diff --git a/executables/WSIArithmetic/WSIArithmetic.cpp b/executables/WSIArithmetic/WSIArithmetic.cpp
index 80387ca2..09a0439d 100644
--- a/executables/WSIArithmetic/WSIArithmetic.cpp
+++ b/executables/WSIArithmetic/WSIArithmetic.cpp
@@ -61,7 +61,7 @@ int main(int argc, char *argv[]) {
       return 1;
     }
     MultiResolutionImageReader reader; 
-    MultiResolutionImage* input = reader.open(inputPth);
+    std::shared_ptr<MultiResolutionImage> input = std::shared_ptr<MultiResolutionImage>(reader.open(inputPth));
     CmdLineProgressMonitor monitor;
     if (input) {
       ArithmeticWholeSlideFilter fltr;
@@ -72,7 +72,6 @@ int main(int argc, char *argv[]) {
       if (!fltr.process()) {
         std::cerr << "ERROR: Processing failed" << std::endl;
       }
-      delete input;
     }
     else {
       std::cerr << "ERROR: Invalid input image" << std::endl;
diff --git a/executables/WSIConnectedComponents/WSIConnectedComponents.cpp b/executables/WSIConnectedComponents/WSIConnectedComponents.cpp
index 1ce0e2c0..22db78b8 100644
--- a/executables/WSIConnectedComponents/WSIConnectedComponents.cpp
+++ b/executables/WSIConnectedComponents/WSIConnectedComponents.cpp
@@ -59,7 +59,7 @@ int main(int argc, char *argv[]) {
       return 1;
     }
     MultiResolutionImageReader reader; 
-    MultiResolutionImage* input = reader.open(inputPth);
+    std::shared_ptr<MultiResolutionImage> input = std::shared_ptr<MultiResolutionImage>(reader.open(inputPth));
     CmdLineProgressMonitor monitor;
     if (input) {
       ConnectedComponentsWholeSlideFilter fltr;
@@ -69,7 +69,6 @@ int main(int argc, char *argv[]) {
       if (!fltr.process()) {
         std::cerr << "ERROR: Processing failed" << std::endl;
       }
-      delete input;
     }
     else {
       std::cerr << "ERROR: Invalid input image" << std::endl;
diff --git a/executables/WSIDistanceTransform/WSIDistanceTransform.cpp b/executables/WSIDistanceTransform/WSIDistanceTransform.cpp
index 87f32193..bbdd8496 100644
--- a/executables/WSIDistanceTransform/WSIDistanceTransform.cpp
+++ b/executables/WSIDistanceTransform/WSIDistanceTransform.cpp
@@ -59,7 +59,7 @@ int main(int argc, char *argv[]) {
       return 1;
     }
     MultiResolutionImageReader reader; 
-    MultiResolutionImage* input = reader.open(inputPth);
+    std::shared_ptr<MultiResolutionImage> input = std::shared_ptr<MultiResolutionImage>(reader.open(inputPth));
     CmdLineProgressMonitor monitor;
     if (input) {
       DistanceTransformWholeSlideFilter fltr;
@@ -70,7 +70,6 @@ int main(int argc, char *argv[]) {
       if (!fltr.process()) {
         std::cerr << "ERROR: Processing failed" << std::endl;
       }
-      delete input;
     }
     else {
       std::cerr << "ERROR: Invalid input image" << std::endl;
diff --git a/executables/WSILabelStatistics/WSILabelStatistics.cpp b/executables/WSILabelStatistics/WSILabelStatistics.cpp
index f05dfd2d..fd46a0de 100644
--- a/executables/WSILabelStatistics/WSILabelStatistics.cpp
+++ b/executables/WSILabelStatistics/WSILabelStatistics.cpp
@@ -59,7 +59,7 @@ int main(int argc, char *argv[]) {
       return 1;
     }
     MultiResolutionImageReader reader; 
-    MultiResolutionImage* input = reader.open(inputPth);
+    std::shared_ptr<MultiResolutionImage> input = std::shared_ptr<MultiResolutionImage>(reader.open(inputPth));
     CmdLineProgressMonitor monitor;
     if (input) {
       LabelStatisticsWholeSlideFilter fltr;
@@ -70,7 +70,6 @@ int main(int argc, char *argv[]) {
       if (!fltr.process()) {
         std::cerr << "ERROR: Processing failed" << std::endl;
       }
-      delete input;
     }
     else {
       std::cerr << "ERROR: Invalid input image" << std::endl;
diff --git a/executables/WSIThreshold/WSIThreshold.cpp b/executables/WSIThreshold/WSIThreshold.cpp
index 1c031cd7..218adff2 100644
--- a/executables/WSIThreshold/WSIThreshold.cpp
+++ b/executables/WSIThreshold/WSIThreshold.cpp
@@ -63,8 +63,8 @@ int main(int argc, char *argv[]) {
       std::cerr << "Use -h or --help for usage information" << std::endl;
       return 1;
     }
-    MultiResolutionImageReader reader; 
-    MultiResolutionImage* input = reader.open(inputPth);
+    MultiResolutionImageReader reader;
+    std::shared_ptr<MultiResolutionImage> input = std::shared_ptr<MultiResolutionImage>(reader.open(inputPth));
     CmdLineProgressMonitor monitor;
     if (input) {
       ThresholdWholeSlideFilter fltr;
@@ -77,7 +77,6 @@ int main(int argc, char *argv[]) {
       if (!fltr.process()) {
         std::cerr << "ERROR: Processing failed" << std::endl;
       }
-      delete input;
     }
     else {
       std::cerr << "ERROR: Invalid input image" << std::endl;
diff --git a/imgproc/wholeslide/ArithmeticWholeSlideFilter.cpp b/imgproc/wholeslide/ArithmeticWholeSlideFilter.cpp
index 3c77d932..0637a2a5 100644
--- a/imgproc/wholeslide/ArithmeticWholeSlideFilter.cpp
+++ b/imgproc/wholeslide/ArithmeticWholeSlideFilter.cpp
@@ -10,7 +10,6 @@
 #include <iostream>
 
