df54 100644
--- a/jni/feature_mos/src/mosaic/ImageUtils.cpp
+++ b/jni/feature_mos/src/mosaic/ImageUtils.cpp
@@ -283,7 +283,7 @@
 
   FILE *imgin = NULL;
   int mval=0, format=0, eret;
-  ImageType ret = IMAGE_TYPE_NOIMAGE;
+  ImageType ret = (ImageType)IMAGE_TYPE_NOIMAGE;
 
   imgin = fopen(filename, "r");
   if (imgin == NULL) {
diff --git a/jni/feature_mos_jni.cpp b/jni/feature_mos_jni.cpp
index e40b75a..9e1b2d5 100644
--- a/jni/feature_mos_jni.cpp
+++ b/jni/feature_mos_jni.cpp
@@ -47,8 +47,8 @@
 
 ImageType tImage[NR][MAX_FRAMES];// = {{ImageUtils::IMAGE_TYPE_NOIMAGE}}; // YVU24 format image
 Mosaic *mosaic[NR] = {NULL,NULL};
-ImageType resultYVU = ImageUtils::IMAGE_TYPE_NOIMAGE;
-ImageType resultBGR = ImageUtils::IMAGE_TYPE_NOIMAGE;
+ImageType resultYVU = (ImageType)ImageUtils::IMAGE_TYPE_NOIMAGE;
+ImageType resultBGR = (ImageType)ImageUtils::IMAGE_TYPE_NOIMAGE;
 float gTRS[11]; // 9 elements of the transformation, 1 for frame-number, 1 for alignment error code.
 // Variables to keep track of the mosaic computation progress for both LR & HR.
 float gProgress[NR];