2D CPU version for constrained diffusion

6 files changed, 349 insertions, 10 deletions

diff --git a/build/run.sh b/build/run.sh
index e6f171e..b40d222 100755
--- a/build/run.sh
+++ b/build/run.sh
@@ -1,14 +1,14 @@
 #!/bin/bash
 echo "Building CCPi-regularisation Toolkit using CMake"
-rm -r build_proj
+rm -r ../build_proj
 # Requires Cython, install it first:
 # pip install cython
-mkdir build_proj
-cd build_proj/
+mkdir ../build_proj
+cd ../build_proj/
 #make clean
-export CIL_VERSION=19.03
+export CIL_VERSION=19.04
 # install Python modules without CUDA
-# cmake ../ -DBUILD_PYTHON_WRAPPER=ON -DBUILD_MATLAB_WRAPPER=OFF -DBUILD_CUDA=OFF -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=./install
+cmake ../ -DBUILD_PYTHON_WRAPPER=ON -DBUILD_MATLAB_WRAPPER=OFF -DBUILD_CUDA=OFF -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=./install
 # install Python modules with CUDA
 # cmake ../ -DBUILD_PYTHON_WRAPPER=ON -DBUILD_MATLAB_WRAPPER=OFF -DBUILD_CUDA=ON -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=./install
 # install Matlab modules without CUDA
@@ -18,12 +18,12 @@ export CIL_VERSION=19.03
 # cmake ../ -DBUILD_PYTHON_WRAPPER=OFF -DMatlab_ROOT_DIR=/home/algol/SOFT/MATLAB9/ -DBUILD_MATLAB_WRAPPER=ON -DBUILD_CUDA=ON -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=./install
 make install
 ############### Python(linux)###############
-#cp install/lib/libcilreg.so install/python/ccpi/filters
-# cd install/python
-# export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:../lib
+cp install/lib/libcilreg.so install/python/ccpi/filters
+cd install/python
+export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:../lib
 # spyder
 ############### Matlab(linux)###############
-export LD_PRELOAD=/home/algol/anaconda3/lib/libstdc++.so.6  # if there is libstdc error in matlab
+# export LD_PRELOAD=/home/algol/anaconda3/lib/libstdc++.so.6  # if there is libstdc error in matlab
 # PATH="/path/to/mex/:$PATH" LD_LIBRARY_PATH="/path/to/library:$LD_LIBRARY_PATH" matlab
 # PATH="/home/kjy41806/Documents/SOFT/CCPi-Regularisation-Toolkit/build_proj/install/matlab/:$PATH" LD_LIBRARY_PATH="/home/kjy41806/Documents/SOFT/CCPi-Regularisation-Toolkit/build_proj/install/lib:$LD_LIBRARY_PATH" matlab
 #PATH="/home/algol/Documents/DEV/CCPi-Regularisation-Toolkit/build_proj/install/matlab/:$PATH" LD_LIBRARY_PATH="/home/algol/Documents/DEV/CCPi-Regularisation-Toolkit/build_proj/install/lib:$LD_LIBRARY_PATH" /home/algol/SOFT/MATLAB9/bin/matlab
diff --git a/src/Core/CMakeLists.txt b/src/Core/CMakeLists.txt
index b3c0dfb..6975a89 100644
--- a/src/Core/CMakeLists.txt
+++ b/src/Core/CMakeLists.txt
@@ -68,6 +68,7 @@ add_library(cilreg SHARED
 	    ${CMAKE_CURRENT_SOURCE_DIR}/regularisers_CPU/SB_TV_core.c
 	    ${CMAKE_CURRENT_SOURCE_DIR}/regularisers_CPU/TGV_core.c
 	    ${CMAKE_CURRENT_SOURCE_DIR}/regularisers_CPU/Diffusion_core.c
+    	    ${CMAKE_CURRENT_SOURCE_DIR}/regularisers_CPU/DiffusionMASK_core.c
 	    ${CMAKE_CURRENT_SOURCE_DIR}/regularisers_CPU/Diffus4th_order_core.c
 	    ${CMAKE_CURRENT_SOURCE_DIR}/regularisers_CPU/LLT_ROF_core.c
         ${CMAKE_CURRENT_SOURCE_DIR}/regularisers_CPU/ROF_TV_core.c
diff --git a/src/Core/regularisers_CPU/DiffusionMASK_core.c b/src/Core/regularisers_CPU/DiffusionMASK_core.c
new file mode 100644
index 0000000..eef173d
--- /dev/null
+++ b/src/Core/regularisers_CPU/DiffusionMASK_core.c
@@ -0,0 +1,214 @@
+/*
+ * This work is part of the Core Imaging Library developed by
+ * Visual Analytics and Imaging System Group of the Science Technology
+ * Facilities Council, STFC
+ *
+ * Copyright 2017 Daniil Kazantsev
+ * Copyright 2017 Srikanth Nagella, Edoardo Pasca
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "DiffusionMASK_core.h"
+#include "utils.h"
+
+#define EPS 1.0e-5
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+/*sign function*/
+int signNDF_m(float x) {
+    return (x > 0) - (x < 0);
+}
+
+/* C-OMP implementation of linear and nonlinear diffusion [1,2] which is constrained by the provided MASK.