 ArithmeticWholeSlideFilter::ArithmeticWholeSlideFilter() :
-_input(NULL),
 _monitor(NULL),
 _processedLevel(0),
 _outPath(""),
@@ -20,10 +19,9 @@ _expression("")
 }
 
 ArithmeticWholeSlideFilter::~ArithmeticWholeSlideFilter() {
-  _input = NULL;
 }
 
-void ArithmeticWholeSlideFilter::setInput(MultiResolutionImage* const input) {
+void ArithmeticWholeSlideFilter::setInput(const std::shared_ptr<MultiResolutionImage>& input) {
   _input = input;
 }
 
@@ -56,8 +54,9 @@ std::string ArithmeticWholeSlideFilter::getExpression() const {
 }
 
 bool ArithmeticWholeSlideFilter::process() {
-  std::vector<unsigned long long> dims = this->_input->getLevelDimensions(this->_processedLevel);
-  double downsample = this->_input->getLevelDownsample(this->_processedLevel);
+  std::shared_ptr<MultiResolutionImage> img = _input.lock();
+  std::vector<unsigned long long> dims = img->getLevelDimensions(this->_processedLevel);
+  double downsample = img->getLevelDownsample(this->_processedLevel);
 
   MultiResolutionImageWriter writer;
   writer.setColorType(pathology::ColorType::Monochrome);
@@ -65,7 +64,7 @@ bool ArithmeticWholeSlideFilter::process() {
   writer.setDataType(pathology::DataType::UInt32);
   writer.setInterpolation(pathology::Interpolation::NearestNeighbor);
   writer.setTileSize(512);
-  std::vector<double> spacing = _input->getSpacing();
+  std::vector<double> spacing = img->getSpacing();
   if (!spacing.empty()) {
     spacing[0] *= downsample;
     spacing[1] *= downsample;
@@ -89,7 +88,7 @@ bool ArithmeticWholeSlideFilter::process() {
   unsigned int* out_tile = new unsigned int[512 * 512];
   for (unsigned long long t_y = 0; t_y < dims[1]; t_y += 512) {
     for (unsigned long long t_x = 0; t_x < dims[0]; t_x += 512) {
-      this->_input->getRawRegion<unsigned int>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
+      img->getRawRegion<unsigned int>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
       for (unsigned int y = 0; y < 512; ++y) {
         for (unsigned int x = 0; x < 512; ++x) {
           float curVal = tile[y * 512 + x];
diff --git a/imgproc/wholeslide/ArithmeticWholeSlideFilter.h b/imgproc/wholeslide/ArithmeticWholeSlideFilter.h
index f6f89ecb..2fbec0ad 100644
--- a/imgproc/wholeslide/ArithmeticWholeSlideFilter.h
+++ b/imgproc/wholeslide/ArithmeticWholeSlideFilter.h
@@ -5,6 +5,7 @@
 #include <string>
 #include <vector>
 #include <map>
+#include <memory>
 
