diff --git a/CloneSource.cpp b/CloneSource.cpp
index 2a63827..f24a87d 100644
--- a/CloneSource.cpp
+++ b/CloneSource.cpp
@@ -150,6 +150,9 @@ void CloneSource::setFilter(FrameBufferFilter::Type T)
     case FrameBufferFilter::FILTER_BLUR:
         filter_ = new BlurFilter;
         break;
+    case FrameBufferFilter::FILTER_SHARPEN:
+        filter_ = new SharpenFilter;
+        break;
     case FrameBufferFilter::FILTER_IMAGE:
         filter_ = new ImageFilter;
         break;
diff --git a/FrameBufferFilter.cpp b/FrameBufferFilter.cpp
index a2d642d..85564d1 100644
--- a/FrameBufferFilter.cpp
+++ b/FrameBufferFilter.cpp
@@ -6,7 +6,7 @@
 #include "FrameBufferFilter.h"
 
 const char* FrameBufferFilter::type_label[FrameBufferFilter::FILTER_INVALID] = {
-    "None", "Delay", "Blur", "Shader code"
+    "None", "Delay", "Blur", "Sharpen", "Shader code"
 };
 
 FrameBufferFilter::FrameBufferFilter() : enabled_(true), input_(nullptr)
diff --git a/FrameBufferFilter.h b/FrameBufferFilter.h
index 0b499b8..0eae509 100644
--- a/FrameBufferFilter.h
+++ b/FrameBufferFilter.h
@@ -21,6 +21,7 @@ public:
         FILTER_PASSTHROUGH = 0,
         FILTER_DELAY,
         FILTER_BLUR,
+        FILTER_SHARPEN,
         FILTER_IMAGE,
         FILTER_INVALID
     } Type;
diff --git a/ImGuiVisitor.cpp b/ImGuiVisitor.cpp
index 8c85d0f..ed82e7d 100644
--- a/ImGuiVisitor.cpp
+++ b/ImGuiVisitor.cpp
@@ -818,6 +818,51 @@ void ImGuiVisitor::visit (BlurFilter& f)
 
 }
 
+void ImGuiVisitor::visit (SharpenFilter& f)
+{
+    std::ostringstream oss;
+    oss << "Blur ";
+
+    // Method selection
+    if (ImGuiToolkit::IconButton(7, 16)) {
+        f.setMethod( 0 );
+        oss << SharpenFilter::method_label[0];
+        Action::manager().store(oss.str());
+    }
+    ImGui::SameLine(0, IMGUI_SAME_LINE);
+    ImGui::SetNextItemWidth(IMGUI_RIGHT_ALIGN);
+    int m = (int) f.method();
+    if (ImGui::Combo("Method", &m, SharpenFilter::method_label, IM_ARRAYSIZE(SharpenFilter::method_label) )) {
+        f.setMethod( m );
+        oss << SharpenFilter::method_label[m];
+        Action::manager().store(oss.str());
+    }
+
+
+    // List of parameters
+    std::map<std::string, float> filter_parameters = f.program().parameters();
+    for (auto param = filter_parameters.begin(); param != filter_parameters.end(); ++param)
+    {
+        ImGui::PushID( param->first.c_str() );
+        float v = param->second;
+        if (ImGuiToolkit::IconButton(13, 14)) {
+            v = 0.f;
+            f.setProgramParameter(param->first, v);
+        }
+        ImGui::SameLine(0, IMGUI_SAME_LINE);
+        ImGui::SetNextItemWidth(IMGUI_RIGHT_ALIGN);
+        if (ImGui::SliderFloat( param->first.c_str(), &v, 0.f, 1.f, "%.2f")) {
+            f.setProgramParameter(param->first, v);
+        }
+        if (ImGui::IsItemDeactivatedAfterEdit()) {
+            oss << SharpenFilter::method_label[ f.method() ];
+            oss << " : " << param->first << " " << std::setprecision(3) <<param->second;
+            Action::manager().store(oss.str());
+        }
+        ImGui::PopID();
+    }
+}
+
 void ImGuiVisitor::visit (ImageFilter& f)
 {
     // Selection of Algorithm
diff --git a/ImGuiVisitor.h b/ImGuiVisitor.h
index f127167..fac88c9 100644
--- a/ImGuiVisitor.h
+++ b/ImGuiVisitor.h
@@ -40,6 +40,7 @@ public:
     void visit (PassthroughFilter&) override;
     void visit (DelayFilter&) override;
     void visit (BlurFilter&) override;
+    void visit (SharpenFilter&) override;
     void visit (ImageFilter&) override;
 };
 