+ * The minimisation is performed using explicit scheme.
+ * Implementation using the diffusivity window to increase the coverage area of the diffusivity
+ *
+ * Input Parameters:
+ * 1. Noisy image/volume
+ * 2. MASK (in unsigned char format)
+ * 3. Diffusivity window (half-size of the searching window, e.g. 3) 	 
+ * 4. lambda - regularization parameter
+ * 5. Edge-preserving parameter (sigma), when sigma equals to zero nonlinear diffusion -> linear diffusion
+ * 6. Number of iterations, for explicit scheme >= 150 is recommended
+ * 7. tau - time-marching step for explicit scheme
+ * 8. Penalty type: 1 - Huber, 2 - Perona-Malik, 3 - Tukey Biweight
+ * 9. eplsilon - tolerance constant
+
+ * Output:
+ * [1] Filtered/regularized image/volume
+ * [2] Information vector which contains [iteration no., reached tolerance]
+ *
+ * This function is based on the paper by
+ * [1] Perona, P. and Malik, J., 1990. Scale-space and edge detection using anisotropic diffusion. IEEE Transactions on pattern analysis and machine intelligence, 12(7), pp.629-639.
+ * [2] Black, M.J., Sapiro, G., Marimont, D.H. and Heeger, D., 1998. Robust anisotropic diffusion. IEEE Transactions on image processing, 7(3), pp.421-432.
+ */
+
+float DiffusionMASK_CPU_main(float *Input, unsigned char *MASK, float *Output, float *infovector, int DiffusWindow, float lambdaPar, float sigmaPar, int iterationsNumb, float tau, int penaltytype, float epsil, int dimX, int dimY, int dimZ)
+{
+    int i,j,k,counterG;
+    float sigmaPar2, *Output_prev=NULL, *Eucl_Vec;
+    int DiffusWindow_tot;
+    sigmaPar2 = sigmaPar/sqrt(2.0f);
+    long DimTotal;
+    float re, re1;
+    re = 0.0f; re1 = 0.0f;
+    int count = 0;
+    DimTotal = (long)(dimX*dimY*dimZ);
+
+    if (dimZ == 1) {
+	DiffusWindow_tot = (2*DiffusWindow + 1)*(2*DiffusWindow + 1);
+        /* generate a 2D Gaussian kernel for NLM procedure */
+        Eucl_Vec = (float*) calloc (DiffusWindow_tot,sizeof(float));
+        counterG = 0;
+        for(i=-DiffusWindow; i<=DiffusWindow; i++) {
+            for(j=-DiffusWindow; j<=DiffusWindow; j++) {
+                Eucl_Vec[counterG] = (float)expf(-(powf(((float) i), 2) + powf(((float) j), 2))/(2.0f*DiffusWindow*DiffusWindow));
+                counterG++;
+            }} /*main neighb loop */
+       }
+    else {
+	DiffusWindow_tot = (2*DiffusWindow + 1)*(2*DiffusWindow + 1)*(2*DiffusWindow + 1);
+	Eucl_Vec = (float*) calloc (DiffusWindow_tot,sizeof(float));
+        counterG = 0;
+        for(i=-DiffusWindow; i<=DiffusWindow; i++) {
+            for(j=-DiffusWindow; j<=DiffusWindow; j++) {
+                for(k=-DiffusWindow; k<=DiffusWindow; k++) {
+                    Eucl_Vec[counterG] = (float)expf(-(powf(((float) i), 2) + powf(((float) j), 2) + powf(((float) k), 2))/(2*DiffusWindow*DiffusWindow*DiffusWindow));
+                    counterG++;
+                }}} /*main neighb loop */            
+    }
+
+    if (epsil != 0.0f) Output_prev = calloc(DimTotal, sizeof(float));
+
+    /* copy into output */
+    copyIm(Input, Output, (long)(dimX), (long)(dimY), (long)(dimZ));
+
+    for(i=0; i < iterationsNumb; i++) {
+
+      if ((epsil != 0.0f)  && (i % 5 == 0)) copyIm(Output, Output_prev, (long)(dimX), (long)(dimY), (long)(dimZ));
+      if (dimZ == 1) {
+	    /* running 2D diffusion iterations */
+            if (sigmaPar == 0.0f) LinearDiff_MASK2D(Input, MASK, Output, Eucl_Vec, DiffusWindow, lambdaPar, tau, (long)(dimX), (long)(dimY)); /* constrained linear diffusion */