 class MultiResolutionImage;
 class ProgressMonitor;
@@ -12,7 +13,7 @@ class ProgressMonitor;
 class EXPORT_WHOLESLIDEFILTERS ArithmeticWholeSlideFilter {
 
 private:
-  MultiResolutionImage* _input;
+  std::weak_ptr<MultiResolutionImage> _input;
   ProgressMonitor* _monitor;
   unsigned int _processedLevel;
   std::string _outPath;
@@ -22,7 +23,7 @@ class EXPORT_WHOLESLIDEFILTERS ArithmeticWholeSlideFilter {
   ArithmeticWholeSlideFilter();
   virtual ~ArithmeticWholeSlideFilter();
 
-  void setInput(MultiResolutionImage* const input);
+  void setInput(const std::shared_ptr<MultiResolutionImage>& input);
   void setProcessedLevel(const unsigned int processedLevel);
   unsigned int getProcessedLevel();
   void setProgressMonitor(ProgressMonitor* progressMonitor);
diff --git a/imgproc/wholeslide/ConnectedComponentsWholeSlideFilter.cpp b/imgproc/wholeslide/ConnectedComponentsWholeSlideFilter.cpp
index 041a741a..7850d49b 100644
--- a/imgproc/wholeslide/ConnectedComponentsWholeSlideFilter.cpp
+++ b/imgproc/wholeslide/ConnectedComponentsWholeSlideFilter.cpp
@@ -111,7 +111,6 @@ void ConnectedComponentsWholeSlideFilter::DisjointSet::addElements(int numToAdd)
 }
 
 ConnectedComponentsWholeSlideFilter::ConnectedComponentsWholeSlideFilter() :
-_input(NULL),
 _monitor(NULL),
 _processedLevel(0),
 _outPath(""),
@@ -121,10 +120,9 @@ _threshold(0.5)
 }
 
 ConnectedComponentsWholeSlideFilter::~ConnectedComponentsWholeSlideFilter() {
-  _input = NULL;
 }
 
-void ConnectedComponentsWholeSlideFilter::setInput(MultiResolutionImage* const input) {
+void ConnectedComponentsWholeSlideFilter::setInput(const std::shared_ptr<MultiResolutionImage>& input) {
   _input = input;
 }
 
@@ -157,8 +155,9 @@ float ConnectedComponentsWholeSlideFilter::getThreshold() {
 }
 
 bool ConnectedComponentsWholeSlideFilter::process() const {
-  std::vector<unsigned long long> dims = this->_input->getLevelDimensions(this->_processedLevel);
-  double downsample = this->_input->getLevelDownsample(this->_processedLevel);
+  std::shared_ptr<MultiResolutionImage> img = _input.lock();
+  std::vector<unsigned long long> dims = img->getLevelDimensions(this->_processedLevel);
+  double downsample = img->getLevelDownsample(this->_processedLevel);
 