diff --git a/ImageFilter.cpp b/ImageFilter.cpp
index 9aad120..3fc2623 100644
--- a/ImageFilter.cpp
+++ b/ImageFilter.cpp
@@ -485,15 +485,15 @@ void ImageFilter::setProgramParameter(const std::string &p, float value)
 ////////////////////////////////////////
 
 const char* BlurFilter::method_label[BlurFilter::BLUR_INVALID] = {
-    "Gaussian", "Hash", "Openning", "Closing", "Fast 2x2"
+    "Gaussian", "Scattered", "Opening", "Closing", "Fast"
 };
 
 std::vector< FilteringProgram > BlurFilter::programs_ = {
-    FilteringProgram("Gaussian", "shaders/filters/blur_1.glsl",     "shaders/filters/blur_2.glsl",     { { "Radius", 0.5} }),
-    FilteringProgram("Hashed",   "shaders/filters/hashedblur.glsl", "",     { { "Iterations", 0.5 }, { "Radius", 0.5} }),
-    FilteringProgram("Openning", "shaders/filters/hashederosion.glsl", "shaders/filters/hasheddilation.glsl",   { { "Radius", 0.5} }),
-    FilteringProgram("Closing",  "shaders/filters/hasheddilation.glsl", "shaders/filters/hashederosion.glsl",   { { "Radius", 0.5} }),
-    FilteringProgram("Fast 2x2", "shaders/filters/blur.glsl",   "",     { })
+    FilteringProgram("Gaussian", "shaders/filters/blur_1.glsl",        "shaders/filters/blur_2.glsl",     { { "Radius", 0.5} }),
+    FilteringProgram("Scattered","shaders/filters/hashedblur.glsl",    "",     { { "Radius", 0.5}, { "Iterations", 0.25 } }),
+    FilteringProgram("Opening",  "shaders/filters/hashederosion.glsl", "shaders/filters/hasheddilation.glsl",   { { "Radius", 0.5} }),
+    FilteringProgram("Closing",  "shaders/filters/hasheddilation.glsl","shaders/filters/hashederosion.glsl",   { { "Radius", 0.5} }),
+    FilteringProgram("Fast",     "shaders/filters/blur.glsl", "", { })
 };
 
 BlurFilter::BlurFilter (): ImageFilter(), method_(BLUR_INVALID), mipmap_buffer_(nullptr)
@@ -588,4 +588,37 @@ void BlurFilter::accept (Visitor& v)
 }
 
 
+////////////////////////////////////////
+/////                                 //
+////  SHARPENING FILTERS             ///
+///                                 ////
+////////////////////////////////////////
+
+const char* SharpenFilter::method_label[SharpenFilter::SHARPEN_INVALID] = {
+    "Unsharp mask", "Convolution", "Edge"
+};
+
+std::vector< FilteringProgram > SharpenFilter::programs_ = {
+    FilteringProgram("Unsharp Mask", "shaders/filters/sharpen_1.glsl",  "shaders/filters/sharpen_2.glsl",     { { "Amount", 0.5} }),
+    FilteringProgram("Sharpen",      "shaders/filters/sharp.glsl",      "",     { { "Amount", 0.5} }),
+    FilteringProgram("Sharp Edge",   "shaders/filters/bilinear.glsl",   "shaders/filters/sharpenedge.glsl",  { { "Strength", 0.5} }),
+};
+
+SharpenFilter::SharpenFilter (): ImageFilter(), method_(SHARPEN_INVALID)
+{
+}
+
+void SharpenFilter::setMethod(int method)
+{
+    method_ = (SharpenMethod) CLAMP(method, SHARPEN_MASK, SHARPEN_INVALID-1);
+    setProgram( programs_[ (int) method_] );
+}
+
+void SharpenFilter::accept (Visitor& v)
+{
+    FrameBufferFilter::accept(v);
+    v.visit(*this);
+}
+
+
 
diff --git a/ImageFilter.h b/ImageFilter.h
index 7d1068c..862d9b8 100644
--- a/ImageFilter.h
+++ b/ImageFilter.h
@@ -137,6 +137,33 @@ private:
 };
 