+            else NonLinearDiff_MASK2D(Input, MASK, Output, Eucl_Vec, DiffusWindow, lambdaPar, sigmaPar2, tau, penaltytype, (long)(dimX), (long)(dimY)); /* constrained nonlinear diffusion */
+          }
+      else {
+       	/* running 3D diffusion iterations */
+        //if (sigmaPar == 0.0f) LinearDiff3D(Input, Output, lambdaPar, tau, (long)(dimX), (long)(dimY), (long)(dimZ));
+//       else NonLinearDiff3D(Input, Output, lambdaPar, sigmaPar2, tau, penaltytype, (long)(dimX), (long)(dimY), (long)(dimZ));
+          }
+          /* check early stopping criteria if epsilon not equal zero */
+          if ((epsil != 0.0f)  && (i % 5 == 0)) {
+          re = 0.0f; re1 = 0.0f;
+            for(j=0; j<DimTotal; j++)
+            {
+                re += powf(Output[j] - Output_prev[j],2);
+                re1 += powf(Output[j],2);
+            }
+          re = sqrtf(re)/sqrtf(re1);
+          /* stop if the norm residual is less than the tolerance EPS */
+          if (re < epsil)  count++;
+          if (count > 3) break;
+          }
+		}
+
+    free(Output_prev);
+  /*adding info into info_vector */
+    infovector[0] = (float)(i);  /*iterations number (if stopped earlier based on tolerance)*/
+    infovector[1] = re;  /* reached tolerance */
+    return 0;
+}
+
+
+/********************************************************************/
+/***************************2D Functions*****************************/
+/********************************************************************/
+/* MASKED-constrained 2D linear diffusion (PDE heat equation) */
+float LinearDiff_MASK2D(float *Input, unsigned char *MASK, float *Output,  float *Eucl_Vec, int DiffusWindow, float lambdaPar, float tau, long dimX, long dimY)
+{
+
+long i,j,i1,j1,i_m,j_m,index,indexneighb,counter;
+unsigned char class_c, class_n;
+float diffVal;
+
+#pragma omp parallel for shared(Input) private(index,i,j,i1,j1,i_m,j_m,counter,diffVal,indexneighb,class_c,class_n)
+    for(i=0; i<dimX; i++) {
+        for(j=0; j<dimY; j++) {        
+        index = j*dimX+i; /* current pixel index */
+        counter = 0; diffVal = 0.0f;
+        for(i_m=-DiffusWindow; i_m<=DiffusWindow; i_m++) {
+            for(j_m=-DiffusWindow; j_m<=DiffusWindow; j_m++) {		
+            i1 = i+i_m;
+            j1 = j+j_m;
+            if (((i1 >= 0) && (i1 < dimX)) && ((j1 >= 0) && (j1 < dimY))) {                   
+            indexneighb = j1*dimX+i1; /* neighbour pixel index */
+	    class_c = MASK[index]; /* current class value */
+    	    class_n = MASK[indexneighb]; /* neighbour class value */
+	    
+	    /* perform diffusion only within the same class (given by MASK) */
+	    if (class_n == class_c) diffVal += Output[indexneighb] - Output[index];
+            }
+		counter++;
+	    }}
+            Output[index] += tau*(lambdaPar*(diffVal) - (Output[index] - Input[index]));
+        }}
+	return *Output;
+}
+
+/*  MASKED-constrained 2D nonlinear diffusion */
+float NonLinearDiff_MASK2D(float *Input, unsigned char *MASK, float *Output, float *Eucl_Vec, int DiffusWindow, float lambdaPar, float sigmaPar, float tau, int penaltytype, long dimX, long dimY)
+{
+	long i,j,i1,j1,i_m,j_m,index,indexneighb,counter;
+	unsigned char class_c, class_n;
+	float diffVal, funcVal;
+	
+#pragma omp parallel for shared(Input) private(index,i,j,i1,j1,i_m,j_m,counter,diffVal,funcVal,indexneighb,class_c,class_n)
+    for(i=0; i<dimX; i++) {
+        for(j=0; j<dimY; j++) {        
+        index = j*dimX+i; /* current pixel index */