   MultiResolutionImageWriter writer;
   writer.setColorType(pathology::ColorType::Monochrome);
@@ -166,7 +165,7 @@ bool ConnectedComponentsWholeSlideFilter::process() const {
   writer.setDataType(pathology::DataType::UInt32);
   writer.setInterpolation(pathology::Interpolation::NearestNeighbor);
   writer.setTileSize(512);
-  std::vector<double> spacing = _input->getSpacing();
+  std::vector<double> spacing = img->getSpacing();
   if (!spacing.empty()) {
     spacing[0] *= downsample;
     spacing[1] *= downsample;
@@ -197,7 +196,7 @@ bool ConnectedComponentsWholeSlideFilter::process() const {
     for (unsigned long long t_y = 0; t_y < dims[1]; t_y += 512) {
       std::fill(buffer_t_x, buffer_t_x + 512, 0);
       for (unsigned long long t_x = 0; t_x < dims[0]; t_x += 512) {
-        this->_input->getRawRegion<float>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
+        img->getRawRegion<float>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
         std::fill(label_tile, label_tile + 512 * 512, 0);
         for (int y = 0; y < 512; ++y) {
           for (int x = 0; x < 512; ++x) {
diff --git a/imgproc/wholeslide/ConnectedComponentsWholeSlideFilter.h b/imgproc/wholeslide/ConnectedComponentsWholeSlideFilter.h
index 7427cab3..2eafb24c 100644
--- a/imgproc/wholeslide/ConnectedComponentsWholeSlideFilter.h
+++ b/imgproc/wholeslide/ConnectedComponentsWholeSlideFilter.h
@@ -4,6 +4,7 @@
 #include "config/pathology_config.h"
 #include <string>
 #include <vector>
+#include <memory>
 
 class MultiResolutionImage;
 class ProgressMonitor;
@@ -11,7 +12,7 @@ class ProgressMonitor;
 class EXPORT_WHOLESLIDEFILTERS ConnectedComponentsWholeSlideFilter {
 
 private:
-  MultiResolutionImage* _input;
+  std::weak_ptr<MultiResolutionImage> _input;
   ProgressMonitor* _monitor;
   unsigned int _processedLevel;
   std::string _outPath;
@@ -62,7 +63,7 @@ class EXPORT_WHOLESLIDEFILTERS ConnectedComponentsWholeSlideFilter {
   ConnectedComponentsWholeSlideFilter();
   virtual ~ConnectedComponentsWholeSlideFilter();
 
-  void setInput(MultiResolutionImage* const input);
+  void setInput(const std::shared_ptr<MultiResolutionImage>& input);
   void setProcessedLevel(const unsigned int processedLevel);
   unsigned int getProcessedLevel();
   void setProgressMonitor(ProgressMonitor* progressMonitor);
diff --git a/imgproc/wholeslide/DistanceTransformWholeSlideFilter.cpp b/imgproc/wholeslide/DistanceTransformWholeSlideFilter.cpp
index 8c341661..cf3903e0 100644
--- a/imgproc/wholeslide/DistanceTransformWholeSlideFilter.cpp
+++ b/imgproc/wholeslide/DistanceTransformWholeSlideFilter.cpp
@@ -7,7 +7,6 @@
 #include <set>
 
 DistanceTransformWholeSlideFilter::DistanceTransformWholeSlideFilter() :
-_input(NULL),
 _monitor(NULL),
 _processedLevel(0),
 _outPath("")
@@ -16,10 +15,9 @@ _outPath("")
 }
 
 DistanceTransformWholeSlideFilter::~DistanceTransformWholeSlideFilter() {
-  _input = NULL;
 }
 
-void DistanceTransformWholeSlideFilter::setInput(MultiResolutionImage* const input) {
+void DistanceTransformWholeSlideFilter::setInput(const std::shared_ptr<MultiResolutionImage>& input) {
   _input = input;
 }
 
@@ -44,8 +42,9 @@ ProgressMonitor* DistanceTransformWholeSlideFilter::getProgressMonitor() {
 }
 
 bool DistanceTransformWholeSlideFilter::process() const {
-  std::vector<unsigned long long> dims = this->_input->getLevelDimensions(this->_processedLevel);
-  double downsample = this->_input->getLevelDownsample(this->_processedLevel);
+  std::shared_ptr<MultiResolutionImage> img = _input.lock();
+  std::vector<unsigned long long> dims = img->getLevelDimensions(this->_processedLevel);
+  double downsample = img->getLevelDownsample(this->_processedLevel);
 