 
+class SharpenFilter : public ImageFilter
+{
+public:
+
+    SharpenFilter();
+
+    // Algorithms used for sharpen
+    typedef enum {
+        SHARPEN_MASK = 0,
+        SHARPEN_CONVOLUTION,
+        SHARPEN_EDGE,
+        SHARPEN_INVALID
+    } SharpenMethod;
+    static const char* method_label[SHARPEN_INVALID];
+    SharpenMethod method () const { return method_; }
+    void setMethod(int method);
+
+    // implementation of FrameBufferFilter
+    Type type() const override { return FrameBufferFilter::FILTER_SHARPEN; }
+
+    void accept (Visitor& v) override;
+
+private:
+    SharpenMethod method_;
+    static std::vector< FilteringProgram > programs_;
+};
+
 
 
 #endif // IMAGEFILTER_H
diff --git a/Visitor.h b/Visitor.h
index 7b5b6be..9bafd86 100644
--- a/Visitor.h
+++ b/Visitor.h
@@ -45,6 +45,7 @@ class FrameBufferFilter;
 class PassthroughFilter;
 class DelayFilter;
 class BlurFilter;
+class SharpenFilter;
 class ImageFilter;
 
 class SourceCallback;
@@ -106,6 +107,7 @@ public:
     virtual void visit (PassthroughFilter&) {}
     virtual void visit (DelayFilter&) {}
     virtual void visit (BlurFilter&) {}
+    virtual void visit (SharpenFilter&) {}
     virtual void visit (ImageFilter&) {}
 
     virtual void visit (SourceCallback&) {}
diff --git a/rsc/shaders/filters/hasheddilation.glsl b/rsc/shaders/filters/hasheddilation.glsl
index df7cef5..a432813 100644
--- a/rsc/shaders/filters/hasheddilation.glsl
+++ b/rsc/shaders/filters/hasheddilation.glsl
@@ -37,10 +37,10 @@ void mainImage( out vec4 fragColor, in vec2 fragCoord )
     float ar = iResolution.y / iResolution.x ;
     float R  = 0.25 * Radius ;
 
-    vec4 O = vec4(1.);
+    vec4  O = vec4(1.);
     float N = 17;
     for (float i = 0.; i < N; i++) {
-        vec2 q = vec2(cos(TWOPI*((i+.5)/N)) * ar, sin(TWOPI*(i+.5)/N)) * Hash01(uv, floatBitsToUint(i));
+        vec2 q = vec2(cos(TWOPI*((i+.5)/N)) * ar, sin(TWOPI*(i+.5)/N)) * (0.1 + 0.9 * Hash01(uv, floatBitsToUint(i)));
         // vec2 q = vec2(cos(TWOPI*((i+.5)/N)) * ar, sin(TWOPI*(i+.5)/N)) * hash(vec2(i + 12., uv.x * uv.y + 24.));
         O = min( texture(iChannel0, uv + q*R), O );
     }
diff --git a/rsc/shaders/filters/hashederosion.glsl b/rsc/shaders/filters/hashederosion.glsl
index 0d0592c..f558e62 100644
--- a/rsc/shaders/filters/hashederosion.glsl
+++ b/rsc/shaders/filters/hashederosion.glsl
@@ -38,10 +38,10 @@ void mainImage( out vec4 fragColor, in vec2 fragCoord )
     float ar = iResolution.y / iResolution.x ;
     float R  = 0.25 * Radius ;
 
-    vec4 O = vec4(0.);
+    vec4  O = vec4(0.);
     float N = 17;
     for (float i = 0.; i < N; i++) {
-        vec2 q = vec2(cos(TWOPI*i/N) * ar, sin(TWOPI*i/N)) * Hash01(uv, floatBitsToUint(i) );
+        vec2 q = vec2(cos(TWOPI*i/N) * ar, sin(TWOPI*i/N)) * (0.1 + 0.9 * Hash01(uv, floatBitsToUint(i)));
         // vec2 q = vec2(cos(TWOPI*i/N) * ar, sin(TWOPI*i/N)) * hash(vec2(i, uv.x + uv.y));
         O = max( texture(iChannel0, uv + q*R), O );
     }
diff --git a/rsc/shaders/filters/sharpen_1.glsl b/rsc/shaders/filters/sharpen_1.glsl
index afde1f9..9ae4eaf 100644
--- a/rsc/shaders/filters/sharpen_1.glsl
+++ b/rsc/shaders/filters/sharpen_1.glsl
@@ -1,30 +1,22 @@
 uniform float Amount;
 