+        counter = 0; diffVal = 0.0f; funcVal = 0.0f;
+        for(i_m=-DiffusWindow; i_m<=DiffusWindow; i_m++) {
+            for(j_m=-DiffusWindow; j_m<=DiffusWindow; j_m++) {		
+            i1 = i+i_m;
+            j1 = j+j_m;
+            if (((i1 >= 0) && (i1 < dimX)) && ((j1 >= 0) && (j1 < dimY))) {                   
+            indexneighb = j1*dimX+i1; /* neighbour pixel index */
+	    class_c = MASK[index]; /* current class value */
+    	    class_n = MASK[indexneighb]; /* neighbour class value */
+	    
+	    /* perform diffusion only within the same class (given by MASK) */
+	    if (class_n == class_c) {
+	    	diffVal = Output[indexneighb] - Output[index];
+	    	if (penaltytype == 1) {
+	        /* Huber penalty */
+                if (fabs(diffVal) > sigmaPar) funcVal += signNDF_m(diffVal);
+                else funcVal += diffVal/sigmaPar; }
+  		else if (penaltytype == 2) {
+  		/* Perona-Malik */
+  		funcVal += (diffVal)/(1.0f + powf((diffVal/sigmaPar),2)); }
+  		else if (penaltytype == 3) {
+  		/* Tukey Biweight */
+  		if (fabs(diffVal) <= sigmaPar) funcVal += diffVal*powf((1.0f - powf((diffVal/sigmaPar),2)), 2); }
+                else {
+                printf("%s \n", "No penalty function selected! Use Huber,2 or 3.");
+		break; }  		  
+            		}
+            	}
+		counter++;
+	    }}
+           Output[index] += tau*(lambdaPar*(funcVal) - (Output[index] - Input[index]));
+		}}
+	return *Output;
+}
+/********************************************************************/
+/***************************3D Functions*****************************/
+/********************************************************************/
diff --git a/src/Core/regularisers_CPU/DiffusionMASK_core.h b/src/Core/regularisers_CPU/DiffusionMASK_core.h
new file mode 100644
index 0000000..8890c73
--- /dev/null
+++ b/src/Core/regularisers_CPU/DiffusionMASK_core.h
@@ -0,0 +1,62 @@
+/*
+This work is part of the Core Imaging Library developed by
+Visual Analytics and Imaging System Group of the Science Technology
+Facilities Council, STFC
+
+Copyright 2017 Daniil Kazantsev
+Copyright 2017 Srikanth Nagella, Edoardo Pasca
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#include <math.h>
+#include <stdlib.h>
+#include <memory.h>
+#include <stdio.h>
+#include "omp.h"
+#include "utils.h"
+#include "CCPiDefines.h"
+
+
+/* C-OMP implementation of linear and nonlinear diffusion [1,2] which is constrained by the provided MASK.
+ * The minimisation is performed using explicit scheme.
+ * Implementation using the Diffusivity window to increase the coverage area of the diffusivity
+ *
+ * Input Parameters:
+ * 1. Noisy image/volume
+ * 2. MASK (in unsigned short format)
+ * 3. Diffusivity window (half-size of the searching window, e.g. 3) 	 
+ * 4. lambda - regularization parameter
+ * 5. Edge-preserving parameter (sigma), when sigma equals to zero nonlinear diffusion -> linear diffusion
+ * 6. Number of iterations, for explicit scheme >= 150 is recommended
+ * 7. tau - time-marching step for explicit scheme
+ * 8. Penalty type: 1 - Huber, 2 - Perona-Malik, 3 - Tukey Biweight
+ * 9. eplsilon - tolerance constant
+
+ * Output:
+ * [1] Filtered/regularized image/volume
+ * [2] Information vector which contains [iteration no., reached tolerance]
+ *
+ * This function is based on the paper by
+ * [1] Perona, P. and Malik, J., 1990. Scale-space and edge detection using anisotropic diffusion. IEEE Transactions on pattern analysis and machine intelligence, 12(7), pp.629-639.