   MultiResolutionImageWriter writer;
   writer.setColorType(pathology::ColorType::Monochrome);
@@ -53,7 +52,7 @@ bool DistanceTransformWholeSlideFilter::process() const {
   writer.setDataType(pathology::DataType::UInt32);
   writer.setInterpolation(pathology::Interpolation::NearestNeighbor);
   writer.setTileSize(512);
-  std::vector<double> spacing = _input->getSpacing();
+  std::vector<double> spacing = img->getSpacing();
   if (!spacing.empty()) {
     spacing[0] *= downsample;
     spacing[1] *= downsample;
@@ -83,7 +82,7 @@ bool DistanceTransformWholeSlideFilter::process() const {
   for (unsigned long long t_y = 0; t_y < dims[1]; t_y += 512) {
     std::fill(buffer_t_x, buffer_t_x + 512, maxDist);
     for (unsigned long long t_x = 0; t_x < dims[0]; t_x += 512) {
-      this->_input->getRawRegion<unsigned char>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
+      img->getRawRegion<unsigned char>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
       std::fill(out_tile, out_tile + 512 * 512, (dims[0] + dims[1] / 2) + 1);
       int startX = 0;
       int startY = 0;
diff --git a/imgproc/wholeslide/DistanceTransformWholeSlideFilter.h b/imgproc/wholeslide/DistanceTransformWholeSlideFilter.h
index 3b7b2639..d9d653c3 100644
--- a/imgproc/wholeslide/DistanceTransformWholeSlideFilter.h
+++ b/imgproc/wholeslide/DistanceTransformWholeSlideFilter.h
@@ -4,6 +4,7 @@
 #include "config/pathology_config.h"
 #include <string>
 #include <vector>
+#include <memory>
 
 class MultiResolutionImage;
 class ProgressMonitor;
@@ -11,7 +12,7 @@ class ProgressMonitor;
 class EXPORT_WHOLESLIDEFILTERS DistanceTransformWholeSlideFilter {
 
 private:
-  MultiResolutionImage* _input;
+  std::weak_ptr<MultiResolutionImage> _input;
   ProgressMonitor* _monitor;
   unsigned int _processedLevel;
   std::string _outPath;
@@ -20,7 +21,7 @@ class EXPORT_WHOLESLIDEFILTERS DistanceTransformWholeSlideFilter {
   DistanceTransformWholeSlideFilter();
   virtual ~DistanceTransformWholeSlideFilter();
 
-  void setInput(MultiResolutionImage* const input);
+  void setInput(const std::shared_ptr<MultiResolutionImage>& input);
   void setProcessedLevel(const unsigned int processedLevel);
   unsigned int getProcessedLevel();
   void setProgressMonitor(ProgressMonitor* progressMonitor);
diff --git a/imgproc/wholeslide/LabelStatisticsWholeSlideFilter.cpp b/imgproc/wholeslide/LabelStatisticsWholeSlideFilter.cpp
index 90453b70..28410d89 100644
--- a/imgproc/wholeslide/LabelStatisticsWholeSlideFilter.cpp
+++ b/imgproc/wholeslide/LabelStatisticsWholeSlideFilter.cpp
@@ -9,7 +9,6 @@
 #include <iostream>
 
 LabelStatisticsWholeSlideFilter::LabelStatisticsWholeSlideFilter() :
-_input(NULL),
 _monitor(NULL),
 _processedLevel(0),
 _outPath("")
@@ -18,10 +17,9 @@ _outPath("")
 }
 
 LabelStatisticsWholeSlideFilter::~LabelStatisticsWholeSlideFilter() {
-  _input = NULL;
 }
 
-void LabelStatisticsWholeSlideFilter::setInput(MultiResolutionImage* const input) {
+void LabelStatisticsWholeSlideFilter::setInput(const std::shared_ptr<MultiResolutionImage>& input) {
   _input = input;
 }
 
