From c9c02c137bc6d542882ae4dd895b4dd29f6d864b Mon Sep 17 00:00:00 2001
From: Desmis <jdesmis@gmail.com>
Date: Wed, 13 Sep 2017 08:49:56 +0200
Subject: [PATCH] change calculation in curve brightness CIECAM

---
 rtengine/improcfun.cc | 37 +++++++++++++++++++++++++++++--------
 1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/rtengine/improcfun.cc b/rtengine/improcfun.cc
index 6d6fccc88..c8faa4ce0 100644
--- a/rtengine/improcfun.cc
+++ b/rtengine/improcfun.cc
@@ -1681,10 +1681,11 @@ void ImProcFunctions::ciecam_02float (CieImage* ncie, float adap, int begh, int
             }
         }
 
-        if (alg >= 2 && la < 200.f) {
-            la = 200.f;
-        }
-
+        /*
+                if (alg >= 2 && la < 200.f) {
+                    la = 200.f;
+                }
+        */
         const float la2 = float (params->colorappearance.adaplum);
 
         // level of adaptation
@@ -1775,6 +1776,7 @@ void ImProcFunctions::ciecam_02float (CieImage* ncie, float adap, int begh, int
             }
 
             float sum = 0.f;
+            float sumQ = 0.f;
 
 #ifdef _OPENMP
             const int numThreads = min (max (width * height / 65536, 1), omp_get_max_threads());
@@ -1794,7 +1796,7 @@ void ImProcFunctions::ciecam_02float (CieImage* ncie, float adap, int begh, int
                     hist16Qthr.clear();
                 }
 
-                #pragma omp for reduction(+:sum)
+                #pragma omp for reduction(+:sum,sumQ)
 
                 for (int i = 0; i < height; i++)
                     for (int j = 0; j < width; j++) { //rough correspondence between L and J
@@ -1839,11 +1841,26 @@ void ImProcFunctions::ciecam_02float (CieImage* ncie, float adap, int begh, int
                             hist16Jthr[ (int) ((koef * lab->L[i][j]))]++;  //evaluate histogram luminance L # J
                         }
 
+                        //estimation of wh only with La
+                        float whestim = 500.f;
+
+                        if (la < 200.f) {
+                            whestim = 200.f;
+                        } else if (la < 2500.f) {
+                            whestim = 350.f;
+                        } else {
+                            whestim = 500.f;
+                        }
+
                         if (needQ) {
-                            hist16Qthr[ (int) (sqrtf ((koef * (lab->L[i][j])) * 32768.f))]++;  //for brightness Q : approximation for Q=wh*sqrt(J/100)  J not equal L
+                            hist16Qthr[CLIP ((int) (32768.f * sqrt ((koef * (lab->L[i][j])) / 32768.f)))]++;  //for brightness Q : approximation for Q=wh*sqrt(J/100)  J not equal L
+                            //perhaps  needs to introduce whestim ??
+                            //   hist16Qthr[ (int) (sqrtf ((koef * (lab->L[i][j])) * 32768.f))]++;  //for brightness Q : approximation for Q=wh*sqrt(J/100)  J not equal L
                         }
 
                         sum += koef * lab->L[i][j]; //evaluate mean J to calculate Yb
+                        sumQ += whestim * sqrt ((koef * (lab->L[i][j])) / 32768.f);
+                        //can be used in case of...
                     }
 
                 #pragma omp critical
@@ -1857,14 +1874,16 @@ void ImProcFunctions::ciecam_02float (CieImage* ncie, float adap, int begh, int
                     }
 
                 }
+                float meanQ;
 
                 if (std::isnan (mean)) {
                     mean = (sum / ((height) * width)) / 327.68f; //for Yb  for all image...if one day "pipette" we can adapt Yb for each zone
+                    meanQ = (sumQ / ((height) * width));//in case of
+
                 }
             }
 
 
-
             //evaluate lightness, contrast
         }
 
@@ -1937,6 +1956,8 @@ void ImProcFunctions::ciecam_02float (CieImage* ncie, float adap, int begh, int
 
         float cz, wh, pfl;
         Ciecam02::initcam1float (gamu, yb, pilot, f, la, xw, yw, zw, n, d, nbb, ncb, cz, aw, wh, pfl, fl, c);
+        //printf ("wh=%f \n", wh);
+
         const float pow1 = pow_F ( 1.64f - pow_F ( 0.29f, n ), 0.73f );
         float nj, nbbj, ncbj, czj, awj, flj;
         Ciecam02::initcam2float (gamu, yb2, pilotout, f2,  la2,  xw2,  yw2,  zw2, nj, dj, nbbj, ncbj, czj, awj, flj);
@@ -1954,7 +1975,7 @@ void ImProcFunctions::ciecam_02float (CieImage* ncie, float adap, int begh, int
         const bool LabPassOne = ! ((params->colorappearance.tonecie && (epdEnabled)) || (params->sharpening.enabled && settings->autocielab && execsharp)
                                    || (params->dirpyrequalizer.enabled && settings->autocielab) || (params->defringe.enabled && settings->autocielab)  || (params->sharpenMicro.enabled && settings->autocielab)
                                    || (params->impulseDenoise.enabled && settings->autocielab) ||  (params->colorappearance.badpixsl > 0 && settings->autocielab));
-
+        //printf("coQ=%f\n", coefQ);
 
         if (needJ) {
             if (!CAMBrightCurveJ) {