+ * [2] Black, M.J., Sapiro, G., Marimont, D.H. and Heeger, D., 1998. Robust anisotropic diffusion. IEEE Transactions on image processing, 7(3), pp.421-432.
+ */
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+CCPI_EXPORT float DiffusionMASK_CPU_main(float *Input, unsigned char *MASK, float *Output, float *infovector, int DiffusWindow, float lambdaPar, float sigmaPar, int iterationsNumb, float tau, int penaltytype, float epsil, int dimX, int dimY, int dimZ);
+CCPI_EXPORT float LinearDiff_MASK2D(float *Input, unsigned char *MASK, float *Output,  float *Eucl_Vec, int DiffusWindow, float lambdaPar, float tau, long dimX, long dimY);
+CCPI_EXPORT float NonLinearDiff_MASK2D(float *Input, unsigned char *MASK, float *Output, float *Eucl_Vec, int DiffusWindow, float lambdaPar, float sigmaPar, float tau, int penaltytype, long dimX, long dimY);
+#ifdef __cplusplus
+}
+#endif
diff --git a/src/Python/ccpi/filters/regularisers.py b/src/Python/ccpi/filters/regularisers.py
index 398e11c..1e427bf 100644
--- a/src/Python/ccpi/filters/regularisers.py
+++ b/src/Python/ccpi/filters/regularisers.py
@@ -2,7 +2,7 @@
 script which assigns a proper device core function based on a flag ('cpu' or 'gpu')
 """
 
-from ccpi.filters.cpu_regularisers import TV_ROF_CPU, TV_FGP_CPU, TV_SB_CPU, dTV_FGP_CPU, TNV_CPU, NDF_CPU, Diff4th_CPU, TGV_CPU, LLT_ROF_CPU, PATCHSEL_CPU, NLTV_CPU
+from ccpi.filters.cpu_regularisers import TV_ROF_CPU, TV_FGP_CPU, TV_SB_CPU, dTV_FGP_CPU, TNV_CPU, NDF_CPU, NDF_MASK_CPU, Diff4th_CPU, TGV_CPU, LLT_ROF_CPU, PATCHSEL_CPU, NLTV_CPU
 try:
     from ccpi.filters.gpu_regularisers import TV_ROF_GPU, TV_FGP_GPU, TV_SB_GPU, dTV_FGP_GPU, NDF_GPU, Diff4th_GPU, TGV_GPU, LLT_ROF_GPU, PATCHSEL_GPU
     gpu_enabled = True
@@ -127,6 +127,31 @@ def NDF(inputData, regularisation_parameter, edge_parameter, iterations,
     	    raise ValueError ('GPU is not available')
         raise ValueError('Unknown device {0}. Expecting gpu or cpu'\
                          .format(device))
+def NDF_MASK(inputData, diffuswindow, regularisation_parameter, edge_parameter, iterations,
+                     time_marching_parameter, penalty_type, tolerance_param, device='cpu'):
+    if device == 'cpu':
+        return NDF_MASK_CPU(inputData,
+                     diffuswindow,
+                     regularisation_parameter,
+                     edge_parameter,
+                     iterations,
+                     time_marching_parameter,
+                     penalty_type,
+                     tolerance_param)
+    elif device == 'gpu' and gpu_enabled:
+        return NDF_MASK_CPU(inputData,
+                     diffuswindow,
+                     regularisation_parameter,
+                     edge_parameter,
+                     iterations,
+                     time_marching_parameter,
+                     penalty_type,
+                     tolerance_param)
+    else:
+        if not gpu_enabled and device == 'gpu':
+    	    raise ValueError ('GPU is not available')
+        raise ValueError('Unknown device {0}. Expecting gpu or cpu'\
+                         .format(device))
 def Diff4th(inputData, regularisation_parameter, edge_parameter, iterations,
                      time_marching_parameter, tolerance_param, device='cpu'):
     if device == 'cpu':
diff --git a/src/Python/src/cpu_regularisers.pyx b/src/Python/src/cpu_regularisers.pyx
index add641b..305ee1f 100644
--- a/src/Python/src/cpu_regularisers.pyx
+++ b/src/Python/src/cpu_regularisers.pyx
@@ -24,6 +24,7 @@ cdef extern float SB_TV_CPU_main(float *Input, float *Output, float *infovector,