@@ -51,8 +49,9 @@ std::vector<std::vector<float> > LabelStatisticsWholeSlideFilter::getLabelStatis
 
 bool LabelStatisticsWholeSlideFilter::process() {
   _labelStats.clear();
-  std::vector<unsigned long long> dims = this->_input->getLevelDimensions(this->_processedLevel);
-  double downsample = this->_input->getLevelDownsample(this->_processedLevel);
+  std::shared_ptr<MultiResolutionImage> img = _input.lock();
+  std::vector<unsigned long long> dims = img->getLevelDimensions(this->_processedLevel);
+  double downsample = img->getLevelDownsample(this->_processedLevel);
 
   std::ofstream csvfile;
   if (!_outPath.empty()) {
@@ -66,7 +65,7 @@ bool LabelStatisticsWholeSlideFilter::process() {
   unsigned int* tile = new unsigned int[512 * 512];
   for (unsigned long long t_y = 0; t_y < dims[1]; t_y += 512) {
     for (unsigned long long t_x = 0; t_x < dims[0]; t_x += 512) {
-      this->_input->getRawRegion<unsigned int>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
+      img->getRawRegion<unsigned int>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
       for (unsigned int y = 0; y < 512; ++y) {
         for (unsigned int x = 0; x < 512; ++x) {
           unsigned int curVal = tile[y * 512 + x];
diff --git a/imgproc/wholeslide/LabelStatisticsWholeSlideFilter.h b/imgproc/wholeslide/LabelStatisticsWholeSlideFilter.h
index 852fa3c7..4bbdc43c 100644
--- a/imgproc/wholeslide/LabelStatisticsWholeSlideFilter.h
+++ b/imgproc/wholeslide/LabelStatisticsWholeSlideFilter.h
@@ -5,6 +5,7 @@
 #include <string>
 #include <vector>
 #include <map>
+#include <memory>
 
 class MultiResolutionImage;
 class ProgressMonitor;
@@ -12,7 +13,7 @@ class ProgressMonitor;
 class EXPORT_WHOLESLIDEFILTERS LabelStatisticsWholeSlideFilter {
 
 private:
-  MultiResolutionImage* _input;
+  std::weak_ptr<MultiResolutionImage> _input;
   ProgressMonitor* _monitor;
   unsigned int _processedLevel;
   std::string _outPath;
@@ -22,7 +23,7 @@ class EXPORT_WHOLESLIDEFILTERS LabelStatisticsWholeSlideFilter {
   LabelStatisticsWholeSlideFilter();
   virtual ~LabelStatisticsWholeSlideFilter();
 
-  void setInput(MultiResolutionImage* const input);
+  void setInput(const std::shared_ptr<MultiResolutionImage>& input);
   void setProcessedLevel(const unsigned int processedLevel);
   unsigned int getProcessedLevel();
   void setProgressMonitor(ProgressMonitor* progressMonitor);
diff --git a/imgproc/wholeslide/ThresholdWholeSlideFilter.cpp b/imgproc/wholeslide/ThresholdWholeSlideFilter.cpp
index 187cb72a..aae753c1 100644
--- a/imgproc/wholeslide/ThresholdWholeSlideFilter.cpp
+++ b/imgproc/wholeslide/ThresholdWholeSlideFilter.cpp
@@ -9,7 +9,6 @@
 #include <iostream>
 
 ThresholdWholeSlideFilter::ThresholdWholeSlideFilter() :
-_input(NULL),
 _monitor(NULL),
 _processedLevel(0),
 _outPath(""),
@@ -21,10 +20,9 @@ _component(-1)
 }
 
 ThresholdWholeSlideFilter::~ThresholdWholeSlideFilter() {
-  _input = NULL;
 }
 
-void ThresholdWholeSlideFilter::setInput(MultiResolutionImage* const input) {
+void ThresholdWholeSlideFilter::setInput(const std::shared_ptr<MultiResolutionImage>& input) {
   _input = input;
 }
 
@@ -73,28 +71,29 @@ int ThresholdWholeSlideFilter::getComponent() const {
 }
 
 bool ThresholdWholeSlideFilter::process() {
-  std::vector<unsigned long long> dims = this->_input->getLevelDimensions(this->_processedLevel);
-  double downsample = this->_input->getLevelDownsample(this->_processedLevel);
+  std::shared_ptr<MultiResolutionImage> img = _input.lock();
+  std::vector<unsigned long long> dims = img->getLevelDimensions(this->_processedLevel);
+  double downsample = img->getLevelDownsample(this->_processedLevel);
 
