Amaze+VNG4: created own entry in demosaic combobox, cleaned code

rtengine/rt_algo.cc

@@ -25,7 +25,31 @@
 #include <omp.h>
 #endif
 
+#include "gauss.h"
+#include "opthelper.h"
 #include "rt_algo.h"
+#include "rt_math.h"
+#include "sleef.c"
+
+namespace {
+float calcBlendFactor(float val, float threshold) {
+    // sigmoid function
+    // result is in ]0;1] range
+    // inflexion point is at (x, y) (threshold, 0.5)
+    return 1.f / (1.f + xexpf(16.f - 16.f * val / threshold));
+}
+
+#ifdef __SSE2__
+vfloat calcBlendFactor(vfloat valv, vfloat thresholdv) {
+    // sigmoid function
+    // result is in ]0;1] range
+    // inflexion point is at (x, y) (threshold, 0.5)
+    const vfloat onev = F2V(1.f);
+    const vfloat c16v = F2V(16.f);
+    return onev / (onev + xexpf(c16v - c16v * valv / thresholdv));
+}
+#endif
+}
 
 namespace rtengine
 {
@@ -164,4 +188,73 @@ void findMinMaxPercentile(const float* data, size_t size, float minPrct, float&
     maxOut += minVal;
 }
 
+void buildBlendMask(float** luminance, rtengine::JaggedArray<float> &blend, int W, int H, float contrastThreshold, float amount) {
+
+    if(contrastThreshold == 0.f) {
+        for(int j = 0; j < H; ++j) {
+            for(int i = 0; i < W; ++i) {
+                blend[j][i] = 1.f;
+            }
+        }
+    } else {
+        constexpr float scale = 0.0625f / 327.68f;
+#ifdef _OPENMP
+        #pragma omp parallel
+#endif
+    {
+#ifdef __SSE2__
+        const vfloat contrastThresholdv = F2V(contrastThreshold);
+        const vfloat scalev = F2V(scale);
+        const vfloat amountv = F2V(amount);
+#endif
+#ifdef _OPENMP
+        #pragma omp for schedule(dynamic,16)
+#endif
+
+        for(int j = 2; j < H - 2; ++j) {
+            int i = 2;
+#ifdef __SSE2__
+            for(; i < W - 5; i += 4) {
+                vfloat contrastv = vsqrtf(SQRV(LVFU(luminance[j][i+1]) - LVFU(luminance[j][i-1])) + SQRV(LVFU(luminance[j+1][i]) - LVFU(luminance[j-1][i])) +
+                                          SQRV(LVFU(luminance[j][i+2]) - LVFU(luminance[j][i-2])) + SQRV(LVFU(luminance[j+2][i]) - LVFU(luminance[j-2][i]))) * scalev;
+
+                STVFU(blend[j][i], amountv * calcBlendFactor(contrastv, contrastThresholdv));
+            }
+#endif
+            for(; i < W - 2; ++i) {
+
+                float contrast = sqrtf(rtengine::SQR(luminance[j][i+1] - luminance[j][i-1]) + rtengine::SQR(luminance[j+1][i] - luminance[j-1][i]) + 
+                                       rtengine::SQR(luminance[j][i+2] - luminance[j][i-2]) + rtengine::SQR(luminance[j+2][i] - luminance[j-2][i])) * scale;
+
+                blend[j][i] = amount * calcBlendFactor(contrast, contrastThreshold);
+            }
+        }
+#ifdef _OPENMP
+        #pragma omp single
+#endif
+        {
+            // upper border
+            for(int j = 0; j < 2; ++j) {
+                for(int i = 2; i < W - 2; ++i) {
+                    blend[j][i] = blend[2][i];
+                }
+            }
+            // lower border
+            for(int j = H - 2; j < H; ++j) {
+                for(int i = 2; i < W - 2; ++i) {
+                    blend[j][i] = blend[H-3][i];
+                }
+            }
+            for(int j = 0; j < H; ++j) {
+                // left border
+                blend[j][0] = blend[j][1] = blend[j][2];
+                // right border
+                blend[j][W - 2] = blend[j][W - 1] = blend[j][W - 3];
+            }
+        }
+        // blur blend mask to smooth transitions
+        gaussianBlur(blend, blend, W, H, 2.0);
+    }
+    }
+}
 }