 cdef extern float LLT_ROF_CPU_main(float *Input, float *Output, float *infovector, float lambdaROF, float lambdaLLT, int iterationsNumb, float tau, float epsil, int dimX, int dimY, int dimZ);
 cdef extern float TGV_main(float *Input, float *Output, float *infovector, float lambdaPar, float alpha1, float alpha0, int iterationsNumb, float L2, float epsil, int dimX, int dimY, int dimZ);
 cdef extern float Diffusion_CPU_main(float *Input, float *Output, float *infovector, float lambdaPar, float sigmaPar, int iterationsNumb, float tau, int penaltytype, float epsil, int dimX, int dimY, int dimZ);
+cdef extern float DiffusionMASK_CPU_main(float *Input, unsigned char *MASK, float *Output, float *infovector, int DiffusWindow, float lambdaPar, float sigmaPar, int iterationsNumb, float tau, int penaltytype, float epsil, int dimX, int dimY, int dimZ);
 cdef extern float Diffus4th_CPU_main(float *Input, float *Output,  float *infovector, float lambdaPar, float sigmaPar, int iterationsNumb, float tau, float epsil, int dimX, int dimY, int dimZ);
 cdef extern float dTV_FGP_CPU_main(float *Input, float *InputRef, float *Output, float *infovector, float lambdaPar, int iterationsNumb, float epsil, float eta, int methodTV, int nonneg, int dimX, int dimY, int dimZ);
 cdef extern float TNV_CPU_main(float *Input, float *u, float lambdaPar, int maxIter, float tol, int dimX, int dimY, int dimZ);
@@ -379,6 +380,42 @@ def NDF_3D(np.ndarray[np.float32_t, ndim=3, mode="c"] inputData,
     tolerance_param,
     dims[2], dims[1], dims[0])
     return (outputData,infovec)
+
+#****************************************************************#
+#********Constrained Nonlinear(Isotropic) Diffusion**************#
+#****************************************************************#
+def NDF_MASK_CPU(inputData, maskData, diffuswindow, regularisation_parameter, edge_parameter, iterationsNumb,time_marching_parameter, penalty_type, tolerance_param):
+    if inputData.ndim == 2:
+        return NDF_MASK_2D(inputData, maskData, diffuswindow, regularisation_parameter, edge_parameter, iterationsNumb, time_marching_parameter, penalty_type, tolerance_param)
+    elif inputData.ndim == 3:
+        return 0
+
+def NDF_MASK_2D(np.ndarray[np.float32_t, ndim=2, mode="c"] inputData,
+                    np.ndarray[np.uint8_t, ndim=2, mode="c"] maskData,
+                     int diffuswindow,
+                     float regularisation_parameter,
+                     float edge_parameter,
+                     int iterationsNumb,
+                     float time_marching_parameter,
+                     int penalty_type,
+                     float tolerance_param):
+    cdef long dims[2]
+    dims[0] = inputData.shape[0]
+    dims[1] = inputData.shape[1]
+
+    cdef np.ndarray[np.float32_t, ndim=2, mode="c"] outputData = \
+            np.zeros([dims[0],dims[1]], dtype='float32')
+    cdef np.ndarray[np.float32_t, ndim=1, mode="c"] infovec = \
+                np.zeros([2], dtype='float32')
+
+    # Run constrained nonlinear diffusion iterations for 2D data
+    DiffusionMASK_CPU_main(&inputData[0,0], &maskData[0,0], &outputData[0,0], &infovec[0],
+    diffuswindow, regularisation_parameter, edge_parameter, iterationsNumb,
+    time_marching_parameter, penalty_type,
+    tolerance_param,
+    dims[1], dims[0], 1)
+    return (outputData,infovec)
+
 #****************************************************************#
 #*************Anisotropic Fourth-Order diffusion*****************#
 #****************************************************************#