   MultiResolutionImageWriter writer;
-  unsigned int outSamplesPerPixel = _input->getSamplesPerPixel();
-  unsigned int inSamplesPerPixel = _input->getSamplesPerPixel();
+  unsigned int outSamplesPerPixel = img->getSamplesPerPixel();
+  unsigned int inSamplesPerPixel = img->getSamplesPerPixel();
   if (_component >= inSamplesPerPixel) {
     std::cerr << "ERROR: Selected component is larger than number of input components, fallback to all components" << std::endl;
     _component = -1;
   }
-  if (_component >= 0 || _input->getSamplesPerPixel() == 1) {
+  if (_component >= 0 || img->getSamplesPerPixel() == 1) {
     writer.setColorType(pathology::ColorType::Monochrome);
     outSamplesPerPixel = 1;
   } else {
     writer.setColorType(pathology::ColorType::Indexed);
-    writer.setNumberOfIndexedColors(_input->getSamplesPerPixel());
+    writer.setNumberOfIndexedColors(img->getSamplesPerPixel());
   }
   writer.setCompression(pathology::Compression::LZW);
   writer.setDataType(pathology::DataType::UChar);
   writer.setInterpolation(pathology::Interpolation::NearestNeighbor);
   writer.setTileSize(512);
-  std::vector<double> spacing = _input->getSpacing();
+  std::vector<double> spacing = img->getSpacing();
   if (!spacing.empty()) {
     spacing[0] *= downsample;
     spacing[1] *= downsample;
@@ -107,14 +106,14 @@ bool ThresholdWholeSlideFilter::process() {
   writer.setProgressMonitor(_monitor);
   writer.writeImageInformation(dims[0], dims[1]);
 
-  float* tile = new float[512 * 512 * _input->getSamplesPerPixel()];
+  float* tile = new float[512 * 512 * img->getSamplesPerPixel()];
   unsigned char* out_tile = new unsigned char[512 * 512 * outSamplesPerPixel];
   for (unsigned long long t_y = 0; t_y < dims[1]; t_y += 512) {
     for (unsigned long long t_x = 0; t_x < dims[0]; t_x += 512) {
-      this->_input->getRawRegion<float>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
+      img->getRawRegion<float>(static_cast<unsigned long long>(t_x*downsample), static_cast<unsigned long long>(t_y*downsample), 512, 512, this->_processedLevel, tile);
       for (unsigned int y = 0; y < 512; ++y) {
         for (unsigned int x = 0; x < 512; ++x) {
-          for (unsigned int c = 0; c < _input->getSamplesPerPixel(); ++c) {
+          for (unsigned int c = 0; c < img->getSamplesPerPixel(); ++c) {
             if (c == _component) {
               float curVal = tile[y * 512 * inSamplesPerPixel + x * inSamplesPerPixel + c];
               if (curVal >= _lowerThreshold && curVal < _upperThreshold) {
diff --git a/imgproc/wholeslide/ThresholdWholeSlideFilter.h b/imgproc/wholeslide/ThresholdWholeSlideFilter.h
index 67dbff1f..2e63a548 100644
--- a/imgproc/wholeslide/ThresholdWholeSlideFilter.h
+++ b/imgproc/wholeslide/ThresholdWholeSlideFilter.h
@@ -5,6 +5,7 @@
 #include <string>
 #include <vector>
 #include <map>
+#include <memory>
 
 class MultiResolutionImage;
 class ProgressMonitor;
@@ -12,7 +13,7 @@ class ProgressMonitor;
 class EXPORT_WHOLESLIDEFILTERS ThresholdWholeSlideFilter {
 
 private:
-  MultiResolutionImage* _input;
+  std::weak_ptr<MultiResolutionImage> _input;
   ProgressMonitor* _monitor;
   unsigned int _processedLevel;
   std::string _outPath;
@@ -25,7 +26,7 @@ class EXPORT_WHOLESLIDEFILTERS ThresholdWholeSlideFilter {
   ThresholdWholeSlideFilter();
   virtual ~ThresholdWholeSlideFilter();
 
-  void setInput(MultiResolutionImage* const input);
+  void setInput(const std::shared_ptr<MultiResolutionImage>& input);
   void setProcessedLevel(const unsigned int processedLevel);
   unsigned int getProcessedLevel();
   void setProgressMonitor(ProgressMonitor* progressMonitor);