-float SCurve (float x) {
-    x = x * 2.0 - 1.0;
-    return -x * abs(x) * 0.5 + x + 0.5;
-}
-
-vec3 BlurV (sampler2D source, vec2 uv, float step, float radius) {
-    vec3 C = vec3(0.0); 
-    float divisor = 0.0; 
-    float weight = 0.0;
-    float radiusMultiplier = 1.0 / max(1.0, radius);
-
-    // loop on pixels in Y to apply vertical blur
-    for (float y = -radius; y <= radius; y++) {
-        weight = SCurve(1.0 - (abs(y) * radiusMultiplier)); 
-        C += texture(source, uv + vec2(0.0, y * step)).rgb * weight;
-        divisor += weight; 
+#define N 7
+vec4 blur1D(vec2 U, vec2 D, float rad)
+{
+    float w = rad * iResolution.y;
+    float z = ceil(max(0.,log2(w/float(N)))); // LOD  N/w = res/2^z
+    vec4  O = vec4(0);
+    float r = float(N-1)/2., g, t=0., x;
+    for( int k=0; k<N; k++ ) {
+        x = float(k)/r -1.;
+        t += g = exp(-2.*x*x );
+        O += g * textureLod(iChannel0, (U + w*x*D) / iResolution.xy, z );
     }
-
-    return C / divisor;
+    return O/t;
 }
 
 void mainImage( out vec4 fragColor, in vec2 fragCoord )
-{
-    vec2 uv = fragCoord.xy / iResolution.xy;
-    
+{    
     // Apply vertical blur
-    fragColor = vec4( BlurV(iChannel0, uv, 1.0 / iResolution.y, mix(1.0, 0.1*iResolution.y, Amount)), 1.0);
+    fragColor = blur1D(fragCoord, vec2(1,0), 0.1 * Amount);
 }
diff --git a/rsc/shaders/filters/sharpen_2.glsl b/rsc/shaders/filters/sharpen_2.glsl
index 1415e87..255304d 100644
--- a/rsc/shaders/filters/sharpen_2.glsl
+++ b/rsc/shaders/filters/sharpen_2.glsl
@@ -1,37 +1,29 @@
 uniform float Amount;
 
-float SCurve (float x) {
-    x = x * 2.0 - 1.0;
-    return -x * abs(x) * 0.5 + x + 0.5;
-}
-
-vec3 BlurH (sampler2D source, vec2 uv, float step, float radius) {
-    vec3 C = vec3(0.0); 
-    float divisor = 0.0; 
-    float weight = 0.0;
-    float radiusMultiplier = 1.0 / max(1.0, radius);
-
-    // loop on pixels in X to apply horizontal blur
-    for (float x = -radius; x <= radius; x++) {
-        weight = SCurve(1.0 - (abs(x) * radiusMultiplier)); 
-        C += texture(source, uv + vec2(x * step, 0.0)).rgb * weight;
-        divisor += weight; 
+#define N 7
+vec4 blur1D(vec2 U, vec2 D, float rad)
+{
+    float w = rad * iResolution.y;
+    float z = ceil(max(0.,log2(w/float(N)))); // LOD  N/w = res/2^z
+    vec4  O = vec4(0);
+    float r = float(N-1)/2., g, t=0., x;
+    for( int k=0; k<N; k++ ) {
+        x = float(k)/r -1.;
+        t += g = exp(-2.*x*x );
+        O += g * textureLod(iChannel0, (U + w*x*D) / iResolution.xy, z );
     }
-
-    return C / divisor;
+    return O/t;
 }
 
 void mainImage( out vec4 fragColor, in vec2 fragCoord )
 {
-    vec2 uv = fragCoord.xy / iResolution.xy;
-    
     // get original image
-    vec3 c = texture(iChannel1, uv).rgb;
+    vec4 c = texture(iChannel1, fragCoord.xy / iResolution.xy);
 
     // Remove blurred image to original image
-    vec3 lumcoeff = vec3(0.299,0.587,0.114);
-    float luminance = dot( c - BlurH(iChannel0, uv, 1.0 / iResolution.x, mix(1.0, 0.1*iResolution.y, Amount) ), lumcoeff);
+    vec4 lumcoeff = vec4(0.299, 0.587, 0.114, 1.);
+    float luminance = dot( c - blur1D(fragCoord, vec2(0,1), 0.1 * Amount ), lumcoeff);
 
     // composition
-    fragColor = vec4( c + vec3(luminance), 1.0);
+    fragColor =  c + vec4(luminance);
 }